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.

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.

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!

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. 

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. 

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.

Infectious Disease Part Two: Prevention

Keep your farm and family safe with Farm Biosecurity
by Dave Sauter, DVM

Last month Dr. Schwab reviewed five major infectious diseases that affect horses. This month we’ll examine methods and strategies aimed at preventing the movement of infectious disease onto your farm, otherwise known as Farm Biosecurity.

There are many reasons horses have to be hauled, including training, lessons, shows, breeding, racing, sales, trail riding and vacations, to mention just a few. The distances they travel are all across the map, from down the road a piece to across the country. Whether for business or pleasure, travel is part of life for most horses. Traveling does, however, create a pathway for transmission of infectious disease from the outside world to an individual farm.

Strategies that reduce the chance of bringing home unwanted pathogens begin before you leave the farm. They include items such as:

· Avoid compounding stressors. Travel causes stress that we have little or no control over; for example, the hours horses spend on their feet on the road, constantly making adjustments to maintain balance. They may be staying in strange facilities with unfamiliar horses, perhaps in far away locations with drastically different weather. The immune system is weakened by such stress, resulting in lower resistance to infection, and this comes at a critically vulnerable time (during travel) when there is increased exposure to pathogens. Many of our preventative medicine procedures also cause some temporary stress to the system, so plan ahead and schedule procedures such as vaccination, teeth floating, sheath cleaning and deworming at least three weeks prior to the scheduled event.

· Vaccinate appropriately and in a timely manner. Check your records or with your veterinarian to be sure the necessary vaccinations for the intended destination(s) are up to date. Vaccinations need to be given at least three weeks in advance to get the desired protective effect. Vaccination can, unfortunately, result in complications, such as fever and inflammation at the injection site. The three week minimum rule will allow enough time for recovery, just in case complications occur.

· Clean your supplies, tack and trailer prior to the trip. It is easier to keep things clean if they start out that way. Attention to cleanliness and hygiene is important at a time of heightened susceptibility to infection.

· Lighten up on grain meals a day or two prior to the trip. The digestive system is affected by travel. Lowering starch levels by reducing grain is beneficial.

· Make a checklist of supplies. Include such items as first aid kits (human and equine) and tools to pull a shoe. Consider bringing your own bedding, feed, water, buckets, and implements. Having a variety of dependable light sources can be invaluable as well.

· Begin monitoring your horse’s temperature before the trip, so you have a baseline.

When at the destination, check out the facilities. Probably the last thing you want to do when finally reaching your destination is inspect the stall, but it is important to take the time to ensure it is safe and secure. Strip the stall (horses love to eat strange, nasty bedding) and sweep out rodent and bird droppings that can harbor pathogens like Salmonella. Bed the stall with bedding from home that your horse is accustomed to. Knock down cobwebs (harbingers of pathogens). Check for nails sticking out of boards, remove any buckets and feed tubs and replace with your own, and check door latches. Discourage contact between your horse and other horses. Use your own tack and implements and avoid sharing them with others.

When an inanimate object acts as a vehicle to transport infectious material (e.g., mucus from an infected horse), it is referred to as a fomite. Don’t be a fomite. Just as tack and implements can carry infectious material on their surfaces, so can you. When you do come in contact with other horses, wash your hands afterward. A water hose is an excellent fomite, especially for diseases such as Strangles. Do not submerge water hoses into your water buckets; instead, fill them at a distance. Before heading home, clean supplies and tack again to avoid carrying infectious materials back to the farm.

Once you return home, it is ideal to separate the horses that traveled from the ones that didn’t. If possible, keep them separated for two weeks, monitoring and recording their temperatures daily. Ideally, new arrivals to a farm should be separated into yet another area for a 30-day period. Consider the separated areas potentially contagious, even if the horses appear outwardly normal. Organize chores so that the separated areas are the last you work on. Coveralls and different footwear can be put on as these isolated areas are entered, then removed when exiting. Keep separate implements, feed tubs, water buckets and water sources.

Cleaning and Disinfecting
Removing germs can be a challenge, especially in barns and trailers. Porous surfaces contaminated with soil and manure are particularly difficult. Although cleansers are not effective at killing bacteria, they can physically remove them, especially from non-porous surfaces. Use a detergent and a scrub brush to clean. Do not use a pressure washer because too much pressure will aerosolize contagious material, sending it into the air to circulate through the barn or trailer. A regular hose with a spray nozzle will generate adequate but not excessive pressure. After cleaning, allow surfaces to dry prior to disinfecting. Leftover water from cleaning will dilute the disinfectant, weakening its killing affect on the germs.

Not all disinfectants are created equal. Some, such as bleach, don’t work at all in the face of organic material. Its use should be limited to surfaces where nearly all organic material can be cleaned off first, such as shoes, buckets, grooming supplies, shovels, etc. Proper dilution of bleach for use as a disinfectant is 1 part bleach to 10 parts water, or three quarters of a cup of bleach to a gallon of water. Be sure to thoroughly rinse out feed tubs and water buckets after disinfecting them.

It is impossible to remove all organic material from some surfaces, such as stall walls, floors, floor mats, aisleways, etc., but there are disinfectants that are effective even when there is some organic material present, although these disinfectants can be more toxic and caustic. One example is Trifectant (peroxymonosulfate). With any disinfectant, carefully read the instructions to ensure the chemical is mixed and applied properly. Also follow label recommendations concerning protective gear and other safety issues. Do not mix chemicals.

Some diseases are zoonotic, which means they can pass from horse to human (e.g., Salmonella and MRSA). Planning ahead and good hygiene can help protect your farm, your horses and yourself.

"When There Was no Salt, we Ate Sand”

by R. Paul Schwab, DVM

Have you ever had one of those horses that just wasn’t right no matter what you treated it for? Even if it had good teeth, no parasites, and ate good feed and hay? Sand ingestion could be the culprit.

Horses may unintentionally ingest sand when grazing on loose sandy soils or if they are fed hay on the ground in sandy stalls or paddocks. Horses that are not getting enough forage because of overgrazed or overcrowded pastures are particularly at risk of sand ingestion. Young horses tend to be more curious and may eat sand as well.

Over time, sand accumulates in the large intestine. Gravity and the weight of the sand prevent it from passing completely through. The sand is very irritating to the lining of the intestine and reduces the amount of fluid and nutrients the intestine can absorb. Eventually this leads to diarrhea, and the horse can show signs of colic from intestinal irritation and spasms. With large amounts of sand, the large intestine can become impacted or blocked, often requiring surgical intervention.

Clinical signs of sand accumulation in the intestine include loose manure, ill-thrift (similar to the "ADR" mentioned in last month's article), mild to severe colic, lethargy, dehydration, and possibly sand in the manure. Often you can hear the sand in the intestine when listening under the belly with a stethoscope (sounds like the beach).

Colic from sand ingestion is treated with pain relief, large amounts of oral or intravenous fluids and electrolytes, mineral oil and psyllium. Psyllium is a bulk laxative fiber supplement (basically Metamucil) that is thought to suspend the sand granules and make it easier for the horse to clear the sand. In refractory cases that do not respond to this treatment, surgery is needed to remove the sand from the large intestine. I’ve heard of equine surgeons removing several trash cans worth of sand from the intestines of some horses. Radiographs are sometimes taken to make a diagnosis or double-check removal of the sand after treatment.

Diagnosis of sand ingestion can be made by clinical signs, history, and testing the manure. Sometimes you can see the sand in the manure if there is quite a bit. An easy way to test the manure is by placing 3-5 fecal balls in a rectal examination sleeve and mixing them with water to make a watery slurry. Hang the open end on the fence and let it settle for several minutes. If there is sand in the manure, it will settle into the fingertips. Unfortunately, this test isn’t always accurate. Horses can have sand in the intestine but not always in the manure.
Testing manure for sand

Prevention of sand colic is centered on preventing ingestion. Feed good quality and quantity of forage (hay and pasture) and use hay bags or racks when possible. Also feed grains in grain tubs or buckets. Salt and trace minerals should always be available to horses. Horses without salt or minerals will look for them in the dirt or sand.

Finally, there are several brands of psyllium supplements available commercially that can be fed as a preventative measure and/or treatment for horses that live in sandy areas. Talk to your veterinarian if you think your horse may be at risk for sand colic.

Equine First Aid

by Dave Sauter, DVM

Although we had snow in late April, the summer months should be fast approaching. There are more horse activities during these months and people are showing, pleasure riding, trail riding and traveling more with their horses. This is also breeding and foaling season. With all this activity, travel, and commingling of horses, there is more risk of illness, injury and other health related problems. Consequently, it is a good time to review the basics of first aid and what is included in a first aid kit.

Know Your Horse
The first step in first aid happens before a problem develops. Knowing your horse and getting familiar with what is normal will make it easier to recognize when something is abnormal. Whoever has the job of feeding the horses and cleaning their stalls has some of the best information on how they are doing. Horses are eating machines. Like other herbivores, they are capable--with the help of fermenting microorganisms--of digesting parts of plants we cannot. But they need a lot of the raw material and can spend up to 16 hours a day eating. The remaining hours are spent playing, socializing, sleeping, looking around, performing people-related activities and such. When horses are not eating, there is a problem: with all this food intake, there is understandably quite a lot coming out the other end. Horses defecate around a dozen times a day. With this much production, it doesn’t take long for a problem in the plumbing to escalate into something serious.

Horses are creatures of habit; routine and predictability help prey animals like horses feel more secure. Whoever cares for the horses often becomes familiar with their routines and habits and can notice when something deviates from the normal pattern. Subtle changes can be an indication that the horse is ADR. ADR is an abbreviation for the technical medical term, “Ain’t Doin' Right.” As a prey animal, it is to the advantage of the horse to conceal when there is a problem and it is more vulnerable, so subtle changes may be clues of an underlying serious problem. An ADR horse needs further observation, monitoring and investigation.

Know What to Look For
Of course, many signs of problems are more obvious. For instance, a horse with colic is experiencing visceral pain. With milder forms of colic, it might be off feed, stoic, or distant with a stressed look in its eyes. The horse might have a tight abdomen, occasionally paw at the ground or kick at its belly, curl its upper lip, and may lie down excessively. More severe visceral pain can lead to more violent symptoms, such as frequently lying down and getting up, more violent rolling and kicking at the belly, sweating, and more difficulty keeping the horse up and moving. Other things to look for include painful conditions of the eye, which result in squinting, excessive tearing, and sometimes swelling of the eyelids.

With any problem, make an initial appraisal of the horse’s condition from a distance. This allows observation of the horse’s general appearance and behavior, gives you a chance to assess the horse’s safety as well as your own and will help determine what supplies, if any, you will need.

For instance, if there is severe bleeding, some type of pressure will be necessary to apply to the wound. Often it is very helpful to get the vital signs of the horse, which include the temperature, heart rate and respiratory rate. Normal temperature is 99.0 to 101.0 degrees Fahrenheit. The normal heart rate is 30 to 44 beats per minute, and the respiratory rate is 8 to 16 breaths per minute.

Look at the gums by lifting up the upper lip. The gums should be moist, and normal color is pink. Abnormal color can be pale, dark pink, red or bluish. Check capillary refill time (CRT) by pressing on the gums with a finger, releasing, and counting how long it takes for the color to come back. Normal CRT is less than one second.

Skin turgidity is checked by tenting the skin up near the base of the shoulder, releasing it, and watching how fast it bounces back - it should bounce back very rapidly. If it doesn't, this could be a sign of more serious problems.

The First Aid Kit
There are many items that could be included in the list of useful supplies. Here is a list of essentials:

· Bandage materials are necessary to apply pressure to control bleeding; to cover, protect and stabilize a wound; and to support an injured leg. Duct tape is useful as an outer, more resilient layer for foot bandages. A word of caution about bandaging horses: a lot of damage can be done by bandaging a horse improperly. The longer a bandage is going to be in place, the more important it is that it be applied properly and monitored regularly.
· Thermometer
· Stethoscope (for getting the heart rate and listening to gut sounds)
· Antiseptic ointment
· Antiseptic spray
· Pen light
· Flashlight
· Watch with second hand
· Mild surgical scrub (for cleaning wounds--must be rinsed off!)
· Sterile saline (can be purchased at your veterinarian’s office or homemade by adding a heaping teaspoon of table salt to a quart of deionized water)
· Iodine solution (useful for foot baths)
· Epsom salts (useful for foot baths)
· Knife (for cutting rope, twine, etc.)
· Bandage scissors (blunt tip)
· Latex gloves (to protect you from contaminating your horse’s wound and vice versa)
· Fly spray
· Cell phone
· Veterinarian’s phone number(s)

Supplies need to be stored in a clean, dry, safe area in an organized, accessible location so necessary items can be readily found when needed. Tote trays can be helpful to organize smaller items that can be easily carried to the stall, paddock, field, or wherever required. For trail conditions, liquids or ointments can be transferred into properly labeled smaller-sized plastic containers with screw top lids. Watertight containers or Ziploc bags can be used for other supplies. Some type of soft carrying case can be employed to store everything. For those going on more extended rides or trips, talk to your veterinarian about other items to include when you are further from veterinary assistance (e.g., eye medication, anti-inflammatory medication).

We all hope our horses stay strong, healthy and happy. Unfortunately, accidents do happen, as do illnesses and other health problems. Knowing your horse, having basic first aid skills and keeping necessary first aid supplies available will help you be prepared.

Is Your Horse a Weekend Warrior?

by R. Paul Schwab DVM

Since this is the recreational riding issue as well as the beginning of the “nice” time of year around here, I thought I would remind everyone about “tying up” in horses. Just like us, horses don’t do well with a sudden return to heavy exercise without some sort of pre-conditioning. Exercise, as well as nutrition, is extremely important.

Tying up is a term that is frequently used to describe horses that, after some exercise or exertion, tend to get severe muscle cramping and/or stiffness. Horses that are tied up may show anything from slight lameness (usually stiff or shortened stride) to an inability to move or even get up. It is generally most noticeable in the hind limbs and back. The muscles may appear swollen and are often hard and painful to the touch. Other clinical signs such as sweating, elevated heart and respiratory rates, and looking back at the flank are also seen and can make it difficult to differentiate between tying up and colic, although both may occur together.

Medically Speaking
Tying up is the traditional layman’s term for Equine Rhabdomyolysis Syndrome (ERS). Other terms for this condition include azoturia, set fast, Monday morning disease, and exertional rhabdomyolysis. We will refer to it as ERS for the remainder of the article.

Diagnosis of ERS is mostly based on clinical signs and results of treatment, although your veterinarian can measure muscle enzyme levels from a blood sample to confirm the diagnosis. Also, muscle biopsies may be needed to help determine why the horse is tying up.

Treatment consists of stall rest (exercise may cause more muscle damage), Banamine or Phenylbutazone, and fluids. Grains should be avoided during the treatment period. In horses that are reluctant to move, a veterinarian should be called. Severe muscle damage releases myoglobin into the bloodstream, which at high levels is toxic to the kidneys. Horses with this condition may have dark brown urine or no urine at all. Intravenous fluids will help clear the myoglobin and other toxins produced by the muscle damage from the bloodstream.

Blood work can also be an important indicator of prognosis and guide for determining when to start exercising again. Your veterinarian may want to repeat a blood sample after the horse is better to see if muscle damage is still occurring.

Causes and Types of ERS
There are numerous theories about why some horses are more prone to this condition than others. Nutrition and genetics play a key role. The two heritable forms of ERS are Polysaccharide Storage Myopathy (PSSM) and Recurrent Exertional Rhabdomyolysis (RER).

· Horses with PSSM have a problem with sugar storage in their skeletal muscle fibers. Breeds predisposed to PSSM include Quarter Horses, Paints, Appaloosas, and draft breeds. The episodes are usually seen in unfit but good body-conditioned horses at the beginning of training or after a long or hard ride.
· Horses with RER tend to be Thoroughbreds, Standardbreds, or Arabians. Occurrences may be the result of a stress-related disorder of muscle calcium regulation. The classic RER horse is a fit young filly with a nervous temperament. In contrast to PSSM horses, RER episodes tend to increase as fitness increases.

The two factors that tie both of these forms of ERS together are lack of routine exercise and too much starch in the diet.

Feeds with high starch and sugar levels include most grains (corn, oats, and barley) and molasses, and to some extent lush spring grass. High starch and sugar diets result in rapid rises in blood glucose and insulin that seem to be responsible for exacerbating ERS in horses with PSSM. (As a side note, this same type of diet may be responsible for some Developmental Orthopedic Diseases as well.) Rapid rises in blood sugar can also encourage aberrant behavior in horses.

ERS Management
Control of ERS includes diet and exercise management. Reducing starch and sugar content in the feed is of utmost importance. Good quality forage (hay or pasture) should be fed at the rate of at least 1.5% of body weight per day. If extra weight or energy is needed, feeds with low soluble carbohydrates should be used (beet pulp, soy hulls, alfalfa pellets, rice bran, or canola oil). Current research is showing that feeding fats or oils with grains may stabilize the glucose and insulin rises that occur with grain diets. Feeding small meals more often will also level out the glycemic response.

Your veterinarian can help recommend a diet based on your horse’s activity level and body condition. Vitamin E and Selenium supplementation may be important as well.

Exercise is just as--if not more--important for management of ERS. Daily exercise is recommended and stall confinement should not exceed 12 hours per day. Pasture turnout is best. Thoroughbreds and other breeds with exertional rhabdomyolysis are usually quite fit already, but will respond to exercise and stress management such as pasture turnout, companions, etc.

Resources:
Harris, Pat, “Equine Rhabdomyolysis Syndrome,” Current Therapy in Equine Medicine 4, 1997 pp. 115-121
McKenzie, Erica, et.al, “A Review of Dietary Fat Supplementation in Horses With Exertional Rhabdomyolysis,” AAEP Proceedings 2002, pp. 381-386

EMS, Cushings, and Spring Feeding

by R. Paul Schwab, D.V.M

Over the next few months, our horses here in the Pacific Northwest will be challenged by the lush green grass we are blessed with after the months of rain and cold. For many, the grass is a welcome source of vitamins, protein, and carbohydrates and a break from relying on expensive hays and grains as a chief source of nutrition. For a growing number of horses, however, this same grass can be extremely dangerous to their health.

Equine Metabolic Syndrome and Equine Cushing’s Disease are two metabolic abnormalities of horses that make them extremely sensitive to the sugar content of lush, rapid-growing spring grass and sometimes any green grass at all.

Equine Metabolic Syndrome (EMS) is a syndrome in which horses are extremely “easy keepers” and seem to put on weight with barely any pasture. They tend to have more fat over the crests of their necks, around the tail head, and in the sheaths of geldings and stallions. There seems to be a breed disposition, with ponies, donkeys, Arabs, Paso Finos, and Mustangs commonly affected, although any breed is susceptible. Horses with EMS are more prone to laminitis (founder), as well. Veterinarians usually diagnose EMS when they are called out to see an overweight horse or pony that has laminitis.

One of the reasons these animals have such weight and laminitis issues is because of insulin resistance. In technical terms, insulin resistance describes a decreased response of tissues to insulin-mediated glucose uptake. Basically, there is plenty of insulin in the horse's system, but the muscles, liver, and fat tissues have only limited response to it. Insulin is responsible for telling the tissues to take up and use glucose, which is their main source of energy. In the case of insulin resistance, the glucose stays in the blood stream instead of going into the tissues, causing hyperglycemia (high blood sugar).

Over time, high glucose in the blood is toxic to the lining of the vessels and other tissues and contributes to the development of laminitis. High sugar/starch in the diet, or in some cases any sugar, overwhelms the metabolic ability of the horse to maintain the proper amount of glucose in the blood. The fat that accumulates on the crest of the neck, rump, and sheath may actually produce chemicals that worsen this insulin resistance.

Equine Cushing’s Syndrome is another disease in which horses are more sensitive to sugar in the diet. Equine Cushing’s Syndrome, or pituitary pars intermedia dysfunction, is a disease in which an enlarged pituitary gland in the brain causes a cascade of hormonal changes that ultimately result in an overproduction of cortisol. Cortisol is the body’s natural stress response hormone, which is needed during times of danger, stress, etc., but over time can result in damage to multiple organ systems. It brings down the overall immunity of the animal and causes insulin resistance. Horses with Equine Cushing’s Syndrome tend to have long, curly-haired coats that don't usually shed out in spring, drink and urinate frequently, and have problems keeping on weight. They are also extremely prone to laminitis.

Both of these conditions require diets with little or no starch or sugar. Sugar and starch are classified as Non-Structural Carbohydrates (NSCs). Examples of feed ingredients high in NSCs are corn, oats, barley, and molasses. These ingredients are low in fiber and high in sugar. Lush green grass can fall into this category because it is high in natural sugars called fructans. Ingredients low in NSCs include most hays and hay pellets, beet pulp, rice bran, soybean hulls, and oils. Knowing this information can help you formulate a proper ration for horses with EMS and Cushing's Syndrome.

Feeding Strategies
Obese Metabolic Syndrome Horse --Feed grass hay at the rate of 1.5-2% of their body weight per day (15-20 lbs. of hay per day for a 1,000 lb. horse). Yes, you really need to get into the habit of weighing your hay! Feeding a vitamin/mineral supplement is recommended because grass hay may not have the nutrition the horse needs. There are multiple commercial “super supplements” that have added protein as well that are ideal to feed to these horses. Don’t forget, these guys still need exercise. It helps the weight loss and encourages the tissues to utilize glucose.

Thin Metabolic Syndrome or Cushing’s Syndrome Horse--The diet for this type of horse is basically the same as the previous with the addition of extra calories in the form of fat and/or concentrate with a low non-structural carbohydrate level (low starch and sugar). Beet pulp is an excellent feed ingredient for these horses because it is low in NSCs but higher in calories than hay alone; it does need to soak in water before feeding, however. Beet pulp also works well for horses with dental problems. Fat can be fed in the form of rice bran or canola oil.

There are also several commercial diets now available for horses sensitive to starch and sugar. Most feed companies have developed their own versions, such as Nutrena’s Safe Choice™ and Lite Balance™, LMF’s Low NSC Stage 1™ and Complete™, Purina’s Well Solve™, and Elanbaas’ Nutracool ™and Equibalance™. Talk to your equine nutritionist or veterinarian for help deciding which may be the best choice for your horse’s specific needs.

What about grass? In general, lush green fast-growing grass is a problem for these horses. For much of the country, this growth happens in springtime. In northwest Washington, grass can be a problem through spring, summer, and the beginning of fall. Dr. Nicholas Frank offered a great guideline at this year’s American Association of Equine Practitioners conference: “Clients [should] pay attention to their lawn when managing an affected horse (horses prone to founder easy); their animal should be held off pasture when the lawn needs more frequent mowing.”

Grazing muzzles are a lifesaver for the overweight or sugar-sensitive horse. They allow the horse to be on pasture and get the exercise and nutrition they need while avoiding rapid weight gain and usually preventing laminitis.

As with any nutritional or medical issue with your horse, talk to your veterinarian before any management or feed change. Not every diet works the same for every horse. Also, horses with metabolic problems often have various other medical issues that need to be addressed, such as immunity problems, dental issues, and musculoskeletal concerns. Your vet can help you keep your horse at his best for many seasons to come.

Do I Have to Clean That?

by R. Paul Schwab, D.V.M.

Always frequent questions for veterinarians: "How often do geldings or stallions need their sheaths cleaned?" "Do you have to clean them?" "Why do they need cleaning?" As with any question, there are multiple answers depending on the horse.
The sheath houses the penis and associated loose folds of skin that stretch out and expand when the horse either has an erection or “drops” the penis to urinate. The skin inside produces a thick secretion called smegma. Smegma helps to moisturize and protect the skin of the penis and inside of the sheath. Because the inside of the sheath is a dark, moist space that doesn’t get much air, this smegma has a fairly foul odor.

During the summer and fall this smell can really attract flies, which can be very aggravating to the horse and induce skin irritation and allergy on the belly around the sheath. Of even more concern is the "bean." The bean, as it has been named, is a mass of smegma that collects in a cavity that surrounds the end of the urethra (the urethra is the tube in the penis where the urine comes out). If this bean gets large enough, it can actually put enough pressure on the urethra to prevent urine flow. This can be life-threatening if not caught in time.


How do wild horses survive without sheath cleaning? Well, wild stallions (no geldings in the wild) are breeding multiple mares in their group, which naturally removes/cleans these secretions. Geldings obviously aren’t breeding mares, so they may need more cleaning. Every horse is different on the amount of smegma they produce and may vary in how clean they keep themselves. Not every horse always drops to urinate, so the urine really makes the inside of the sheath a mess.

Horses that need sheath cleaning may have swelling in the sheath area, discharge, or even discomfort. Some horses will stretch out to urinate, but the stream will be weak or not flow at all. These signs can be confused with signs of colic.

Some animals will let you check their sheaths without sedation, but it can be risky. A great time to check sheaths is during routine sedation for teeth floats or other veterinary procedures. Usually, the sedation will relax the muscles of the penis so that it will drop and a complete exam can be accomplished.

When cleaning the sheath, it is important to remember that the smegma is there for a purpose. It moisturizes and protects the penis and the inside of the sheath. If it is cleaned too much or with products that dry and irritate, there will be more problems than with no cleaning at all. There are commercial products that are made specifically for cleaning, such as Excalibur®; mineral oil works for breaking up the smegma as well. Never use surgical-type soaps or wound cleansers such as Betadine or Chlorhexadine. Warm water from a hose helps to remove both debris and soap.

Above all, be careful. There are many horses that allow their owners to check and clean the sheath, but it is very easy to get kicked while working under the horse's belly. Also, “beans” can be difficult and sometimes painful to remove.

Stallions are of special concern when it comes to sheath cleaning. Smegma can harbor bacteria and viruses that can be spread to the mare during breeding. Stallions that are used frequently for breeding are inspected and cleaned often when they are about to breed the mare.

Take-Home Messages Concerning Sheath Cleaning:
1) That yuck is there for a reason
2) Don’t clean too often
3) Be careful!

Ask your veterinarian to check your horse’s sheath during times the horse is sedated. They can show you how to clean it and if it even needs cleaning at all.