Horseman's Day, held for the third time as part of the annual AAEP convention, was another rousing success. Helping stimulate the interest and enthusiasm was the quality of the speakers. They couched their talks in terms the average horse owner could understand, but they certainly didn't talk down to them. It was the right mixture of scientific terminology and backyard talk to get the message across. Attendees demonstrated their interest with a barrage of questions at the end of each presentation. Following is a brief report on each talk.


R. Dean Scoggins, DVM, from the University of Illinois, covered bitting and dentistry practices to ensure that the bit is fitted properly to the horse's mouth.

"Correctly bitting a horse has very little to do with mechanics," he said. "It has everything to do with feel, timing, and balance. It is much more an art form than a science. In the hands of some individuals, a complex high-port curb bit is an instrument of communication with all the delicacy of playing a violin. In another person's hands, a thick hollow-mouthed snaffle may be as dangerous as a surgical scalpel in the hands of a monkey."

The first consideration in placing a bit in a horse's mouth, Scoggins said, is to be sure there are no abnormalities within the mouth that could cause discomfort. Old injuries, such as scars, sharp or abnormally located teeth, misshapen jaws, or previous tongue injuries, should all be noted and the necessary corrections made.

"Many trainers are having their veterinarians do a 'performance float' of their horses' teeth before introducing the horse to the bit," said Scoggins. "They remove all sharp edges plus rounding the front corners of the first cheek teeth, both upper and lower. This allows more room for mouth tissues and reduces discomfort when the reins are tightened and bit pressure increased. Wolf teeth and mature caps are also removed as needed. Properly performed dental work is often credited with putting 'power steering' on a horse that previously had difficulty wearing or accepting the bit."

Scoggins described and showed slides of a wide variety of bits and explained the type of pressure that each exerted.


Maureen Long, DVM, PhD, of the University of Florida's College of Veterinary Medicine, Dept. of Large Animal Clinical Services, stood in for Genevieve Fontaine, DVM, MS, Dipl. ACVIM, of Lexington, Ky. The prime focus of the talk was West Nile virus (WNV). She started with a brief history of the disease, pointing out that it was first identified in 1999 in New York. From there it has spread west across the United States and into Canada.

As of convention week (Dec. 4-8, 2002), Long said there were 13,600 confirmed equine cases for last year, with the heaviest hit area being the Midwest. Because many attendees were from Florida, she outlined the progress of the disease there. Thus far in 2002, Long said, there had been 463 confirmed equine cases in 44 Florida counties. There had been 28 human cases in Florida for the year (as of Dec. 13).

Of the 463 equine cases in Florida, Long said, 254 had not been vaccinated. For another 102, vaccination information was not available. Of vaccinated horses that still contracted the disease, 67 had received one injection instead of the recommended two; 29 had received two injections, and 15 had received three injections.

There are about 250,000 horses in Florida, Long said, and only 30-40% have been vaccinated. The proper protocol for vaccination, she said, is for the first injection to be given well before the onset of mosquito season and the second one to follow in three to six weeks. From that point on, the ideal approach is to give a booster injection every three to four months during the peak of mosquito season.

Acknowledging that such an approach could be costly if one had a large number of horses, the minimum that should be done was to give the two injections and follow up with whatever boosters the horse owner deemed affordable.

Long recommended that foals be given the first injection at three to four months of age, but pointed out that they need three booster shots before the vaccine is effective. She said that the vaccine is not labeled as being recommended for broodmares, but that it has been administered to them with no untoward negative effects.

Treatment can be expensive, with the average hospital stay being 10 days and the average cost running at about $1,700 per horse, with some being as high as $4,000. If the horse survives, she said, the recovery time can vary from one to 12 months.

"I'd like to say that we have some great treatment out there for West Nile," Long said, "but we don't." Treatment is strictly supportive, and can involve administering Banamine, DMSO, and hyperimmune plasma from heavily vaccinated horses.

Long also described the clinical symptoms, which include twitching, depression, increased body temperature, spinal cord disease, and paralysis.

She urged horse owners to take preventive measures by clearing up mosquito breeding areas, using insect repellent on horses, putting screens over stable windows, and keeping horses out of areas that are heavily infested with mosquitoes.


Also discussed was mare reproductive loss syndrome (MRLS), which struck
savagely primarily in Kentucky in 2001 and to a lesser degree in 2002. Long said that it's estimated that during 2001, foal loss through early fetal loss and abortion was somewhere between 4,000 and 5,000. The cause has been laid at the door of the Eastern tent caterpillar, which was present in great numbers during that timeframe.

Although MRLS is still a problem, she said, the loss rate has lessened during 2002. As of convention time, she said, about 500 early fetal losses and 165 abortions had been reported. Controlling the population of Eastern tent caterpillars and preventing horses from ingesting them are the prime preventive measures.


Frank Andrews, DVM, MS, Dipl. ACVIM, professor of equine medicine at the University of Tennessee, discussed equine gastric ulcer syndrome (EGUS). Ulcer problems are widespread in the horse population, he told the group, with 25-50% of all foals suffering from the affliction along with 60-93% of adult horses. Reaching the 93% mark, he said, are horses involved in racing or race training. In one study, it was found that 100% of the racehorses involved were suffering from ulcers. He added that about 92% of clinically ill horses have been found to also be suffering from ulcers.

Andrews explained that the horse's stomach is divided into two distinct regions--the esophageal or non-glandular region, and the glandular region. The non-glandular region, or squamous mucosa, involves about one-third of the stomach, and is devoid of glands. It is covered by stratified squamous epithelium similar to the esophagus. The remaining two-thirds of the stomach is the glandular region that contains glands secreting hydrochloric acid, pepsin, bicarbonate, and mucus. A sharp demarcation line known as the margo plicatus or cuticular ridge separates the two regions.

Ulcers in the squamous mucosa region, he said, are primarily due to prolonged exposure to hydrochloric acid, pepsin, bile acids, or organic acids. The squamous mucosa near the margo plicatus is constantly exposed to these acids, and this region is where gastric ulcers are frequently found in foals and horses because there is little or no natural protection against the acids.

Ulcers in the larger portion of the stomach (the glandular region) are primarily due to disruption of blood flow and decreased mucus and bicarbonate secretion.

"Horses out on pasture rarely have ulcers," Andrews said, because they are eating almost constantly and the presence of food has a buffering effect on stomach acids. "Proper feeding is the best way to prevent ulcers," he said.

Proper feeding in his terminology means providing the horse with a constant source of grass or hay. It has been found that alfalfa hay can help prevent ulcers as it normally is high in protein and calcium, which tend to neutralize the acid produced in the stomach.

"Feeding alfalfa hay to a horse is a bit like a human taking an antacid," he said. Conversely, a high-grain diet results in heavy acid production. Stall confinement also often results in more acid production and more ulcers. Physical and behavioral stress also are implicated.

Clinical signs of ulcers in adult horses include poor appetite and body condition, changes in attitude (from friendly to sour), a decrease in performance, and mild to moderate colic. In the foal, the clinical signs often include a grinding of teeth and lying on the back after eating.

The only definitive way to diagnose ulcers, Andrews said, is by examining the stomach with a long endoscope.

Treating ulcers is a good news/bad news scenario. The good news is that omeprazole, marketed as GastroGard, will effectively clear up ulcers in most horses and even prevent them if the horse is kept on the medication. The bad news is that it's expensive. Treating a horse with the medication once per day as recommended in the early stages can cost in the neighborhood of $500 per month. Sometimes a half-dose is given as a preventive measure, once the ulcers have been cleared up.


Michelle LeBlanc, DVM, Dipl. ACT, of Rood and Riddle Equine Hospital in Lexington, Ky., also presented good news and bad news on the use of new reproductive technologies in breeding programs.

The good news is that advanced reproductive technologies--such as cooled semen, frozen semen, embryo transfer, and gamete inter fallopian tube transfer (GIFT)--have given horse owners choices and freedom. The bad news is that there is a high price tag attached.

"Two things increase with new technologies--expertise and cost," LeBlanc said.

One of the most expensive methods to achieve a pregnancy, she said, is the GIFT approach, which involves taking an egg from an infertile mare, fertilizing it, then implanting it into another mare. The procedure could cost $20,000-$25,000, with pregnancy rates having risen to about 30% for a given breeding season.

Embryo transfer also can be expensive, she said. An embryo transfer foal at weaning must carry a value of $10,000-$12,000 for the owner to break even.

Improved techniques in handling and shipping cooled semen, LeBlanc said, have resulted in pregnancy rates roughly equal to natural cover, providing the semen is used within 24 hours of collection. When that is the case, pregnancy rates will range between 60-80%, the same as for live cover.

However, if semen is cooled for 48 hours, it will result in a pregnancy rate that's cut in half. Most stallions have a pretty good sperm survival rate for 36 hours, but it declines rapidly after that. However, she added, the semen of some warmbloods can survive for up to 72 hours.

There are more costs when inseminating with cooled semen, she said, because management is more intense, involving such items as frequent ultrasound examinations and the cost of shipping semen.

It is important for the mare owner to know that not all stallions' semen ships well. It behooves the horse owner to find out if the stallion he or she plans to breed to is a "good shipper."

When the sperm arrives for insemination, at least 30% of them should be progressively motile, which means they are moving in straight lines and not in circles, she said. Those live, progressively motile sperm should number at least 500,000.

She said the mare owner also should learn the details about semen shipment, such as whether the stallion is collected every day or every other day and how many shipments will be sent before the mare owner is assessed an additional charge.

When semen is frozen, then inseminated, pregnancy rates decline. "The more we manipulate the semen, the lower the pregnancy rate," she said. Only about 40% of the stallions in this country freeze well, and pregnancy rates range from 35-40% with frozen semen. Pregnancy rates are higher for younger mares than for older ones.

A major assist in obtaining pregnancies with both cooled and frozen semen has been the development of the hormonal drug Ovuplant. When Ovuplant is implanted beneath the skin of the neck or in the lining of the vulva, it insures a predictable ovulation providing the follicle is at the proper stage of maturity. Much the same effect can be achieved with human chorionic gonadatropin (hCG), which has been around for a long time, she said. Ovuplant is more specific for ovulation time and often is her treatment of choice when using frozen semen. There also is a difference in cost, with hCH costing $18-$25 and Ovuplant at $50-$60 per treatment.

The most important elements when dealing with transported semen, LeBlanc said, are communication, coordination, and cooperation among all involved.


Stephen O'Grady, BVSc, MRCVS, of Northern Virginia Equine, provided the presentation "Proper Physiological Horseshoeing." This, he said, "means let's get back to the basics. There may be no other routine procedure performed on a horse that has more influence on soundness than hoof preparation and shoeing. While methods may vary, the basic objectives when trimming and shoeing are to facilitate breakover, protect the sole, and provide adequate heel support."

Breakover, O'Grady explained, is that phase of the stride between the time the horse's heel lifts off the ground and the time the toe is lifted. During this phase, he said, the toe acts as a pivot point (fulcrum) around which the heel rotates.

Breakover can be significantly delayed with a long toe and low hoof angle--the angle between the front of the hoof wall and the ground. In that case, the toe acts as a long lever arm, requiring more time and effort to rotate the heel around the toe.

Shortening the lever arm, O'Grady said, facilitates breakover. "Depending on the horse, facilitating breakover may involve trimming the foot to decrease toe length and/or applying a rolled-toe, rockered-toe, or square-toed shoe."

The prime function of the sole, O'Grady said, is to protect and support underlying structures, particularly the coffin bone and blood vessels supplying the sole and wall. To function properly, the sole must be concave and firm to thumb pressure.

"Inadequate sole depth," he said, "is the most common cause of chronic sole bruising. Sole depth can be maintained simply by trimming the hoof wall appropriately and removing very little, if any, sole at each trimming."

O'Grady then discussed heel support. It is important to provide heel support to jumpers, he said, because of the great forces placed on the heels when landing after going over a jump and during weight-bearing phases of the stride. Landing after a jump, he said, can put up to 3,000 pounds of pressure on a foot. An abnormal hoof-pastern axis (such as the broken-back hoof-pastern axis) greatly contributes to overloading of the heels, which can cause chronic bruising and shearing of the hoof wall, along with chronic heel pain.

For years, horsemen thought hoof angles should be 48-55 degrees in front and 52-60 degrees behind. However, he said, that has been found to be erroneous. The correct angle, he maintained, occurs when the hoof-pastern axis is in alignment.

"A normal hoof-pastern axis," he said, "is one in which a line drawn along the front of the hoof wall is parallel to the pastern. In this situation, each of the bones of the digit--P1, P2, and P3 (the proximal, middle, and distal phalanx, respectively)--is in normal alignment."

A broken-back axis exists when the angle of the hoof wall is lower than the pastern angle. This condition, O'Grady said, contributes to navicular syndrome, chronic heel pain, coffin joint inflammation, quarter and heel cracks, interference during motion, and delayed breakover. This configuration often is caused by the long toe-underrun heel conformation.

The opposite issue is a broken-forward hoof-pastern axis where the angle of the hoof wall is higher than the angle of the pastern. This abnormality, sometimes called club foot, also contributes to coffin joint inflammation and pain in the navicular area as well as sole bruising.

"In addition to trimming the hoof to normalize the hoof-pastern axis," O'Grady explained, "it is important that the weight-bearing surface of the wall extend as far back as possible. Ideally, a line dropped down from the center of the cannon bone should land right where the heel ends, not well behind the heels as is often the case. If the heel can't be trimmed to provide optimal support at the back of the foot, the shoe branches can be extended to compensate and optimize the bearing surface area."


Jack Snyder, DVM, PhD, Dipl. ACVS, University of California, Davis, tackled the broad topic of colic, which is still the number one killer of horses. In general, he said, colic is defined as anything that causes abdominal pain, but the majority of the time, acute colic is associated with a problem of the intestinal tract. Non-intestinal causes of colic, he said, can include tying-up, laminitis, pneumonia/pleuritis, uterine twist, heart failure, urinary stones, and ruptured bladder in foals, to name a few.

All types and breeds of horses experience colic, although some types seem to afflict specific breeds more often. For example, he said, Arabians seem to have a higher incidence of enteroliths or intestinal stones than other breeds. The geographic area can also be implicated. For example, California and Florida have more problems with enteroliths than other states.

There are classic signs of colic, Snyder said, such as rolling and pawing. Other signs include looking back at the flanks, lying down longer than normal, sweating, and depression. Owners should be aware that older horses often don't show pain to the same degree as young horses. Also, males tend to show more pain than females.

Snyder then described equine gastrointestinal anatomy. He noted that no plumber would ever come up with such a design because there are areas where a large opening empties into a smaller one and other areas where material passing through the tract must make a sharp turn, all of which can set the stage for digestive problems and colic.

His take-home message was that horse owners should have a plan in case colic strikes. It should address the following:

  • Determine ahead of time which horses would be considered for surgery.
  • Determine how much money you are prepared to spend.
  • Have a transport plan and decide where the horse will go if surgery is an option.
  • Determine who is to make decisions if the owner is not available.
  • Inform the veterinarian of the insurance status of each horse.

If the horse colics, remove all food, notify the veterinarian, keep the horse as calm and comfortable as possible, and if the horse is rolling or behaving violently, try to walk him slowly. It is okay for the horse to roll, he said, providing that rolling doesn't endanger the handler or the horse.

The best way to prevent colic, Snyder said, is to provide the horse with a constant source of fresh water, maintain at least 60% of the diet as forage, avoid rapid changes in feed, have a good deworming program, maintain proper dental care, minimize transport stress, and watch him more closely during wide changes in temperature or episodes of violent weather.

In areas where enteroliths are common, he said, alfalfa could possibly be the problem. Two types of hay should be fed, with no more than 50% being alfalfa. An enterolith is formed from magnesium ammonium phosphate, and California alfalfa hay often is high in minerals that create enteroliths.

More information: See article #4022 at

About the Author

Les Sellnow

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 or by calling 800/582-5604.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More