A variety of topics, ranging from the sophisticated to the mundane, were discussed by presenters who offered their findings under the umbrella subject--The Foot.

Opening the session was Tracy A. Turner, DVM, MS, Diplomate ACVS, of the University of Minnesota. He discussed the "Predictive Value of Diagnostic Tests for Navicular Pain."

A study at the University of Minnesota involving 80 horses brought Turner and his associates to the conclusion that nerve blocks were extremely helpful in diagnosing navicular disease.

"This study," he reported, "has helped to clarify the clinical findings associated with navicular syndrome. Further, there is strong evidence that the field clinician should be able to differentiate navicular bone pain from other causes of palmar heel pain by using appropriate nerve blocks.

"I recommend that the first analgesic block that is performed should be in the DIP joint (distal interphalangeal or coffin joint). In this manner, if this block does not improve the well being of the horse, navicular pain has been ruled out as a cause of the lameness. If the injection does alleviate the lameness, there is a 90% chance that the cause of the lameness is navicular pain."

Turner also presented a second paper outlining what he characterized as an accidental discovery that acrylic material used to repair hoof wall damage can be impregnated with antibiotics in powdered form. The antibiotics help fight infection and speed the healing process.

Andrea M. Ritmeester, BVSc, of Purdue University, gave a presentation which took the position that "Coronary Grooving Promotes Dorsal Hoof Wall Growth in Horses with Chronic Laminitis."

"Our hypothesis," she reported, "is that grooving the dorsal hoof wall parallel to the coronary band relieves the external pressure on the dorsal coronary corium and restores coronary perfusion, thus promoting dorsal hoof wall growth.

"The results of this study indicate that coronary grooving significantly increases the rate of dorsal hoof wall growth in horses with chronic laminitis."

H. Joe Painter, a farrier at Auburn University, reported on the use of common PVC pipe in fashioning toe and heel extenders as well as leg casts for foals with flexural deformities.

Olin Balch, DVM, PhD, Oklahoma State University, reported that research has proven what show horse trainers and owners have long declared--that heavy shoes and long toes do cause the horse to elevate its front legs more than it normally would. However, he added, there is a caveat. Heavy shoes and long toes often cause the foot to land in an abnormal fashion and may be implicated in certain lamenesses.

Exercise Physiology

Topics discussed at the session on exercise physiology ranged from a horse's body-weight loss during endurance rides to the significance of the estrous cycle on performance mares. Harold C. Schott II, DVM, PhD, of Michigan State University, told his listeners that competition in endurance rides usually results in a loss of 3-7% of a horse's body weight and that a significant portion of this loss persists after overnight recovery. An occasional horse, he added, may lose 8-10% of its body weight and be at an increased risk of exhaustion during or after the ride.

"The results of our studies," he said, "suggest that the measurement of body weight loss could be a practical tool to help assess an endurance horse's ability to continue."

Luis J. Rivas, DVM, MS, Ohio State University, reported on research that studied the effects of sodium bicarbonate on performance horses. In brief, the study demonstrated that negative metabolic disturbances outweighed any positive effects of administering sodium bicarbonate.

Jonathan M. Foreman, DVM, MS, Dipl. ACVIM, of the University of Illinois reported on treadmill studies which were stimulated by the Olympic Games held in hot and humid Georgia. The studies, prior to the games, indicated that shortening Phase B (the steeplechase portion) of the three-day event would mitigate the harmful effects of extreme heat and high humidity.

Nikolaus G. Kriz, Dr. Med. Vet., University of Sydney, Australia, presented a paper on the effect of detraining on cardiac dimensions. He reported that after prolonged training, cardiac dimensions decrease during rest periods that are longer than four weeks.

"This has important implications for equine practitioners who have to compromise between the loss of athletic ability and the risk of serious injuries to racehorses," he said. "The results of the current study indicate that equine practitioners may advise short rest periods of up to four weeks in well-trained racehorses without a decrease in cardiac function."

Joan S. Jorgensen, DVM, North Carolina State University, reported that she had attempted to survey all AAEP members concerning their feelings on the "Significance of the Estrous Cycle on Athletic Performance in Mares." Of the 3,522 members surveyed, she said, 767, or 22% responded. Eighty-nine percent of the respondents, she reported, said that they treated mares for variations in performance that were associated with the estrous cycle. Out of 642 respondents, 492 (76.6%) used altrenogest (Regumate).

Table Topics

Equine viral arteritis (EVA) was discussed during a lunch-time table topic by Peter Timoney, MVB, MS, PhD, FRCVS, head of the Gluck Equine Research Center in Lexington. He said that there has been an increase in the confirmed occurrence of EVA in recent years, with 39% of 72 outbreaks having epidemics associated with abortion. Nine of the outbreaks occurred at racetracks in North America since 1977, with five having epidemic status. Timoney also noted that 25-55% of natural seropositive stallions are confirmed long-term carriers of the disease.

Discussions centered around the need for federal import policies on EVA since some of the outbreaks of EVA have been directly linked to imported carrier stallions or semen. He said there can be adequate safeguards put in place to prevent spread of the disease while maintaining trade. One veterinarian in the audience said there are states which don't allow vaccination protecting against EVA, but have no regulations against importation of semen infected with arteritis virus.

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