AAEP Convention 2004 Wrap-Up: Horseman's Day
Horseman's Day, as part of the annual American Association of Equine Practitioners Convention, just keeps getting better and better. And attendance is strong no matter where the convention is held. Most recently, the locale was Denver, Colo., on Dec. 8, and nearly 275 horse enthusiasts showed up for the day-long session. In addition to presentations that ranged from dentistry to Cushing's disease, the attendees had an opportunity to attend a mini-trade show. Ten AAEP Educational Partners had booths adjacent to the meeting rooms, including Bayer, Boehringer-Ingelheim Vetmedica, Equus, Fort Dodge Animal Health, Intervet, Nutrena, Platinum Vet, Purina Mills, Pfizer Animal Health, and The Horse.
The presenters included: Mary DeLorey, DVM, owner of Northwest Equine Dentistry in Washington (dentistry); Sally Vivrette, DVM, PhD, Dipl. ACVIM, of Triangle Equine Veterinary Services in Cary, N.C. (maximizing performance); Dana Zimmel, DVM, Dipl. ACVIM, Dipl. ABVP, assistant professor of equine extension in the department of large animal clinical sciences at the University of Florida (neonatal foals); Christie Malazdrewich, DVM, Dipl. ACVIM, assistant clinical professor in the department of veterinary population medicine at the University of Minnesota (Cushing's disease and metabolic syndrome); and Ken Bedell, DVM, of Cornell University (equine motor neuron disease).
Continuing as part of the format were question and answer periods that spilled over into private discussions in the wake of individual sessions.
DeLorey led off with her presentation on dentistry. "Just a float isn't enough anymore," she told her listeners. "Comprehensive dental care is needed." She said that new research in the past five years has enlightened veterinarians and horse owners concerning equine dental care. Along with that enlightenment has been the advent of advanced equipment, diagnostic tools, and treatment procedures.
Because of improvement in general care, DeLorey said, it's not uncommon for horses to live into their 30s. The problem is that their teeth developed to last into their 20s.
"Everything we as equine veterinarians can do to prevent the premature attrition of the horse's teeth will stand them in better stead to live better, longer lives," she said. Many equine dental problems begin at an early age, but many of these problems can be easily and quickly corrected if dealt with at that time, she added.
She posed these questions to her audience: "Did you know that all horses should receive a comprehensive dental examination before the age of 2 1/2, and at least yearly thereafter? Did you know that by the time most owners recognize that a horse is having difficulty eating or weight loss is apparent, that the horse's dental condition is likely to be severely abnormal? Did you know that many parrot-mouthed (over-bite) or sow-toothed (under-bite) horses can have near normal bites without surgery or orthodontics if the condition is recognized early? Did you know that periodontal disease is the number one cause of tooth loss in the horse? Did you know a qualified veterinarian can diagnose, treat, and--in many cases--prevent periodontal disease?"
She explained that equine teeth are hypsodont, which means that they continue to erupt over time. Once the horse has his permanent teeth, she explained, they continue to erupt at the rate of three to four millimeters per year. Since the horse's permanent teeth are about four inches long, that means he will have enough tooth length to service his needs for 20 to 25 years--providing that there are no problems along the way.
"Once your horse has reached the age of six years," DeLorey said, "all his permanent teeth are in position and in use. If your horse has had periodic, comprehensive dental care up to this time and has no severe malocclusions (bite misalignments) or dental disease, he's well-poised for lifelong dental health. He should receive maintenance care, including smoothing of sharp edges, minor rebalancing, and troubleshooting, every eight to 12 months. Horses involved in demanding disciplines, she said, might need dental care more frequently.
Older horses--those in the 16- to 18-year-old category--might require no more care than a younger horse, providing they have had the advantage of regular dental care along the way, she said. However, at this stage of the animal's life, close monitoring of his dental health is important.
"In the older horse," she said, "the crown that has been slowly erupting out of the jaw over his entire life is running out. This progression brings with it the tendency toward periodontal (gum) disease, the increased possibility of fractured teeth, diseased roots, and loose teeth."
DeLorey told her listeners that horses are "incredibly stoic," especially regarding pain involving teeth and gums. They will endure the pain and continue eating, she said, until the pain becomes very severe or until physical forces make it impossible to do so.
Her take-home message was this: "Prevention is the absolute key to equine dental health. The idea that a horse doesn't need dental attention until he is in his or her middle age must disappear. The tendency to abnormally wear the teeth is usually present very early in life. Minor abnormalities detected at the age of one to five years can usually be easily corrected and need never become an issue. If the same problems are left undiagnosed until that horse is older, much more aggressive techniques are required to correct the situation."
More information: www.TheHorse.com/ViewArticle.aspx?id=5436.
Vivrette discussed strategies for keeping performance horses healthy and fit.
"Maintaining a performance or pleasure horse represents a substantial investment of time and money," she said. "People sometimes put their efforts toward the purchase of a nice horse and a lovely truck and trailer, forgetting some of the basics that help improve horse health and performance."
It all begins, she said, with selection of the correct horse for the discipline involved. If one is to purchase a horse for the first time, a knowledgeable horse owner should be called upon for assistance and a pre-purchase examination by a veterinarian should be a priority, she said.
"A pre-purchase examination by a veterinarian can help identify problems that may interfere with performance," she said. "Just like humans, horses can be better at certain jobs than others. Try to select a horse that either knows the discipline of riding you are interested in or has a family history of talent in that area."
Vivrette told her listeners that horses need vaccinations against disease. Included on her list, with some of them recommended only in areas where the disease is endemic, were tetanus, rabies, Eastern and Western encephalomyelitis, West Nile virus, influenza, rhinopneumonitis, strangles, equine protozoal encephalomyelitis (EPM), and Potomac horse fever.
Proper conditioning of the performance horse is important, she stressed: "A horse that is improperly conditioned for its intended sport is at risk to develop muscle, tendon, and/or ligament injury if over-extended. A horse is said to be fit if it can perform its sport or discipline with minimal effort and low risk of injury. A conditioning program should include efforts to improve cardiovascular fitness, suppleness, and muscular strength. Many riders have a tendency to concentrate only on jumping, or dressage, or barrel racing, etc., and therefore confuse training with conditioning. Concentrating solely on training not only can lead to injuries from poor conditioning, it can also lead to behavior problems and boredom in your horse."
For example, if one is training a dressage horse with a 20-minute routine, the horse should have a conditioning program 20 minutes before and 20 minutes after the routine, she said. She also recommended riding horses up and down hills, and if they are not available, walking and trotting over cavaletti.
Vivrette followed DeLorey's lead in emphasizing the importance of good dental care of the performing horse. Other subjects that she touched on included:
Saddle fit--The saddle purchased 10 years ago for a 14.2-hand Quarter Horse might not be appropriate today for the newly acquired 16.3-hand Thoroughbred gelding. "It is a very good idea to have your saddle examined by a professional saddle fitter whenever you buy a new horse, if there are substantial changes in your horse's weight or conditioning, or if you start to have lameness, soreness, or behavior problems." See page 48 for more information on saddle fitting.
Nutrition--"Realize that horses, by nature, are designed to eat for 18 hours per day," she said. "The practice of feeding large amounts of grain and small amounts of hay is a recipe for colic, boredom, development of vices, and is a predisposing factor for development of gastric ulcers. When pasture space isn't available, it would be a good idea to feed small to moderate amounts of high-quality grass hay four times a day. Obesity should also be addressed, as this condition is considered a risk factor for the development of laminitis."
Shoeing--Many problems, she said, can develop from improper trimming and shoeing, with the most common stemming from failure to recognize and treat long-toe/low-heel foot conformation. Not all horses need shoes, Vivrette said, but shod or unshod, horses need hoof care at routine intervals.
Deworming--A regular deworming program, and varying the dewormers used, is vital. "Not all drugs kill all bugs," she said, and recommended that fecal samples be analyzed to determine which parasites are involved. "Formulate a plan to deal with them, then follow through on that plan."
More information: www.TheHorse.com/ViewArticle.aspx?id=5437.
Next came Zimmel, who discussed both routine and emergency care of the newborn foal. The best chance to improve the survival rate of a newborn foal, she said, is adequate advance disease prevention and planning, including a comprehensive vaccination program. She offered several suggestions on vaccinations; these can be found online at www.TheHorse.com/emag.aspx?id=5438.
Close observation of the mare prior to foaling is highly important, Zimmel advised. For example, if there is a vaginal discharge, it could mean that the mare has placentitis and immediate treatment might be called for to save the foal (see page 37 for more on placentitis).
Still another signal that something could be going wrong, she said, is the dripping of milk in advance of foaling. Not only is this a danger signal, but it means that valuable colostrum, vital to the foal's survival, is being lost. "That first milk is liquid gold," she said. "If the mare is losing milk, it is wise to obtain some colostrum from another source before the foal is born." The foal needs two liters of colostrum in the first 24 hours of its life, she said.
As for the birthing procedure itself: "You should be present for foaling. It can mean the difference between life and death for the foal," Zimmel stated.
Once the chorioallantois (placenta) ruptures and the allantoic fluid escapes, she added, the foal should be delivered in 20-30 minutes. A normal foal should be able to rest on its sternum within two to three minutes after birth. After the foal is born, she said, the one-two-three rule goes into effect--one hour for the foal to stand, two hours for it to nurse, and three hours for the mare to pass the placenta.
If the above schedule isn't followed, she said to contact the veterinarian because foals that don't stand and nurse soon after birth will become hypoglycemic (have low blood glucose) and lose the ability to stand. In addition, they are prone to become septic (with bacteria in the bloodstream) if they do not ingest colostrum as soon as possible after birth.
If a mare doesn't pass the placenta in a minimum of six hours, Zimmel said, she becomes at risk for metritis (uterine inflammation) and laminitis. When problems occur either in the birthing process or with passage of the placenta, a veterinarian should be called immediately, she said.
With some foals, blood screening for neonatal isoerythrolysis (NI) might be necessary. She said that NI occurs in 1-2% of the equine population and shows up most often with Thoroughbreds. The disease is a result of the foal absorbing antibodies in the colostrum that attack its own red blood cells, resulting in anemia, Zimmel explained.
She also outlined three major problems that can occur at birth.
- Red bag or premature placental separation. Under normal conditions, the chorioallantois ruptures and a stream of fluid is released. "Normal delivery should proceed with the protrusion of a white sac from the vulva. If a red velvet structure is protruding from the vulva, the person present should immediately cut it with scissors and try to gently pull the foal. The red structure is the chorioallantois, which did not rupture at the cervical star and the foal and the whole placenta are being expelled at the same time. When the placenta detaches from the uterus in this manner, the foal is no longer receiving oxygen and can die quickly."
- Dystocia, which is defined as abnormal labor. Under normal circumstances, Zimmel said, the foal is born with both front feet first with the soles of the feet pointing downward. Any other presentation can mean dystocia. The rule of thumb if there is an abnormal presentation is to call the veterinarian immediately.
- Not breathing. Regular breathing, Zimmel said, should start within three seconds of birth. The heart rate should be regular and about 70 beats per minute (bpm). "Implement resuscitation if the foal is not breathing, if the breathing is irregular, or if the heart rate is less than 40 bpm," she instructed. Resuscitating a foal manually can be exhausting, and she recommended that a commercial resuscitator be included in equipment available at birthing. A resuscitator costs about $140, she said. (For more information on manual resuscitation of foals, see www.TheHorse.com/ViewArticle.aspx?ID=3785.)
Zimmel said that after delivery is complete, the umbilical cord should be left intact for as long as possible, allowing the mare to break the connection when she stands. "This allows maximal transfer of blood from the mare to the foal," she said. "If the cord must be broken, do not use scissors, but pull the cord apart while holding close to the foal's abdomen."
Using straight iodine to treat the umbilical stump is unwise, Zimmel said, because it might scald the skin. The iodine should be diluted to the point of being iced-tea in color, she said, or a 1:4 solution of chlorhexidine can be used.
She left her horse-owning audience with these warning signs on the part of the newborn foal and what they might mean:
- Milk coming from the nose--aspiration pneumonia.
- Orange fluid coming from the nose or staining the hair--meconium aspiration.
- Changes in behavior, such as lack of affinity for the mare or wandering aimlessly--dummy foal.
- Milk on face--not nursing.
- Red gums--septicemia.
- Yellow gums--NI.
- Eyes sunken or tearing--dehydration, malnutrition, or eye problem.
- Weak pasterns, contracted tendons, joint or tendon laxity--serious limb problems.
- Swollen joints, lameness--infection.
- Diarrhea--bacterial, viral, or parasite problem. Foal diarrhea at seven to 10 days of age might be normal and a sign of foal heat diarrhea, but consult your veterinarian to rule out other possible illnesses that cause diarrhea.
- Weak and lethargic, inability to stand--sick foal.
More information: www.TheHorse.com/ViewArticle.aspx?id=5438.
Malazdrewich was the next presenter, and she gave clear-cut descriptions of two baffling conditions--Cushing's disease and metabolic syndrome. "Although the two disorders feature some striking clinical similarities--most notably a predisposition to development of chronic laminitis--the underlying disease biology is quite different in each case and successful management requires that the equine veterinarian distinguish between them," she began.
She first dealt with Cushing's disease--a pituitary gland disorder that results in hormonal imbalances. These imbalances result in a variety of clinical signs including:
- A long, wavy haircoat that fails to shed according to normal seasonal patterns;
- Excessive sweating;
- Poor athletic performance;
- Chronic recurrent laminitis;
- Weight loss;
- Muscle wasting;
- Passage of large amounts of urine;
- Delayed wound healing; and
- Increased susceptibility to infections.
The disease tends to occur in middle-aged to geriatric horses, with an average age of about 20 years at the time of diagnosis. In many cases, she said, diagnosis of the disease can be made via outward manifestations, but in others an endocrinologic (hormone) test might be required. Two primary tests are in use today--one is the dexamethasone suppression test, and the other is a test that measures the level of a hormone produced by the pituitary gland (ACTH).
Malazdrewich then turned to treatment protocols for Cushing's. She had this to say: "Optimal management of Cushing's disease involves a combination of both specific medication to normalize the function of the pituitary gland and supportive care to address and prevent complications associated with the disease. In both cases, management will be life-long as there is no way to reverse the disease process.
"In the early stages, specific medication may not be required and conservative measures such as body clipping to remove the long hair coat, strict attention to diet, and scrupulous attention to teeth, hooves, and preventive care may be sufficient," she continued. "If the horse is insulin-resistant, sweet feed and other feedstuffs high in soluble carbohydrates should be avoided in favor of diets emphasizing fiber and fat. In both mildly and severely affected horses, the importance of early diagnosis and aggressive treatment of bacterial infections cannot be overstated."
Two drugs have been used with some success to treat the disease, she told her listeners. One is pergolide, which acts on the pituitary to reduce the amount of hormones secreted. The second is cyproheptadine, which suppresses undue releases of cortisone by the adrenal glands. Pergolide is administered orally on a daily basis in a syrup form. Cyproheptadine is given daily, but comes in a tablet form.
Malazdrewich then discussed metabolic syndrome (MS), which often is first recognized when chronic recurrent laminitis becomes evident in fat horses lacking other foundation triggers.
"Obesity appears to be the central problem in both humans and horses suffering from metabolic syndrome," said Malazdrewich. "Although body fat is commonly viewed as an inert substance that functions solely as a storage form of energy, nothing could be further from the truth. Body fat, especially that stored in the abdomen, liver, and skeletal muscle, contains cells that are very active metabolically and hormonally, and when present in excessive amounts, their effects can trigger a cascade of metabolic disturbances leading to insulin resistance and persistent hyperglycemia (high blood sugar)."
Younger horses, compared to ones with Cushing's, develop metabolic syndrome if they are obese. Cases have been seen in horses 10 and under. And, she added, horses with metabolic syndrome normally have nothing wrong with the pituitary gland.
"Treatment strategies for equine metabolic syndrome focus almost exclusively on reversal of obesity and insulin resistance through strict dietary modification and implementation of an exercise program, if possible," said Malazdrewich. "Of course, horses suffering active bouts of laminitis cannot be exercised until founder has been brought under satisfactory control."
She noted that the most important aspect in the feeding of affected horses involves strict limitation of soluble carbohydrates in the diet--all grains and sweet feeds. The diet, she said, should have at its base good quality grass hay.
There are many unanswered questions about metabolic syndrome. She said: "Very little scientific work has been done on the condition at this point, and although there are some parallels with the human disorder called metabolic syndrome, it is still very unclear how deep those similarities go."
Equine Motor Neuron Disease
Bedell addressed one of the newer maladies that has shown up in the horse world--equine motor neuron disease. He characterized the affliction as any disease that targets the nerves that coordinate the muscle structure, similar to Lou Gehrig's disease in humans.
The disease was first brought to light in the 1990s, he said, and in the beginning was thought to be restricted to the northeastern United States. Since then it has been identified around the world.
Clinical signs of the disease include excessive lying down, a camped under stance (all four legs drawn in under the body), elevated tail, a weak neck that is unable to hold up the head, and abnormal pigment in the eye. He said the disease can progress very rapidly, causing death within a matter of weeks. However, if detected early, he said, it can be treated by supplementing the horse's diet with vitamin E.
The best treatment protocol involves getting the horse out on green grass, he said.
More information: www.TheHorse.com/ViewArticle.aspx?id=5440.
About the Author
Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at www.exclusivelyequine.com or by calling 800/582-5604.
POLL: University Equine Hospitals