Heel Pain in Horses

Understanding navicular conditions to improve your horse's health

by R. Paul Schwab

Most horse owners have heard the dreaded term "navicular disease." It falls in the category with Strangles and colic as far as terms you hope your veterinarian doesn’t mention when discussing the health and soundness of your horse. But what is navicular disease?

Navicular disease has been used over the years to describe a syndrome of pain and inflammation caused by damage to bone and other soft tissues in a horse's heel, usually related to conformation of the pastern and hoof, use of the horse, and breed. This term is better described as navicular syndrome, and more recently, caudal heel pain. Navicular disease refers to a problem with the navicular bone itself whereas navicular syndrome is a term reserved to describe disease that involves tissues associated with the navicular bone. Caudal heel pain describes pain in the navicular bone, deep digital flexor tendon and other associated soft tissues in the heel of the horse.

Anatomy

The navicular bone is a small bone similar to a kneecap in the sense that it floats between the pastern bone and coffin bone and guides the deep digital flexor tendon across the coffin joint and onto the coffin bone. There are multiple soft tissues involved with the navicular bone, including the ligaments that attach it to the coffin and pastern bones as well as the associated joint capsules and, of course, the deep digital flexor tendon.

Pain in this area of the heel is almost exclusively related to hoof and pastern conformation and/or biomechanics. Exceptions would be traumatic injuries such as puncture wounds, lacerations, etc. Horses with low, under-run heels and long toes and horses with short, upright pasterns are the classic heel pain horses. Quarter Horses are more commonly affected because these conformations are more common to the breed as well as the type of work they do. Cutting, gaming and reining horses use their front ends more than other horses, putting more strain on the heels.

Diagnosis of Caudal Heel Pain

Diagnosis of heel pain, as with any other lameness. is made with a combination of examination, history and diagnostic imaging (radiographs and/or MRI). Riders often complain of the horse not turning to one side properly or that the gait has become "choppy." More severe or chronic cases will stand with one foot pointed out in front. Other horses are just more reluctant to work. Foot testers will usually indicate pain at the front or middle of the frog. To get a more specific diagnosis, your veterinarian may put local anesthetic in the navicular bursa or on the nerves that provide sensation to the back of the hoof. If the horse is sound after this anesthetic, chances are the pain is in the heel.

Radiographs are usually taken to get a better diagnosis of what structures are involved. If available, MRI or CT scanning can greatly improve what your veterinarian can see in the foot. There are multiple tiny ligaments and tendons in this area that can be damaged but not seen with radiographs alone; MRI can provide visualization of these structures.

Treatment

Treatment depends on what structures are involved and what type of conformation has predisposed the horse to the condition. For example, if the horse has under-run heels and a long toe, then the treatment should be directed toward shortening the toe and encouraging heel growth toward the rear, rather than forward. Imagine trying to walk around with flippers on. Your calf and heel gets painful.

Heel elevation with a shoe, pad or boot may be warranted as well. Some horses that have had long term heel pain will have contracted heels from not using that hoof as much as the hoof on other side. When viewed from the back the heels on the affected side are narrow and the hoof itself may be smaller and narrower than the other side. Treatment of these should be directed toward allowing the foot to spread out more and getting better support in the heel.

See the example of utilizing digital radiographs to help with trimming and shoe placement, above (hoof pastern axis was improved by almost 10 degrees). In this case the shoe could even be pulled back and the toe shortened more if the sole allowed. This sole was already too thin to do much more, but the horse improved dramatically just with trimming and shoeing alone.

Anti-inflammatory medications such as phenylbutazone are often needed to reduce the initial pain and inflammation. Depending on what structures are involved (soft tissues, bone, joint, etc.) the horse will probably need a period of rest, often several months if ligaments and tendons are damaged. Some veterinarians may recommend treating the navicular bursa or coffin joint with corticosteroids plus or minus hyaluronic acid.

Often, horses with hoof pain of any kind may benefit from chiropractic therapy because of the secondary compensation problems such as neck and back soreness. Chiropractic may actually improve some of the biomechanical problems that initially led to the heel pain.

Summary

Heel pain is a complex syndrome involving several structures that can be difficult to visualize without advanced diagnostic imaging. Overall, it is a conformational and/or biomechanical problem. It can be very painful and career-ending (horses carry 60% of their weight on the front feet). If the conformational problems can be addressed early on with corrective and therapeutic hoof trimming and/or shoeing, the horse can have a much longer, pain-free life.

Sleep Deprivation in Horses Part 2 of 2

Is your horse getting enough sleep?

by Dave Sauter, DVM

As noted in last month's article, sleep deprivation will occur in horses if they are either prevented from lying down or unwilling to do so. Unlike humans, horses take several days or even weeks to develop symptoms of sleep deprivation. Symptoms include:

Excessive daytime sleepiness
Collapsing episodes, especially during relaxing circumstances (e.g., during grooming, while resting in a standing position)
Unexplained wounds or scars, especially on the front of the front fetlocks and the front of the knee—these injuries are caused by the collapsing episodes

Long term videotaping can assist in the diagnosis. It can help document an absence of recumbent sleep patterns and unobserved collapsing episodes.

Sleep deprivation is not the same as narcolepsy. Narcolepsy in horses, as in people, is rare (although there is a familial narcolepsy documented in miniature horses). With narcolepsy there is a sudden onset of uncontrolled sleep, a “sleep attack,” with complete loss of muscle tone. Play and startle reflexes have been reported as triggering factors in narcoleptic horses.

As prey animals, feeling safe and secure is of paramount concern before horses will allow themselves to enter such a vulnerable state as REM sleep. The natural setting for sleep in horses occurs in established herds. Often the members of the herd will be in various stages of sleep. This ensures a “sentinel” that is relatively more alert is on guard for any potential threat. Since they only need about 30 minutes of REM sleep, herd mates take turns performing the sentinel duties so everyone gets their opportunity.

Causes of Equine Sleep Deprivation

There are many causes of sleep deprivation in horses. Dr. Joe Bertone, a veterinarian board certified in internal medicine, has published several papers on the topic. To help organize and facilitate the diagnosis and treatment of sleep deprivation, Dr. Bertone has divided the causes into three categories:

--Pain-related

There are three basic components necessary to get REM sleep: what it takes to lie down, comfort while lying down, and getting back up again. If there is pain related to one or more of these components and the horse repeatedly experiences the difficulty, eventually it will avoid the painful process altogether. Here are some examples:

1. The most common situation is some musculoskeletal problem or combination of problems such as arthritis or old injuries. This is especially the case in older horses whose bodies have suffered wear and tear over the years and are less able to compensate for their aches and pains.


2. Thoracic pain in a horse that has survived pleural pneumonia but has lingering adhesions in the chest cavity.


3. Abdominal pain from something such as an enterolith (mineral deposit in the large intestine).


4. Late term pregnancy making all three steps more difficult and uncomfortable.


5. Neurological disease—in this case, it may be the distress, inability and struggle associated with getting down and back up again that results in the sleep avoidance behavior.

--Environmental/situational

Any environmental or situational condition that compromises the sense of security and safeness necessary for proper sleep can cause sleep deprivation. Examples:

1. Prey issues—lone horses may feel unsafe on with no sentinel to watch out for them. Wildlife, loose dogs, etc., can contribute to this.


2. Hierarchy issues—horses on the bottom of the pecking order may constantly feel threatened by herd mates, especially bully horses. Horses on the top are also at risk if they are constantly on alert in less safe environments in efforts to protect the herd. Another example of this is when new horses are introduced.


3. Loss of a companion.


4. Rigorous show and travel schedule.


5. Other environmental issues, such as stabling conditions, mud, ice, weather, noise, and travel that interfere with the sense of familiarity, safety and comfort can also be causes of sleep deprivation or avoidance.

--Monotony-related

This pertains to a horse that spends long hours in a fairly relaxed and boring situation, such as on the cross ties. As with humans, horses need activity during their waking hours to promote quality sleep.

There is no standard treatment or medicine that can be prescribed to treat sleep deprivation. The solution, if there is one, lies in identifying the cause(s) and addressing them individually. Although they don’t need nearly as much as humans do, horses need their sleep to be healthy. If your horse shows symptoms of sleep deprivation or you have concerns, discuss them with your vet.

Sleep Deprivation in Horses, Part 1 of 2

Common sleep patterns and needs
by Dave Sauter, DVM

We all need our sleep to be healthy, and we need to be healthy to sleep. That is as true for horses as it is for us. In this two-part series we explore the subject of sleep in horses and what happens if they don’t get enough of it.

All of us sleep, usually every day. We know how it feels if we don’t get enough. Yet for all our experience, there is much about the subject of sleep that remains a mystery. Sleep has attracted the attention of medical minds since the days of Hippocrates in 400 B.C. It wasn’t until the 19th century, however, that science began to take a serious look at the subject. As our understanding of sleep has grown, so has our recognition of its importance to our health. In 1996 the American Medical Association recognized sleep medicine as a specialty. This subject has also received more attention in equine medicine in the last several years.

What is Sleep?
How is sleep different from other forms of unconsciousness, such as a coma? Sleep is a state of immobility with greatly reduced responsiveness. Unlike hibernation, sleep is rapidly reversible. It is possible to quickly wake up to a state of nearly complete mobility and mental alertness. During sleep there is unconscious sensory input and processing. Hence a crying baby may wake a worried parent while a thunderstorm might not. When sleep is prevented, there is an increased desire and need for it.

Sleep can be divided into two types, Rapid Eye Movement (REM) sleep and Non-REM (NREM) sleep. REM sleep is characterized by brain wave patterns, heart rate and respiratory rate similar to when awake, decreased muscle tone, and, as the name states, rapid eye movements. REM and NREM sleep have been identified in birds and all of the 60 – 70 terrestrial mammals that have had sleep studies. Marine mammals sleep with half of their brains at a time (and keep one eye open and one closed).

Amongst herbivores, the larger the species, the less time is spent sleeping. In general, carnivores sleep more than omnivores and omnivores more than herbivores. Animals that are born more immature tend to need more REM sleep. Here are a few examples (in hours of sleep needed per day):
• Cat - 12
• Dog - 10
• Human - 8
• Goat - 5
• Cow, elephant, sheep - 4
• Donkey and horse - 3
• Giraffe - 2

Sleep Patterns in Horses
Horses require much less sleep than their human counterparts, only three to five hours per day. Drowsiness and the equivalent to a human's lighter planes of sleep can be achieved while standing. Horses take on a characteristic stance when engaging in this level of sleep. Weight is supported on both front legs. On the hind limbs, one leg supports weight while the other is unloaded. Some speculate that this ensures one hind limb is in the “cocked and ready” position in the event a threat approaches while horses are resting. Sleep studies suggest that the hindquarters are pointed toward the greatest perceived threat (e.g., the stall door). This drowsy posture can progress into Slow Wave Sleep (SWS), equivalent to the deeper planes of sleep in people. Unlike people, horses can achieve SWS while on their feet. Their heads will characteristically drop to a lower level. They may, however, decide to lie down to continue their SWS in sternal recumbency (i.e., on their chests).

Recall that in REM sleep, muscles have greatly reduced tone. This is true for the horse as well. This means that for horses to enter REM sleep they must be recumbent (lying down). Generally, horses in REM sleep will lie flat out (lateral recumbency), but occasionally they will remain in sternal recumbency, bracing their chins on the ground passively as the poll drops when muscle tone decreases. Horses only require about 30 minutes per day of REM sleep, much less than people, who average about two hours per day. Outward features of REM sleep in horses include paddling, twitching, blinking, rapid eye movement, ear twitching and flaring of the nostrils.

Sleep deprivation will occur in horses if they are either prevented from lying down or unwilling to do so. Next month, we will look at the symptoms and specific causes of equine sleep deprivation, and how they relate to your horse's overall health.

Can I Get Some Bute?

Why some common medications require a prescription
R. Paul Schwab, DVM


Veterinarians get many requests each week for medications such as phenylbutazone (“bute”), trimethoprim/sulfa (TMS) pills, and others that require a doctor’s prescription. Many of these are used routinely for horses with minor and major ailments including injuries, wounds, respiratory infections, etc. A large percentage of horse owners and trainers are very familiar with their uses and side effects, but are frustrated when the veterinary office may not sell it to them without first seeing their horses.

Veterinary drugs are classified in different categories that determine how a particular product can be dispensed:

1. Over the Counter (OTC) drugs do not need a prescription from a veterinarian; products may be sold through catalogs, feed stores, and veterinary hospitals.

2. Prescription (Rx, Legend) drugs have the following statement: “Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian.” Prescription drugs may be distributed only by persons or firms authorized by state and local laws.

The FDA is the responsible party who puts individual medications into one of these categories. Usually they are classified based on the amount of information required so a product can safely be used in an individual animal.

Veterinarians usually dispense prescription drugs based on the need of an animal or group of animals that they are treating for a specific problem. There are times when we can dispense medications to owners or trainers for animals that we have not seen. We may recommend and dispense a prescription medication to an animal for a simple problem handled over the phone or for an ongoing issue on an animal treated previously. Veterinarians can only do this if they have a veterinarian-client-patient relationship (VCPR) with the person they are selling the medication to.

A VCPR exists if*:
1. The veterinarian has assumed the responsibility for making clinical judgments regarding the health of the animal and the need for medical treatment, and the client has agreed to follow the veterinarian’s instructions.

2. The veterinarian has sufficient knowledge of the animal to initiate at least a general or preliminary diagnosis of the medical condition of the animal. This means that the veterinarian has recently seen and is personally acquainted with the keeping and care of the animal by virtue of an examination of the animal or by medically appropriate and timely visits to the premises where the animal is kept.

3. The veterinarian is readily available for follow-up evaluation, or has arranged for emergency coverage in the event of adverse reactions or failure of the treatment regimen.

What Does All This Mean?
Basically, in order for a veterinarian to sell or prescribe a medication for an animal(s), he or she needs to have seen that animal or group of animals recently and know the client well enough to know the medication will be used properly and for those animals only. The actual time frame may vary between states or clinics, but realistically, an animal needs to have been seen within one year.

Online Pharmacies
How do online pharmacies fit into this picture? You can buy medications from online pharmacies if your veterinarian has faxed or called in a prescription to that pharmacy and as long as that pharmacy is certified through the National Association of Boards of Pharmacy. The pharmacy staff veterinarian cannot authorize a prescription without consent of a licensed attending veterinarian.

These rules and laws are meant to help protect the animal from misuse or misunderstanding of use of a particular medication. So on your next visit to the vet, if the receptionist or veterinarian doesn’t freely give out the bute or TMS tablets you wanted to pick up, there is a reason.

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*Taken from AVMA’s Guideline for Veterinary Prescription Drugs

Horse Identification

Why and how equine identification methods work
by Dave Sauter, DVM, photo by NWHS

Civilizations have been keeping birth records on their human populations since ancient times. In modern times, official documents used for personal identification include birth certificates, social security numbers, driver’s licenses and passports. Nowadays there is even a system for identifying all of our automobiles. There is no standard state or federal record keeping system for horses, yet there are numerous situations in which the identity of an individual horse is important.

Reasons for Identification
The most fundamental reason for individual identification of a horse is for proof of ownership. There are two basic parts to proof of ownership. One is that the horse is who you say it is; the other is that you are that individual’s owner. When it comes to unregistered horses, there is often a lack of any sort of documentation of either of these. Instead, we rely on a sort of honor system. But there are times when it is helpful to have something more, such as when horses are bought and sold. At a minimum there should be a bill of sale to document the change of ownership, along with a written description of the horse (age, sex, breed or type, color and physical description).

Although not very common, horses can be lost. Having a method of identification can be an enormous help in returning lost horses to their homes. Some forms of identification (e.g., branding) can also function as excellent deterrents to theft.

Federal and state governments have an interest in animal identification. The Department of Agriculture requires Interstate and International Health Certificates whenever livestock (that includes horses) travel to other states or governments. These records document the description of the animals, the owner, where they originate from and shipping destination. This system helps ensure diseased animals are not shipped and helps trace the movements of animals in the event of a disease outbreak.

Methods of Identification
Homemade: Something simple everyone can do, especially if you currently have no registration papers, bill of sale, or brand certificate, is to write down an accurate description, something similar to what would be found on a health certificate or registration papers. Include a set of at least four photographs, one from each side of the horse. Position the legs so all four are visible in each photograph. Include:
• Breed or breed type
• Sex
• Color
• Date or approximate year of birth
• Description of all white markings (head, legs and body)
• Whorls (or cowlicks) on face
• Permanent acquired marks (scars, lumps, bumps, tumors, brands, tattoos, etc.)

Registration papers: Breed registration papers provide excellent individual identification and ownership documentation. Different breed organizations define the requirements, administer the program and provide a central database of all records. Each registered horse will have its own number, description, pedigree record, date of birth, owner’s name(s), etc.

Tattoo: This method is used by the Thoroughbred and Quarter Horse racing industries. The numbers and letters used correspond to the horse’s registration number. This permanent mark placed on the inside of the upper lip provides race officials with a quick and easy means to verify a horse’s identity. The disadvantage is that not all lip tattoos come out well, and they can be difficult to read. Also, over time some of the symbols can fade.

Brands: The history of branding helps illustrate how long animal identification has been important. Hieroglyphic paintings depict brands applied to animals, so we know the technique dates back to ancient Egypt, at least. We know the ancient Greeks and Romans used branding. Cortez is credited with bringing the custom of branding to the New World in the 1500s. American ranchers eventually simplified brand designs in favor of patterns that were easier to remember and more difficult to alter.

The visible external mark of the brand can facilitate recovery of a lost or stolen horse, and has the added benefit of theft protection as horse thieves are less likely to target branded horses.

There are two basic types of branding techniques, hot branding and freeze branding. Hair actually has two types of follicles: the deeper growth follicle, which generates the shaft of the hair, and the shallower pigment follicle, which produces the color in the hair. Hot branding results in a deep burn that destroys both follicles. The result is a “bald” brand. Freeze branding allows greater control. The duration the freeze brand is applied to the skin determines the depth of the freeze effect. With a shorter duration only the pigment follicle will be destroyed. After the skin has healed, unpigmented hair grows back, a process that takes a few months. The white hairs show the design of the brand nicely when contrasted with red, brown or black hairs. If the horse is white or grey, the “bald” brand is preferred so it is more easily seen. If this is the goal, the freeze brand is applied for a longer duration to destroy the deeper growth follicle.

Mustangs adopted through the BLM program and some Arabians use freeze brands. Utilizing a series of symbols that coincide with the horse’s registration number, the brand is applied to the crest of the neck (left side for mustangs and right side for Arabians). Racing Standardbreds also utilize a freeze brand on the crest of the right side of the neck that uses numbers and letters to represent the horse’s identity.

Private brand designs have to be approved and registered with the state. These designs indicate the mark of the brand's owner. This brand does not provide identification of a specific horse. What it says to the world is that any horse carrying that brand is currently or was previously owned by the owner of the brand. Similarly, some warmblood breed registries use a brand representing the breed, indicating the horse passed the necessary inspections to earn the brand.

Microchip: With the microchip, animal identification has finally entered the 21st century. Microchips are designed to be implanted into animals as a form of individual permanent identification. A radio frequency identification device (RFID) is about the size of a large grain of rice. It has no internal power source. When triggered by a compatible scanning device, it sends a coded signal the scanner reads, matching the recorded identity of the animal. For horses, the usual location for placement of the chip is one inch below the crest of the neck, left side, midway between the poll and the withers.

Some breeds require microchipping as part of the registration process. The microchip is virtually impossible to alter, and it represents a cost effective, reliable individual identification technology that can be traced back to the current owner through nationally maintained databases.

Identification in the Real World
In 1994, Louisiana began a program requiring all horses to have some form of permanent identification: a brand, tattoo or microchip. 70-80% of horse owners chose to microchip. After Hurricane Katrina struck in 2005 and hundreds of horses were displaced from their farms, rescuers using scanners over the customary left side of the neck were able to quickly match horses with their owners. The success in terms of percentage of horses returned to their proper homes and the speed with which it was accomplished was much greater than in comparable disasters. This is at least one example of where the technology really worked.

Health Concerns of the Boarded Horse

What to be aware of to maintain optimal health for your boarded horse
by R. Paul Schwab, DVM

Horses at a boarding facility have a unique set of circumstances that warrant extra veterinary consideration. They are typically around many other horses from different backgrounds going in and out of the facility to shows and events, potentially to other states and/or countries. Basically, boarded horses are exposed to diseases they may not have had exposure to otherwise. Other concerns that should be addressed in regards to boarding include nutrition, turnout, and basic health care, which may or may not be the horse owner’s responsibility.

Preventative Measures
Vaccinations are an important part of disease prevention for any horse; this is especially true of the boarded horse. All horses, regardless of environment and use, should be vaccinated for West Nile Disease and tetanus once per year. Horses that have limited exposure to other horses on the trails or minimal showing should be vaccinated for Equine Influenza and Rhinopneumonitis annually as well. Boarded horses or other horses that may be around multiple horses that travel all over the country often should get the Equine Influenza and Rhinopneumonitis at least every six months. The area where your horse lives will determine what other vaccines may be needed (e.g., rabies, Potomac Horse Fever, etc.) Also, if a boarding facility has had problems with Strangles, it might be wise to vaccinate for Strangles before arrival.

Good general health is important for any horse, obviously. Healthy horses can fight off bacteria and viruses that they are exposed to with their own natural immunity. Regular veterinary check-ups and good hoof and dental care can be a valuable investment in your horse’s overall health and immunity.

Nutrition is probably the most important factor in the healthy boarded horse. Who is responsible for feeding your horse? How many people feed your horse? Does your horse need a special diet, and who sees that he gets that diet? Most boarding facilities do an incredible job of taking care of multiple horses and diets at one time, but your horse may have specific dietary restrictions that should be addressed and monitored.

Maintaining Health
Parasites are always an issue but may be more of a problem at a boarding facility, depending on the housing, turnout, and number of animals present.

One advantage to keeping horses in stalls is that they are not a good environment for parasites. They are usually cleaned daily and the urine destroys many of the parasite eggs. If the hay is kept mostly off the ground, the horses don’t graze in the stall. If horses at the boarding facility are grazed together or in the same fields or paddocks, parasites are more likely to spread. Frequent fecal checks can help determine the amount of deworming appropriate for the individual horse and situation.

While we are on the subject of grazing and turnout, it’s important to remember what a horse is supposed to do in the wild: they graze most of the day over wide expanses, running, socializing, and generally being horses. Stables are not the natural environment for horses, so we need to provide them with enough stimulation to fill that void. Frequent exercise, turnout if possible, and socializing to keep their minds and bodies working can help. Boredom in horses can result in vices such as wood chewing, cribbing, and stall weaving, not to mention medical problems such as stomach ulcers and colic. Feed them multiple times a day if they don’t have turnout, and give them jobs. Horses are working animals and need something to do.

It’s our responsibility to take care of the horses we own, even if they are not at home with us every day. Considering health along with other factors when choosing a boarding facility can save you time and money down the road.

Understanding Equine Reportable Diseases

Learn the facts behind three equine diseases in recent news

by Dave Sauter, DVM

Today’s article will provide updates on three infectious diseases that have been in the news in recent months. Although these diseases are quite different, they have three important similarities: all three are diseases of horses, all three are “reportable diseases,” and all three are in the news.

Reportable Diseases

Many diseases can have devastating affects on public health, animal health, agriculture, industry and the economy. A recent example is the H1N1 human and swine influenza virus. Other examples that have gained much public attention in recent years include toxigenic E. coli, Mad Cow Disease and Foot and Mouth Disease.

On a global scale, the agency that tracks human reportable diseases is the World Health Organization (WHO). For animal disease, it is the World Organization for Animal Health (OIE, or Office International des Epizooties). In the U.S., the tradition traces back to at least 1878, when the CDC began tracking cholera, small pox, plague and yellow fever. Currently, much of the tracking responsibility falls onto state health agencies.

The lists of human and animal diseases these agencies track are long. Veterinarians, physicians, laboratories and other health care providers are required by law to report to appropriate government agencies whenever a reportable disease is encountered. Having a central reporting system in place enables rapid disease control measures to be implemented to minimize the spread of these diseases and their impact on human and animal health and the economy.

West Nile Virus (WNV)

Washington State topped the nation last year in the number of horses that tested positive for the WNV. According to Dr. Leonard Eldridge of the Washington Department of Agriculture, nearly all of the 41 positive horses were unvaccinated. Evidently, this year the WNV is making an early appearance. The state has been monitoring the mosquito population for the presence of the virus because it is the first signal that the virus is present. The Department of Health reported on June 3rd that it had detected the virus in mosquitoes collected in Yakima County. This represents one of the earliest detections of the virus since monitoring started in 2001.

The WNV was first identified in 1937 in Uganda and is established in Africa, West Asia, Europe and the Middle East. It made its first appearance in the U.S. in 1999 when it struck in the New York City area, resulting in 11 human deaths. Various species of birds serve as the natural host of the virus, which is transmitted by mosquitoes. Humans and horses are considered “dead end” hosts of the virus – we can get infected, but the disease does not spread from us, not even to uninfected mosquitoes that bite us. Horses are particularly susceptible to the infection. Although many horses that are infected do not show any symptoms, those that do get very sick, with a 30% or more mortality rate. Of the cases that become unable to stand due to the severe neurologic impairment, 60% die.

One of the reasons WNV is on the list of reportable diseases is the impact it can have on the equine industry. At its peak in 2002, over 15,000 horses that we know of in the U.S. died from WNV. Another reason it is important is because the incidence of the disease in the horse population gives human health care agencies a better indication of the incidence of the virus in the community. This assists them in making decisions concerning disease control measures, such as mosquito control.

At least three vaccines are available for WNV in the horse. They are all safe and reasonably effective at preventing WNV.

Contagious Equine Metritis (CEM)

CEM is a venereally transmissible disease of horses. There is no evidence to suggest that CEM affects people. The reason for its importance is because it is very contagious and could have devastating affects on the equine breeding industry.

The first case of CEM was diagnosed in 1977 in England. The following year it showed up in central Kentucky and in 1979 it was found in Missouri. The disease was eradicated from both states and no new cases were detected until 2006, when two post-quarantine imported Wisconsin stallions tested positive. The disease was rapidly contained again. Then, in December 2008, a central Kentucky stallion tested positive. Further investigation revealed that this outbreak spread far and wide prior to detection. To date, records indicate that at least 971 horses in 48 states have been exposed to the disease (Rhode Island and Hawaii are the only two states without at least one exposed horse). As of June 2009, the USDA reported that of the 971 exposed horses, 21 stallions and 5 mares have been diagnosed positive for CEM.

CEM is caused by a bacteria that is transmitted directly by intercourse but also indirectly through artificial insemination and through contact with contaminated surfaces, e.g., instruments, semen collection equipment, etc. Although acutely infected mares will develop a vulvar discharge, stallions and chronically infected mares do not have outward symptoms and can be the source of continued transmission of the disease. Since stallions do not have any symptoms and they can potentially breed tremendous numbers of mares, rapid dissemination can occur.

Vesicular Stomatitis (VS)

Vesicular Stomatitis occurs sporadically in the United States, principally in the western states. The disease causes blister-like lesions on the muzzle, tongue, teats and above the hooves of susceptible livestock, including horses. In fact, horses are often the first species of livestock to be confirmed positive in an area where the virus is active. Although the mortality rate is low, the morbidity rate is high. The virus spreads fast and furiously, commonly affecting upwards of 90% of the herd. Cattle and pigs also can get VS. The problem with VS in these species is that the lesions look very similar to the much more serious Foot and Mouth Disease (FMD). FMD is one of the most dreaded diseases of livestock owners because it is highly contagious, spreads rapidly over long distances, and causes severe economic losses. For example, a FMD outbreak in 2001 in the United Kingdom resulted in a reported 3.9 million animals, most of them healthy, being destroyed in order to contain and eradicate the disease. Compensation to farmers of the slaughtered animals cost the government more than one billion dollars. The last case of FMD in the U.S. was in 1929.

VS can cause serious losses also, but not to the level of devastation FMD would cause. Whenever VS does become active, it causes huge headaches because FMD must be considered a possibility until proven otherwise. Testing must be completed quickly because of the speed at which FMD spreads. Horses are not susceptible to FMD, so they can be helpful in the investigation.

According to Texas State Veterinarian, there is a current VS outbreak in that state involving just one horse. Prior to that, the most recent outbreak was in 2006 and only involved the state of Wyoming, where 17 horses and a dozen cattle on 13 premises were affected. In 2005, there was a VS outbreak involving livestock on at least 445 premises in nine states. To date, Washington State has never had a case of VS. Hopefully, prompt notification and containment of outbreaks in other states will keep it that way.

The Thin Horse

Common causes of underweight horses

by R. Paul Schwab, DVM

One of the most common reasons for veterinary farm visits is to examine horses that are thin. This is especially true the last couple of years with the increase in animal welfare cases, abandoned horses, and the recession. Diagnosing reasons for weight loss can be challenging, especially if the horse’s history is unknown (e.g., how much they are eating, what shots they have had, etc.).

I find it easier to divide reasons for weight loss into four categories:

1. Nutrition

2. Teeth

3. Parasites

4. Everything Else

The first three are the most common reasons for weight loss and easier to diagnose and treat. The “everything else” category often needs the assistance of lab work, ultrasound, or trial and error.

Nutrition

Basically, horses need forage and a lot of it. A horse will consume approximately two percent of its body weight per day in dry matter, most of which should be forage (hay or pasture). This translates into about 20+ pounds of hay/grass for a 1000-pound horse. Weigh your hay periodically. Flakes of hay are not a good indicator of how much hay a horse is getting unless you know how much each flake weighs. Often, weight gain is as simple as feeding more food. Grain can be used to supplement the diet but should never be more than fifty percent of the ration unless it is a complete-type feed. Complete feeds have forage products added to them such as alfalfa, beet pulp, etc., that make them safer to feed at higher amounts. Other ingredients that are often used to help supplement forage include beet pulp, soy hulls, and fats such as rice bran and canola or corn oil.

Don’t forget about quality of feed. Forage can be extremely variable in quality depending on the time of year, type of grass, when it was cut, how it was stored, and other factors. Horses on poor quality hay might maintain their weight but probably won’t look very good and certainly won’t perform as well. If you purchase large amounts of hay at a time, or put up your own hay, consider using a forage testing service. The expense of the analysis is minor compared to the expense of treating sick or poorly faring horses.

Teeth

If your horse can’t chew properly, it can’t maintain weight. Dental problems can be as simple as sharp edges on the molars or more complicated, such as jaw alignment issues. Advances in nutrition, parasite control, and preventative medicine have greatly improved life expectancy in horses. Their teeth, however, still only last so long. By about age 28-32, many horses start losing teeth. With regular dental care, we can keep these horses more comfortable and hopefully lengthen the time that they have useful teeth. Eventually, if horses outlive their teeth, special feed that is easier to chew will be required, such as a complete senior feed or hay pellets.

Older horses aren’t the only ones with dental issues. Over the years, we have bred horses for many purposes, including good leg conformation, speed, strength, and yes, color, but not much emphasis has been placed on good teeth. Starting early with dental exams can help identify potential issues before they become problems. Alignment issues and abnormal wear patterns are much easier to deal with early on. Because they continue to erupt throughout life, uneven wear can lead to future problems such as wave mouth, which is impossible to correct if severe enough. Regular dental care may even save money on feed bills, due to better feed conversion and less grain dropping on the ground.

Parasites

Each parasite has its own way of bringing down the health of the horse. Some parasites feed on the blood; some damage the intestinal lining, preventing normal absorption of nutrients; others migrate through the lungs or other organs, destroying normal tissue as they go. In any case, the horse is less healthy and less productive when it has parasites.

The good news is that most parasite infestations are easy to diagnose. A simple fecal floatation test can detect most internal parasites, and most of the external parasites such as lice and ticks are seen with the naked eye. What to do about these can be more complicated. Treatment and prevention is best discussed with your veterinarian.

Everything Else

Infectious disease, cancer, metabolic abnormalities, ingestion of toxic plants: these are just a few entries on the long list of problems that can cause weight loss in horses. Diagnosis starts with a basic physical exam and complete history. More complicated cases may require blood work, cultures, or other laboratory tests.

With any weight loss case, an accurate history is imperative. Often, the answer is found before the horse is even seen. Keep accurate weights on the amount of hay and grain that is fed daily. Regular visits by your veterinarian can help with early detection of dental and health problems. And let me say again: Weigh your feed! Coffee cans are not a measure of weight!

Medication Safety

Handle and store your horse's medications safely

by Dave Sauter, DVM

Previous articles have discussed how to administer medications to horses, whether injectable, oral or topical. This month, I'd like to focus on proper handling of medications to ensure the stability, safety and effectiveness of the products.

Temperature

Many medications need to be stored within specific temperature ranges. Temperatures outside these ranges can alter the chemical nature and stability of the components. For example, vaccines are very sensitive to storage temperatures. Freezing can cause some vaccines to lose their effectiveness and become much more reactive--in other words, much more likely to cause heat, swelling and pain at the injection site.

Another example is penicillin. The most common type of penicillin used in horses is Procaine Penicillin G, which is supposed to be refrigerated but not frozen. There are different types of penicillin injection reactions, and all of them are pretty scary. One of the reactions (disorientation, fear response, seizure and collapse) is thought to be related to the procaine. The procaine in Procaine Penicillin G is bound to another chemical. Storage at room temperature has been shown to result in more release of the procaine from this other chemical and to increase the chance of this reaction.

To keep medications stable, safe and effective until their expiration dates, follow label recommendations for storage temperatures. If refrigeration is required, do not store medications in the door of the fridge, where temperatures fluctuate more; keep them near the center.

Sunlight

Many medications are sensitive to sunlight. For example, sunlight inactivates ReguMate. Medications in dark-colored bottles often are light sensitive (e.g., Acepromazine). Direct sunlight can be particularly damaging to vaccines, resulting in less immunological effect (which is the goal of vaccination in the first place) and greater injection site reaction (which we all strive to prevent).

Transport

It is important to maintain proper storage conditions during the transport of medications. If you have a long drive from the veterinary clinic to the farm, putting medications on the dash where heat and sunlight can damage them is not a good plan. Use a small cooler to keep your refrigerated products cool, but do not place products like vaccines directly onto an ice block. Similar precautions should be taken when necessary to protect products from direct sunlight and extreme temperatures when they are taken out of storage for use in the horse.

Cleanliness

This is particularly critical with injectable products. Products such as Procaine Penicillin G, Naxcel or Banamine are in multi-dose vials. Each time the needle enters the bottle there is the potential for contamination. Injection of a contaminated product into the horse can result in cellulitis, deep abscesses, and other serious complications like tetanus. Store these products in a clean environment. Clean the surface of the rubber injection cap, if it is dirty, with gauze soaked in 70% isopropyl alcohol (rubbing alcohol) before inserting the needle. Always use a new needle and keep the cap on it. Never touch the needle or allow it to touch anything but the medicine and the horse it is intended for.

Dosage

Follow the label directions as closely as possible.

·

Make sure to prepare and deliver the correct amount at the proper interval. Always double and triple check that the prescribed amount of medication is prepared. For instance, it is easy to overdose an oral medication in a multidose cartridge, such as Bute, if the dial is not set properly.

·

Do what is safe and necessary to administer the medication to the horse. If the medication ends up on the wall or the floor instead of in the horse, then the horse is not going to maintain therapeutic levels in its body.

· Follow the instructions on dosing interval. Shortening the interval can result in toxicity. The medication will drop below therapeutic levels if the interval is increased. This is especially problematic with antibiotics because it will cause drug resistance. Once a day means every 24 hours, twice a day every 12 hours, three times a day every 8 hours, four times a day every 6 hours, etc.

Personal Safety

Many of the medications we use in horses are powerful drugs that can affect us. I am still amazed when I give less than one cc of sedative to a one ton draft horse and see the powerful effect that tiny little bit has on such a huge animal. During the preparation or administration of medication, small amounts can get on our hands. Rubbing one’s eyes or mouth can inadvertently result in absorption of these drugs into our own bodies. Ventipulmin syrup can cause your heart to race. Atropine eye ointment can cause your pupils to dilate. ReguMate can absorb through the skin and affect the female reproductive system (and probably the male, also). Take precautions with all medications. Use gloves when so instructed and avoid rubbing your eyes or touching your face until you have washed your hands. Always wash your hands after handling any medications.

Proper Disposal

Children and other animals, often dogs, are at the highest risk of getting into contact with used oral medication cartridges, tubes of topical medications, used vials, etc. Children and pets can be very curious and very fast. One example I recall is that of a border collie that licked the end of a dewormer cartridge that had been dropped on the floor after use. There was a little paste on the end, enough to cause neurotoxicity. Fortunately, the dog survived. The owner still lets the dog follow him around the barn, but he doesn’t throw used cartridges on the floor anymore.

Needles deserve special mention. The EPA estimates that eight million people use more than three billion sharps (needles, syringes and lancets) per year in the United States. Leftover needles not only carry the risk of pain from accidental puncture, but also the risk of disease. In many counties and cities, it is against the law to dispose of used needles in garbage cans or recycling bins. Check with your county Department of Health for rules and guidelines for the proper disposal of used needles in your area. Here are some websites with more useful information:

· Coalition for Safety Community Needle Disposal - www.safeneedledisposal.org

· Centers for Disease Control - www.cdc.gov/needledisposal

· Whatcom County Health Department - www.co.whatcom.wa.us/health

· www.sharpsdisposal.com

· www.stericycle.com/mailback.html

General Wound Care

Get familiar with basic equine wound care before you hit the trails and shows 

by R. Paul Schwab, DVM 

Everybody has a wound spray, ointment, powder, or miracle paint to sell to treat wounds. In fact, the more strange the product, the more people think it works (especially if it’s blue, smells like turpentine, and was made in a jar in someone’s garage). Do these products work? Maybe. Who says? The neighbor, the vet, the feed store? Probably not the FDA. What is the best way to treat a wound? Is there a best way? In this article I hope to cover some basic wound care concepts. 

When to Call the Vet

Obviously, anything that looks like it requires suturing (i.e., gaping wounds, visible bone, excessive bleeding, etc.), has loss of function or excessive swelling should be seen by a veterinarian. Wounds that require sutures should be looked at within 12 hours to have the best outcome. Also, horses that are acting sick or running a fever (temperature greater than 101 degrees) should be seen. Other cases that may warrant veterinary attention are wounds that are slow to heal or have excessive granulation tissue, known commonly as proud flesh.

What Can You Do?

General wound cleaning and irrigation goes a long way. One of the first things we like to do, especially on a deep wound, is clip the hair around the wound to keep it from matting up with serum, blood and other debris. Clipping all wounds is a good idea because it often reveals a much larger wound than was seen without clipping. Gentle scrubbing with warm water and a mild soap such as Ivory liquid soap is helpful for removing debris. Povidone-iodine scrubs are excellent for cleaning and disinfecting the skin, but might be a bit too strong for inside a deep wound. Please, no peroxide! Hydrogen peroxide damages healthy tissue.

Wound irrigation is best done with saline solution. You can buy bags or bottles of sterile saline solution from your veterinarian (not a bad thing to have in a first aid kit). You can also make your own saline solution by adding two teaspoons of salt to one liter of water. Obviously, the cleaner the water is, the better. For small wounds, a 35-60cc syringe fitted with an 18 gauge needle works well to spray the saline over the wound. (Don’t inject the wound, spray it...yes, it has happened.)  Clean spray bottles also work well as saline wound irrigators. For larger wounds, a garden sprayer used to spray weeds (a new one, or at least a really clean one) makes an excellent large volume irrigator, as well as a good giant water pick for your horse’s mouth.

After the wound is thoroughly cleaned, it should be bandaged if possible. Keeping a wound covered helps keep the skin supple and elastic. Wounds that are not covered can be treated with triple antibiotic ointment to help with infection and to keep the skin edges soft. 

Special Considerations

Puncture wounds can be especially problematic. They appear small on the surface but often have deep pockets under the skin that can become infected. They will look fine for 24 hours or so, and then swell up with infection under the skin. These wounds typically need to be opened at the bottom to allow drainage.

Tetanus should be a consideration with any wound. If the horse has not had a tetanus vaccination within six months, it should get a booster.

Healing wounds should be monitored carefully for proud flesh. When a deep wound is healing, it fills with granulation tissue. This is the pink, lumpy tissue that quickly fills in the gap between the separated skin edges. The skin then slowly contracts over this granulation tissue until it is healed. Occasionally the granulation tissue keeps growing higher than the skin edges, preventing the skin from coming together. We call this "exuberant granulation tissue" or "proud flesh." Lower leg wounds in horses are especially prone to proud flesh formation because of poor blood perfusion and high motion. There are numerous ointments that claim to prevent proud flesh formation, but once it has developed, it has to be trimmed off to the level of the skin. You should get your veterinarian involved at this point; it can be dangerous, and granulation tissue bleeds heavily when cut.

In general, wound care is basic. Keep it clean, flush with saline, and monitor the whole horse (i.e., temperature, attitude, swelling, etc.). Worry more about what not to put on a wound, rather than what to put on it. If you wouldn’t put it on your own wound, don’t put it on your horse’s wound. Above all, keep in touch with your veterinarian regarding wounds on your horse. Every horse is different, and every wound is different. 

Pigeon Fever

A look at the forms and symptoms of an uncommon but serious infection

by Dave Sauter, DVM

Other than their name, pigeons have nothing to do with Pigeon Fever, a highly contagious disease of horses. Pigeon Fever has been considered endemic to California, but in recent years the incidence has been increasing in other western states such as Colorado, Wyoming, Montana, Idaho and Washington. It has also increased in southern states such as Kentucky.

Pigeon Fever is caused by bacteria that live in the soil and are found worldwide. The bacterium that causes the disease has an impressive name, especially useful for those who enjoy equine trivial pursuits: with two 7-syllable words, Corynebacterium pseudotuberculosis is a mouthful. 

The bacterium prefers dry, cooler environmental conditions. Although it can occur any time of the year, it is most prevalent in early fall. The bacteria gain access into the horse’s body through breaks in the skin, through small wounds on the body or through mucous membranes (e.g., the gums). Although not yet proven, many experts believe insects such as the housefly and horn fly play a role in transmission, literally carrying the bacteria from one horse to the next. There is no vaccine for the disease.

After invading through the skin or mucous membranes, it can take weeks for Pigeon Fever to incubate before clinical signs of disease develop. The bacteria spreads locally (i.e., wherever it gains access) and via lymphatics (vessels that connect lymph nodes together). Early in the course of the disease, symptoms can be vague and non-specific, such as fever, depression, weight loss and lameness. There are three principle forms the disease can take in the horse:

1. External Abscesses

This is the most common form of the infection in the United States. Abscesses can range from very small to deep, massive abscesses containing quarts of tan colored malodorous pus. They can occur anywhere in the body, but one of the most common areas is in the pectoral muscles. The resulting greatly enlarged pectoral area reminded someone of pigeon breasts, hence the name "Pigeon Fever." There are many other names for this form of the disease, including Pigeon Pox, Dryland Distemper, Dryland Strangles, and Breastbone Fever. 

Other common areas for the abscesses to form include the sheath, the mammary glands, under the belly and between the hind legs. When lesions develop on the ventral midline, they tend to form large, painful plaques of edema with multiple draining tracts (similar to what happens on the legs with Ulcerative Lymphangitis, described below) rather than the large pus abscesses seen in the pectoral muscles. Horses with the external abscess form have a good prognosis for full recovery.

Treatment centers on establishing good drainage. Poultices and hot packs can encourage superficial abscesses to open. The deeper abscesses and many of the superficial ones require surgical lancing to establish drainage. Ultrasound can be helpful in locating and directing the veterinarian’s scalpel to the center of these deeper abscesses. Disinfectants can be used to flush out the opened abscesses. Non steroidal anti-inflammatory medication such as Bute, Banamine or Equioxx might be indicated to help manage pain and fever. Antibiotic therapy is controversial. 

Although humans generally don’t get the disease, we unfortunately can carry it in the form of pus and other discharge from infected to uninfected horses. Other animals, including insects, can also act as transmitters of the disease. Affected horses should be isolated to try to contain this highly contagious disease. Everything should be kept separate (clothing, feed tubs, water buckets, water hose, barn equipment, etc.) to maintain biosecurity. 

2. Internal Abscesses

In some cases, the bacteria can penetrate beyond the region of the body where they first gain access and spread deeper into the horse’s insides, reaching into the thoracic and/or abdominal cavity. Internal lymph nodes and organs can develop abscesses. This dissemination into the body poses far greater risk of loss of life. 

Because these abscesses are out of sight, diagnosis is more elusive. In addition to fever, weight loss, and depression, other symptoms might be present, reflecting the organ system affected (e.g., nasal discharge for pulmonary, colic for abdominal, bloody urine for kidney, ventral edema for liver). Since drainage might be impossible to establish, long term antibiotic therapy generally is indicated, from one to six months. Mortality rate from this rarer form of the disease is much higher, over 40% in some reports. 

3. Ulcerative Lymphangitis

In this form of the disease, the bacteria gain a foothold in the lower limbs and eventually make their way into the lymphatics of the legs, most often the hind limbs below the hocks. As the bacteria spreads up the lymphatic vessels, chains of nodules appear on the limbs that ultimately abscess, ulcerate and drain. New lesions develop as older ones heal. Commonly, the limb becomes swollen and painful. Damage to the limb can cause permanent thickening, disfigurement and debilitation. 

In Europe and other parts of the world, Ulcerative Lymphangitis is the most common form of Corynebacterium pseudotuberculosis infection. Treatment includes long term use of high levels of penicillin. Note that other bacteria are capable of causing similar symptoms. Culture is necessary to confirm that Corynebacterium pseudotuberculosis is the culprit.

Animals at Risk

It is important to mention that ruminants are also susceptible to Corynebacterium pseudotuberculosis infection. Small ruminants, such as sheep and goats, are affected by a different subtype that does not affect horses. In sheep and goats, it is referred to as Caseous Lymphandenitis, more commonly known as Cheesy Gland, Lympho or Thin Ewe Syndrome. This highly contagious disease can cause significant economic losses from culling, carcass condemnation, etc. 

Cattle are susceptible to both sub-types of Corynebacterium pseudotuberculosis infection, the equine form and the small ruminant form, but are more likely to have the small ruminant sub-type. Laboratory testing can be done to identify which sub-type is present.

Although fairly uncommon, Pigeon Fever is a disease of growing concern. An awareness of what it is and the symptoms of the various forms can help to expedite its identification and containment if and when it shows up. 

What to do About Worms

Resistance to dewormers is increasing. How does a horse owner cope?

by R. Paul Schwab, DVM

If you haven’t heard already, I’ll break the bad news: we are already starting to see resistance to our current dewormers for horses. The worse news is that there are no new dewormers due to come out anytime soon. What does this mean? We need to utilize other methods of parasite control besides just giving dewormers every eight weeks. 

Dewormer resistance is not a new problem, especially on the East Coast. There has been resistance to most dewormers in goats and sheep for several years, but more recently it has become an issue in the horse population. We are just starting to see some of this resistance here in the Northwest now.

Without going into too much detail, resistance has probably developed over the years from our various rotational deworming strategies. Slow rotation, or using one product at regular intervals, without monitoring by checking fecal egg counts may allow resistant worm populations to dominate the pasture without being killed. Fast rotation schedules, or rotation of different products at regular intervals, may be selecting for resistance in all the classes used in the rotation if not monitored with fecal egg counts. 

What Can We Do? 

First of all, remember how horses actually pick up worms: the worm eggs and larvae live in the horses’ manure or the grass and ground just around the manure pile. If the horse grazes on pasture contaminated with these parasites (we are talking thousands of eggs in one manure pile), they will eat the eggs or larvae. These eggs or larvae then go through several stages of development within the horse and turn into adult worms that lay more eggs in the manure to contaminate your pasture. Removal of this manure is one strategy to reduce pasture contamination. 

What about harrowing? Remember, the worms stay within the manure pat. If you spread it around, you are actually spreading the larvae and eggs around the whole pasture instead of containing them in the manure pile. If you are not removing manure, you are better off leaving the “islands” of manure pats because usually—though not always—horses will avoid eating around the manure. Harrowing will help only if the ambient temperature is above 85˚, sunny, and the pasture can have no animals on it for at least four weeks (two months or more would be better).

Other practices that may help with reducing pasture burden include grazing on fields used recently for hay and rotating pastures with other livestock species (cattle, sheep, etc.).

Multiple-Horse Areas

We have always treated herds as a whole. If you deworm one, you assume they all have the same exposure and deworm everyone at the same time. We may need to rethink our strategies and identify individual animals that have more susceptibility to parasites. Geriatric and young horses, in general, are more prone to parasite infestation, but there also adult horses that may shed more worms and have less immunity to fight off parasite burdens. Using fecal sample monitoring, we can try to identify these animals and utilize that information to determine how often to deworm individual animals that shed more eggs into the environment.

Monitoring Egg Counts

Another way to utilize fecal egg counts is to monitor the effectiveness of individual deworming medications on the parasites on your farm. This is done by having a fecal test done the day that you deworm your horse. A follow-up fecal sample should then be taken ten to fourteen days after deworming. The formula for reduction is as follows:

[(Pre-Treatment Eggs/gram feces – Post-treatment Eggs/gram) / Pre-Tx EPG X 100]

Numbers above 90% indicate that the product is efficacious, and numbers below 80% indicate resistance. Numbers between 80-90% are questionable. This formula is a good tool but was developed with other species, not horses, so it should not be a gold standard. Further research may adjust this formula in the future, but for now it is very helpful to give you a general idea.

This is a very hot topic right now and much is still to be learned. As equine veterinarians and horse owners, we are in for a challenge over the next few years to get our arms around this issue. We have all trained ourselves to follow a schedule that until now has been the most consistent way to keep horses healthy and free of parasites. My advice is to sit down with your veterinarian to discuss a plan for parasite control for your individual farm situation. Utilize your veterinarian’s lab to assess your horses’ parasite load. You may actually find that your horses need to be dewormed far less often than you thought. 

AAEP Convention Highlights

A review of the 54th annual AAEP convention

by Dave Sauter, DVM, Kulshan Veterinary Hospital

The American Association of Equine Practitioners (AAEP) is a non-profit organization for equine veterinarians.  Founded in 1954 in the basement of a Louisville, Kentucky hotel with eleven charter members, the AAEP has expanded to over 9,000 veterinarian and student members in 64 countries.  The mission of the AAEP is to protect the health and welfare of the horse through equine research, public education programs, involvement with animal welfare affairs and ethics, and professional development programs for its members.  

2008 Convention Highlights

This year over 3200 veterinarians, students and veterinary technicians from around the globe gathered in San Diego, California from December 6-10 for the annual AAEP convention.  Total attendance exceeded 6500, representing the third-largest turnout in the convention's history.  Over 100 scientific papers were presented along with a huge selection of less formal “Table Topic” meetings on myriad subjects including lameness, an in-depth focus on laminitis, neurology, reproduction, dentistry, internal medicine, imaging, neonatology, emergency care at equine events and more.  

The “Kester News Hour,” designed to present topics either too recent or too brief to be included in the regular meeting, was one of the highlights. The late General Wayne “Sage” Kester, a native of Nebraska, helped form the AAEP in 1954 and was instrumental in forming the American Horse Council and numerous specialty groups within veterinary medicine.  Dr. Kester was an avid horseman who remarked at age 90 that little had changed for him as he got older except life insurance salesman didn’t pursue him anymore and he no longer purchased green bananas.  

Another highlight was the Frank Milne State of the Art lecture. This year’s speaker was Dr. Stephen Reed, a 1976 graduate of The Ohio State University who is considered an expert in the field of equine neurology.  He is the author of over 150 published articles, editor of Equine Internal Medicine (a textbook for veterinarians) and co-editor of the book Equine Neurology.  He lectured on many aspects of equine neurology, including the neurological examination of the horse, wobblers syndrome, equine protozoal myelitis (EPM), and herpes (Rhino).  Dr. Reed reviewed many advances in equine neurological diagnostics and treatments that are helping horses survive, commenting that “neurological disease is no longer a euphemism for necropsy.”

Scholarships and Charity

The AAEP Foundation is the charitable arm of the AAEP, founded in 1994 to unite individuals and organizations dedicated to improving horse health and well being.  The foundation supports research in equine lameness, laminitis, colic and other areas. This year, the foundation's live and silent auctions raised over $118,000.  In 2008 alone, the foundation awarded 48 scholarships totaling $190,000 to help fund the education of veterinary students committed to equine careers, assisting them with the estimated $106,000 of debt the average new veterinary graduate faces.

Horse Owner Highlights

Veterinarians aren't the only ones who benefit from attending the convention. The Healthy Horses Workshop, an educational day designed just for horse owners, featured seminars on subjects such as eye diseases, training and control from the ground, pain-free saddle fitting and nutrition.  Also, Gina Miles spoke about her experiences as a silver medalist in eventing at the Olympics.  

Recognizing the vital role of farriery and podiatry to the health and welfare of the horse, the AAEP once again organized a Farrier Program at this year’s convention.  Farriers were invited to participate in this day-long session on issues such as management of hoof wall separations and quarter cracks, the use of composites, foot and limb deformities in foals, breakover enhancement and other issues surrounding the prevention and treatment of lameness. Having farriers and veterinarians come together was informative and a lot of fun, too!

The trade show was another enjoyable aspect of the convention.  Watching veterinarians and technicians wander the huge trade show hall to view the hundreds of exhibits was like watching kids in a candy store.  It was a great opportunity to shop and compare equipment and supplies.  

If the Healthy Horses Expo or the Farrier Program sound interesting, mark your calendar for the 55th annual convention, to be held in Las Vegas, Nevada the first week of December. This is the same week as the National Finals Rodeo, so the trip should be both informative and fun.

Check out the AAEP web site at www.aaep.org to learn more about horse health, unwanted horses, and other topics of interest to horse owners.  

Think Before Breeding

Consider several factors before you decide to breed

by R. Paul Schwab, D.V.M., Kulshan Veterinary Hospital

Breeding horses, especially with artificial insemination, takes a fair amount of preplanning and organization. What stallion to breed to? Artificial or natural cover? How much does it cost? How old is the mare? What potential medical problems may come up when your mare gets close to foaling? Do you need to take on the responsibility of another horse? What about all the unwanted horses right now?

My original intention was to discuss the typical pre-breeding considerations, but then I started thinking about what is going on right now with the horse population and the economy, and I thought it better to step back and look at what we can do to address the unwanted horse issue.

There has been a growing concern to the point of epidemic about horses that are unwanted. Unwanted horses may be classified in several ways:
• Older “retired” horses that are healthy but need more care than the owner can give
• Unsafe horses with behavior issues
• Horses that have decreased use because of musculoskeletal issues or other medical problems
• Bureau of Land Management mustangs and burros that are not adopted out
• Perfectly normal horses, young and old, that cannot be cared for because of lack of room, money, food, or time

This last one is where I would like to focus some attention. The market is flooded with these horses, and they can be difficult to sell. Over the last year, feed costs and fuel costs have risen to an all-time high, and unfortunately the horses are the ones that suffer. Our clinic has definitely seen a rise in rescue horse farm visits this year, especially during the months when pasture was scarce. Reports are very common about abandoned horses left to scavenge on their own or dropped off into other people’s pastures. Basically, people can’t afford to raise the horses they already have, and the market is full of horses to sell.

Consider Before Breeding
The American Horse Council estimated that there may be 9.2 million horses in the U.S. right now. Approximately 90,000-100,000 horses were slaughtered annually before the slaughter ban in the US. What does this mean? There may be additional 90-100,000 horses per year in need of homes.

I don’t want to discourage all breeding. The horse industry needs the constant exchange of horses to stay alive, not to mention the genetics that can be improved annually by experienced breeders. A huge part of the equine economy is based on breeding horses and raising foals. My own job partly depends on the constant cycle of breeding and the prevention and treatment of diseases in the growing foal.

Just consider what is involved in breeding a mare, caring for and training a young horse, and what you will do with that horse when it has grown. It takes almost a year from breeding to the delivery of a foal and another two years to have a horse to ride. That's three years of breeding, training, feeding, and health care expenses. Ask yourself if you could adopt a horse and get the same results or find a horse at a reasonable price. Do you want to breed your mare because she is awesome and it would be cool to get a foal out of her, or is there some other reason? Are you contributing to the problem by over-breeding?

This is certainly a complicated and controversial issue, but it is one we should all be involved in. For more information on unwanted horses, the American Veterinary Medical Association and the American Association of Equine Practitioners both have sections on their websites with information and links. The Unwanted Horse Coalition (www.unwantedhorsecoalition.org) has a great website dedicated to this issue.

Red, The Rescue Horse

One horse's journey from neglect into health
by Dave Sauter, DVM, Kulshan Veterinary Hospital

Dealing with an animal neglect case can be a heart-wrenching experience. Unfortunately, animal neglect happens and someone has to cope with the consequences. With rising feed costs and hard times economically, such cases are regrettably on the rise. Today’s article is a story describing one such instance. In this situation, as in many cases of neglect, the owners simply lacked the knowledge and experience to care for the number of horses they had. The resulting condition of some of their horses was life-threatening. 

The Whatcom Humane Society (WHS) is the designated animal control agency of Whatcom County, assigned with the task of enforcing the codes, regulations and laws concerning animal care. They were called on earlier this year to investigate a case of animal neglect involving a large group of horses. The WHS examined all of the horses at the location and also inspected the shelter, the amount of space for the number of animals, the availability of feed and water, feed stores, fencing, etc. Ignorance of basic feed requirements had caused three of the horses to be at a state of starvation that was life-threatening. The WHS used its legal authority to seize the three horses. One of these three emaciated horses was “Red” (named by her eventual adoptive home). Based on her teeth and appearance, she was a twenty-something chestnut Arab cross mare. One of the other two horses was Red’s three-year-old daughter.

When the WHS removes horses in an emergency situation like this, they need a suitable location to provide food, water, safe housing and proper medical attention for the horses until a permanent new home can be arranged. Generally, one of several horse rescue facilities is called upon, but at the time of this seizure all the local facilities were full. Fortunately, a “foster home" was found. A local animal lover with a big heart, Lynn Larson, agreed to take Red and her daughter temporarily. Lynn has taken in foster animals before, including peacocks, llamas and poodles. In fact, she recently was awarded the WHS Act of Kindness Award. Lynn teamed up with a veterinarian, Dr. Christine Monroe, to tackle the horse rescue project. The starved, lice-infested, wormy pair of horses were taken in with loving arms. Proper food, water, shelter, blankets, and medicine for the internal and external parasites were generously provided. Lynn and Christine grew especially fond of Red because of “her kindness and will to live.”

After about a month in foster care, a home was found for Red and her three-year-old daughter. The new owners were initially very enthusiastic. Unfortunately, the two horses were more of a project than expected and they became too much of a burden. Red and her daughter returned to Lynn’s.

The filly’s condition improved faster than Red’s, and with that and her more youthful years, it wasn’t too long before a suitable home for the filly was found. Red, however, wasn’t improving as quickly. Although she gained greatly in strength and energy, she continued to look horribly underweight and rough. With her advanced years, a willing home couldn’t be found. Several people came out to look at her, but quickly lost interest and left. As the weeks turned into months, the options for Red were dwindling. The WHS was struggling to find homes for numerous horse cases. In spite of the fondness for Red, time, patience and resources were running thin.

Red’s guardian angel came in the form a veterinary assistant intern named Ruben from the Bellingham Technical College. In addition to his veterinary assistant duties, he was working for Lynn and knew about Red. While interning at Village Veterinary Hospital, he told one of their veterinarians, Dr. Rachel Bangert, about Red. He told her how Red had been starved, how Lynn and Christine had been providing a home for her for over three months, and how, because she couldn’t be placed into a permanent home, she might have to be euthanized. Although Red had improved considerably over the three months, her condition was still very poor. It wasn’t clear if she could ever recover from her emaciated condition. In spite of these doubts, Rachel and her husband, Ken, decided to take Red into their home and continue the battle to save her. The kindness in the mare's eyes may have influenced their decision.

After several more months of patience and numerous bills for feed, blankets, lab tests, deworming, trimming, delousing powder, dentistry, etc., Red has finally returned to good health, seven months after WHS seized her. She has made an incredible transformation from a near death rack of bones with a gut full of worms to an easy keeper that may need to go on a diet. Rachel has even started riding her. And she still has her kind eyes, which are perhaps a bit more grateful to be in her new home. 

A few observations concerning the subject of neglect:
• Horses that have been starved so severely that they have lost over 50% of their normal body weight are much less likely to survive.
• Taking on a starved horse is a formidable project. There is no guarantee of success and there is a lot of potential heartache and expense along the way.
• The WHS and the various local rescue facilities are always in need of financial support. Donation is another way to try to help these horses out.
• Feeding starved horses requires great care and patience. Starved horses are depleted of fat and carbohydrate stores and are burning protein from muscles for fuel. Their bodies are running in an altered metabolic state and they cannot be fed like normal horses. Feeding concentrated calories to the starved horse can lead to heart, respiratory and kidney damage, not to mention colic. Instead, numerous meals of good quality forage are recommended. Consulting with your veterinarian to outline a feeding program after an examination and laboratory tests is highly advisable.
• Expect six months or more for the emaciated horse to recover. Emaciated horses are in a fragile state – be patient. Feed changes must be gradual.
• Not all skinny horses are skinny because of neglect. Some skinny horses have owners who love them and provide them with everything possible to keep them as healthy as possible with special feed and care to try to get weight on them. Some old horses are like some very old people who simply stay skinny. Some of these old, skinny horses are active, happy and love to eat the gruel their owners provide. They have proper shelter and regular farrier and veterinary care. These horses do not need to be seized and the decision as to if and when they should be euthanized is between the owners and their veterinarian.

Happy Holidays!