Wonder where your veterinarian was the first week in December? If he or she is at the top of the game as an equine practitioner, you probably could find him or her enjoying the weather in Baltimore, Md., site of the 44th American Association of Equine Practitioners Convention. With Baltimore temperatures ranging into the 70s, it was tempting for the 4,081 attendees (including 2,208 veterinarians and veterinary students) to play hooky and stroll around the Inner Harbor. But the lectures were full, and the various continuing education opportunities seemed to meet the needs of the wide variety of veterinarians and equine professionals who attended the convention. There also was the largest trade show ever, with 273 companies exhibiting their wares for the veterinarians in attendance.

The annual banquet, an All-American Clam Bake theme this year, was highlighted with a performance by the Capitol Steps, whose political satire had the attendants rolling with laughter. Fort Dodge Animal Health was the sponsor for the evening.

Although the AAEP Convention program did not begin until Sunday, Dec. 6, the organization's work was taking place much earlier. As the various companies moved their materials into the exhibit hall for the trade show and veterinarians from all across the globe continued to stream into the airport and check into hotels around the city's Inner Harbor, the AAEP was holding committee meetings and members were participating in the Society for Theriogenology meeting held just prior to and in association with the AAEP convention (for more information see page 209).

The sessions opened with keynote speaker Ed Foreman, who went from farm boy to self-made millionaire by age 26. This motivational speaker had the participants talking, and thinking, about a more positive lifestyle. The keynote speaker, who also conducted a professional development seminar, was sponsored by Bayer Corporation.

Following is a summary of various business conducted during the AAEP convention, including information from committee meetings, scientific lectures, and demonstrations presented at the convention. In other parts of this AAEP Wrap-Up, you will find separate articles written from presentations given at the convention that offer you a more in-depth look at health problems your horses face and concerns you have as an owner or manager.

New officers were announced at the convention. They are as follows: president, Robert D. Lewis, DVM, Elgin, Texas; president-elect Benjamin Franklin, DVM, Miami Lakes, Fla.; vice president Wayne McIlwraith, BVSc, PhD, Dipl. ACVS, Colorado State University; treasurer, John W. Paul, DVM, MS, Easton, Penn.

New board members are as follows:

Harry W. Werner, VMD, N. Granby, Conn.; Edward W. Kanara, DVM, Kennett Square, Penn.; Eleanor Green, DVM, University of Florida College of Veterinary Medicine, Dept. of Large Animal Clinical Sciences, Gainesville, Fla.; John M. Harris Jr., DVM, Grand Junction, Colo.; Stephen M. Reed, DVM, Columbus, Ohio; Nat T. Messer IV, DVM, Columbia, Mo.; Michael T. Martin, DVM; Texas A & M University, Equine Section, Large Animal Clinic, College Station, Texas; Barrie D. Grant, DVM, Bonsall, Calif.; Mary H. Bell, VMD; Mannington Equine Services, Puslinch, Ontario, Canada.

Directors at Large are Glenn P. Blodgett, DVM, Guthrie, Texas; Larry R. Bramlage, DVM, MS, Lexington, Ky.; and Nancy L. Collins, DVM, Alta Loma, Calif. Equine Industry Board Member is The Honorable John Snobelen, Minister of Natural Resources, Toronto, Ontario, Canada.

Welfare Award

The AAEP chose the Thoroughbred Retirement Foundation (TRF), based in Shrewsbury, N. J., as the winner of the 1998 Lavin Cup, the AAEP's equine welfare award. AAEP recognized the TRF for its influential efforts to save former racehorses from neglect while rehabilitating juvenile offenders and prison inmates. Individuals involved in the TRF program gain emotional and educational benefits from state-accredited vocational training in horse care and management.

The TRF, a non-profit organization established in 1982, "exemplifies the model of a win-win strategy at work and has been the archetype for and supporter of similar organization nationwide," noted the AAEP. Satellite and TRF-operated farms in Connecticut, Kentucky, Maryland, New Jersey, and New York provide dignified and humane lifetime retirement for Thoroughbreds. In addition to the reformatory equine-education programs, TRF places horses in adoptive homes and in riding programs for the physically and mentally challenged. The multi-dimensional aspect of this organization's endeavors lends proof to the admirable station it holds within several industries.

The Professional Rodeo Cowboys Association and the United States Combined Training Association were Lavin Cup finalists.

The Lavin Cup is named for AAEP past president A. Gary Lavin, VMD, and recognizes non-veterinary organizations or individuals that have demonstrated exceptional compassion for or developed and enforced rules and guidelines that protect the welfare of the horse.

Distinguished Service Award

Ralph C. Knowles, DVM, was presented with the AAEP Distinguished Service Award and given a lifetime membership. He long has been an active and productive member of the AAEP, having presented 23 papers at conventions on topics such as infectious diseases (such as CEM, EIA, VEE, equine piroplasmosis, and African horse sickness) and working with electronic identification of horses. Only one other speaker has presented more papers at the convention, Dr. John Wheat, who gave 24 talks.

Knowles also has worked on many committees and liaison groups in the AAEP and within the industry. Presently a veterinary consult, he has been involved with Federal government service for most of his career. His jobs throughout the years have included Chief Staff Veterinarian of Equine Diseases at National Headquarters, Staff Veterinarian/Professional Development in Washington, D.C., Assistant Federal Veterinarian for Kansas, and Federal Field Veterinarian in Wyoming. He operated a private practice early in his career, and continues to consult, especially on treatment of babesia (equine piroplasmosis is a babesia). Upon retirement from Federal service in 1997, he was specializing in babesiacidal treatment of horses, serving as a field veterinarian with the Maryland Department of Agriculture, and working as a veterinary consultant on electronic identification of animals.

The positions he held with the USDA kept him constantly up-to-date with not only domestic, but world-wide equine disease. During his time with the USDA, he worked on forming an information bridge between the USDA and the AAEP.

Knowles has authored or co-authored 38 articles in scientific journals on equine infectious diseases and equine identification. He co-authored the chapter on Exotic Equine Diseases in Equine Medicine and Surgery third and fourth editions. He also, at various times, has served as a consultant on infectious equine diseases to the following: Canadian Department of Agriculture, Dominican Republic government, Mexican government, and a composite of Venezuelan Thoroughbred breeders. He has spoken at numerous international gatherings, including the Pan American Veterinary Congress, and World Veterinary Congress.

The late Gen. Wayne O. Kester, DVM, one of the founders of the AAEP, sent a letter of support concerning the nomination of Knowles for this award. In part the letter read:

"By his action, he, more than any other individual, is responsible for the success of many of our national and international equine disease prevention and control programs during the past 40 years. He has made numerous timely presentations on AAEP programs, also provided published papers and news releases apprising all AAEP members (and others) on actual and potential disease outbreaks, including description, diagnosis, treatment and control measures in vogue.

"All the foregoing is well known and a matter of record. What is not known is that in addition to providing regular liaison relations, he also provided 'off the record' information that guided us in promptly circumventing bureaucratic inertia in USDA.

"Knowles, off the record, continually kept us informed on where the road blocks were, thus allowing us to promptly generate the proper pressure at the proper time and place to cause USDA and/or congressional action.

"Knowles was a major contributor in our success. In doing so, he generated considerable more work for himself and placed himself in a position of risk. A lesser man would have "let Nature takes its course," and thus avoided the risk and additional work. Instead, and fortunately for the industry and AAEP, Knowles chose to do the right things. I have long admired him for doing so."

EVE Of A New Partnership

The AAEP and the British Equine Veterinary Association (BEVA) entered into an agreement in which the AAEP will publish an American version of BEVA's Equine Veterinary Education (EVE) magazine. Information contained in the American EVE journal will come from scientific papers published in the British journal. AAEP members will receive the American-published EVE journal as a benefit of their membership.

Another New Partnership

The Society for Theriogenology (reproduction) for the first time piggybacked its meeting with that of the AAEP. (For information from the therio section of the meeting, see page 20.) Juan Samper, DVM, Diplomate American College of Theriogenology (ACT), is the secretary/treasurer of the Society, which has about 2,200 members. All members are veterinarians interested in reproduction, and about 30% of those members are involved in equine reproduction. Only about 300 members of the Society are Diplomates of the American College of Theriogenology. There also are about 400 student members.

"I think (this combination meeting) was a good thing for us and them. I hope we keep it going," said Samper. "We put the reproductive part together for the AAEP's convention, and we put on wet labs. In the stallion reproductive laboratory, about 30% of the registrants were international members."

He said the Society wants to make horse owners aware of the option of having a reproductive specialist available for their mare and stallion management and health questions. Samper stressed that many of the Diplomates of the ACT are in the field, not just at universities doing research.

By Timothy C. Brockhoff

O. J. Ginther, VMD, PhD, of the University of Wisconsin's Animal Health and Biomedical Sciences, was selected to present the AAEP's 1998 Milne State-Of-The-Art Lecture, which was sponsored by Pfizer Animal Health. Ginther was selected for his outstanding work on the dynamic interactions be-tween the conceptus and the uterus.

According to Ginther, the embryonic stage lasts up until Day 40, when the proper term for the developing equine is the fetus. Day 40 "marks the beginning of the umbilical cord formation, completion of replacement of the yolk sac, and the beginning of fetal activity (head nods)," Ginther pointed out. The development takes place in the uterus, which is suspended by the broad ligament, which often "rides" on the mare's intestines. Following is information Ginther presented on how the embryo and fetus interact with the uterus and develop.

Embryonic Stage

The embryo enters the uterus at Day 6 after conception. From Days 11-15, the embryo is mobile and moves around the uterus quite a bit, according to Ginther. At about Day 14 or 15, fixation occurs and movement stops. The fixation, or implantation, of the embryo should occur at the uterine horn. However, before Day 14, the embryo can move anywhere in the uterus due to uterine mobility, which is sporadic and progressive, said Ginther.

It has been shown, according to Ginther, that clenbuterol blocks uterine contractions and therefore decreases uterine mobility, which causes the embryo to move less. Movement of the embryo is due to the uterus' contracting and expanding. Ginther said, "the embryo has a rough road to travel (in the uterus), so it doesn't move smoothly." Uterine contractions are stimulated by the uterus, with more contractions occurring behind the embryo, which causes the embryo to move forward.

Fixation, or cessation, of embryo mobility occurs about Day 15 in ponies and about Day 16 in horses. Most embryos fixate at the bend of the uterine horn by Day 16.

"Once fixation has occurred, the uterine tone becomes turgid and almost feels like a garden hose," said Ginther. By Day 30, the turgid tone of the uterus continues to increase, which results in a uterine interior with a smaller diameter. Essentially, the uterine horn that contains the conceptus continues to increase in tone and decrease in diameter. Ginther pointed out that a uterus of a pony is smaller than that of a horse, and the uterus of a young mare is smaller than the uterus of an older mare. If the tone of the uterus decreases, the embryo will dislodge from the site of fixation and be ejected from the uterus by uterine fluid. However, increased uterine tone will stimulate fixation. The ejection of the embryo also will occur if the embryo doesn't attach to the uterus.

The next event to occur is orientation, where rotation of the embryonic vesicle takes place in order to position the embryo properly in the ventral aspect of the vesicle. This orientation phenomenon occurs between Days 17-19. On Day 18, the embryo should be quite flaccid, according to Ginther. Postulated factors that cause orientation are the pressure of the turgid uterus and dorsal hypertrophy. If the uterine tone is poor, the embryo will not become oriented.

On Day 21, an embryonic vesicle is formed. On Days 24 and 25, there is some difference in the limb buds of the embryo, which is undergoing quite a bit of change and growth. The head and neck area of the embryo at Day 25 is very large; as a matter of fact, Ginther said, it is as large as the rest of the embryo. Ginther attributes the size of the head and neck to their importance.

By Day 30, the embryo is in amnion fluid. By Day 36, the yolk sac is quite small and disappearing rapidly, which marks the change from embryo to the fetal stage.

Fetal Stage

The bridge between the embryonic stage and the fetal stage occurs when the umbilical cord is formed. The umbilical cord starts forming at Day 40, and by Day 60, a substantial umbilical cord is in place. At the 40-day stage in development, the fetus' head is well tucked between the front limbs of the fetus, which is developing fast, said Ginther. However, in later stages of development, the head will not be tucked in between the front limbs as it is in the early stages. At that point, the fetus does not move around the uterus as the embryo did, but the fetus continues to move in its stationary position. The fetus might make a caudal or cranial presentation, but keep in mind that fetal presentation at this point changes frequently, as much as every five minutes.

The fetus continues to grow and develop, and by Day 40 its head nods. By Day 44, there is whole body movement of the fetus, and by Day 45, there is actual limb movement. At Day 46, fetal activity is substantially more than that of the 40-day-old fetus. The beginning of the mobility phase starts at Day 55, when the fetual movement gets quite rigorous. Ginther said that by Day 60, the fetus is still very active in movements and that possibly these movements could be the result of the developing neuromuscular system. Ginther pointed out that once you get beyond Day 70, it becomes hard to study the fetus. When that point is reached and there is no movement of the fetus, then there is a good possibility that the fetus is dead, noted Ginther.

At month three, the fetus is active about 27% of the time, with a total number of five fetal movements (changes) per hour. Things are very dynamic and busy inside the uterus, with the fetus moving into the uterine horn. While the attraction of the fetus to the uterine horn is not understood, it is documented that the fetus will move into the horn every so often.

By Day 100 there is a lot of brain activity. Ginther said, "The fetus seems to be practicing movements it'll make once it's born."

Horn closures and fetal presentation occur next. Not even parts of the fetus such as the legs are allowed in the uterine horn once they close. At this point, the fetus' inner ear is developed and the fetus can sense which way is up, and the incline of the uterus clues the fetus as to the position to stay in for birth. The uterus has a 40-degree incline.

At Day 240, the hind limbs enter the uterine horn, and they remain there until birth. The reason for this, hypothesizes Ginther, is to keep the hind and front limbs from becoming tangled in the uterus. By months eight and nine, the fetus is lying on its back in the uterus with its head and neck flexed. The limbs move freely and frequently, according to Ginther. Between months eight and ten, rotation of the torso is frequent. From the start of month 11 until birth, the environment in the uterus is very loose. Where the horn connects to the uterus, there is a lot of thickening of the uterine wall.

A mare has two uterine horns, but only one is used during pregnancy. This is Nature's way of allowing the horse to breed every year. The horn that is not used will be used the following year. In the last month of pregnancy, the limp horn loses some of its height and begins to flatten and there isn't much amniotic fluid for the fetus.

Fetal uterine rotation during foaling, which occurs several times during birth, should leave the foal with front limbs extended and its head and neck between them (this is the reaction of the foal to the uterus closing on it, according to Ginther). When the foal is about half way out of the mare during birth, its hind limbs will snap back, sometimes literally snapping like a kick. The foal should be on the ground in a matter of minutes if all goes as planned in the foaling process.


Infectious Diseases Committee

In the Infectious Diseases Committee meeting, Tim Cordes, DVM, Senior Staff Veterinarian, Equine Programs, with USDA, gave an update on equine infectious anemia (EIA). The consensus of his report and the discussions at the meeting were that EIA is not tested for sufficiently in the United States, and based on the NAHMS study, people need more education (see The Horse of December 1998).

The new federal form that goes along with a Coggins test for EIA still is under revision, but remarks have been taken from veterinarians in the field and the new form should reach practitioners in late 1999.

The incidence of positive reactors to EIA from Oct. 1, 1997, to Aug. 31, 1998, was 1,376 positive horses from 1,397,962 horses tested. That calculates to a 0.1% positive rate.

Two states had the greatest number of positive test results in fiscal year 1998. Utah, as a result of testing on a wild horse herd (The Horse of August 1998), had 117 positives of 10,483 horses tested. Arkansas had 310 positives from 56,603 horses tested. Texas still tests the most horses, with 383 positives from 141,940 horses tested (see map on page12).

Equine viral arteritis (EVA) always has been considered a topic of importance to the committee, but this year members emphasized the need to request that the USDA become involved in import testing of stallions and semen for the presence of equine arteritis virus. Some people feel the United States is becoming a dumping grounds for EVA-shedding stallions of several breeds. Also occurring is the importation of semen that is contaminated with equine arteritis virus. Then, unknown to the mare owner, the mare becomes infected with the virus and can be the focal point of an outbreak of EVA. Guidelines for breeding with shedding stallions or infected semen have been developed by experts in the field, but very few states or breed registries have implemented them as enforceable regulations. (For more on EVA see article on page 41 of the regular magazine.)

Equine encephalitis in the United States also was a topic of discussion. Cordes reported that in calendar year 1997, there were 282 submissions for equine encephalitis at the National Veterinary Services Laboratories. Of the submissions, 247 were for horses. There were 19 positive cases of Eastern equine encephalitis in horses, and six positive cases of Western equine encephalitis.

From Jan. 1, 1998, to Oct. 1, 1998, there were 191 submissions for testing, of which 138 were equine. There were 14 positives for EEE and five positives for WEE. There were two cases of EEE in humans in 1998; one in Rhode Island and one in Virginia. (See table for breakdown of testing.)

According to Cordes' report, in the past year, Mexico, the United States, Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama have reported enzootic Venezuelan equine encephalitis (VEE) virus variants or subtypes. However, no country from Panama north has experienced the clinical disease VEE caused by the subtype IA/B virus (the one which has caused disease in equines and was last detected in Central and North America in 1972).

In 1998, Dr. Tom Walton of USDA/APHIS formed a VEE reporting network comprised of information channels from International Services, Emergency Programs, the Centers for Disease Control, and the University of Texas Medical Branch in Galveston.

The United States has been considered free of contagious equine metritis (CEM) over the past 20 years largely because of federal import policies, according to Peter Timoney, FRCVS, PhD, head of the Gluck Equine Research Center in Kentucky. A number of animals, including four warmblood stallions and two mares, have been detected as positive for CEM during importation testing. These horses were cleared for the disease in their countries of origin.

"I think pre-export screening (in foreign countries) is not being carried out to the extent that it should and that there is a lack of proficiency in testing," said Timoney. There also were cases discovered of falsification of ages on papers of imported horses, which are required to be tested for CEM if over 731 days of age. (See The Horse March 1998.)

Another potential problem discussed was the need to address credentialing of laboratories that are testing samples for CEM in this country.

"I feel that unless these problems are addressed, we will face an outbreak (of CEM) probably in the non-Thoroughbred horse population," added Timoney. "I feel our testing will be breached at some point if something is not done."

Timoney also discussed the 1998 discovery of a CEM-like organism, which he said has "compromised our CEM-free status with international trading partners." It is felt that further investigation into this organism is of great importance.

Vesicular stomatitis (VS) has caused considerable problems in the horse population in the past few years. Brian McCluskey, DVM, MS, Diplomate ACVPM, gave an overview of the 1998 occurrence of VS in the United States.

The reported clinical cases in 1998 were almost exclusively equine (one bovine case), noted McCluskey. All cases were of one serotype (Indiana).

A Blue Ribbon Panel for VS was established by the U. S. Animal Health Association, of which McCluskey was chair. That panel said it is imperative that researchers develop a better understanding of the horse's immune response to VS and develop serologic tests to detect those responses. Also needed is an investigation of the potential reservoirs of VS, and of the vectors possibly involved in VS and their role in transmission.

Colorado State University has research ongoing to develop a vaccine for equines, but a vaccine is not expected any time soon. There is a vaccine for use in cattle in Central and South America, but McCluskey said he doesn't think it is something that could be used in the face of an outbreak in horses.

Josie Traub-Dargatz, DVM, Diplomate ACVIM, reported on the National Animal Health Monitoring Survey (NAHMS) for horses. She noted that two veterinary visits have been conducted on selected equine operations, with one more to follow. Included in these visits was testing of pasture, grain, and various biological samples from resident horses. All results are kept confidential, but some information was given back to individual horse owners. Results from these samplings will be available to the public later this spring.

Equine Welfare Committee

Among topics discussed was transportation of horses to slaughter. Cordes reported that three studies were conducted to help develop regulations for length of time for travel, timing of food and water, and segregation and prohibition of certain types of horses destined for slaughter (i.e., stallions, horses blind in both eyes, foals under six months of age, unfit horses, etc.). Cordes said when regulations are put into effect, federal veterinary medical officers will meet each load of horses as the animals arrive at the four slaughter plants in the United States to inspect each horse.

Also discussed was the Horse Protection Act, which was designed by the federal government to prevent "soring" of gaited horses during competition.

Pregnant mare urine (PMU) ranching was discussed, and it was felt that the industry was continuing to progress in educating horse owners and veterinarians on the care and well-being of horses involved in this industry. Wyeth-Ayerst and NAERIC (the PMU ranchers' organization) are developing programs to help ranchers improve the quality of facilities and horses in order to increase demand for the foals produced out of mares from which urine is collected while they are pregnant (to produce an estrogen replacement therapy for post-menopausal women; The Horse of March 1997). Data collected from ranches and research at the company's facility were included in a presentation during the AAEP convention. The company also will begin continuing education in the fall of 1999 for veterinarians who deal with PMU horses.

A discussion concerning transition facilities for retired racehorses (not rescue organizations) centered around follow-up on the animals following adoption. A member of the audience from the award-winning Standardbred Retirement Foundation noted that there is a large difference in organizations concerning post-placement follow-up. His group has developed a program for that purpose, and it would be happy to share with other organizations. Ralph Knowles, DVM, of the American Horse Council's Animal Welfare Committee, added that the AHC's group is working on having written material concerning horse care that will be available to organizations for distribution to new owners. Nat Messer, DVM, AAEP board liaison to the Welfare Committee, noted that the AHC is the best group to work on standards of care, with help from the AAEP and the industry.

Purchase Exam

Among the first committees to meet was the Purchase Examination Committee, chaired by Richard Mitchell, DVM. The first order of business dealt with the AAEP Report, the newsletter sent to members each month, and the Purchase Exam articles that appear in every issue. Since this particular component of the Report is one of the most popular features, the Committee proposed that it be continued. Also on the agenda for the group was planning for the 1999 AAEP Convention in Albuquerque, N. M. Discussion centered around a proposed three- to four-hour session at the convention dealing with purchase exams and focusing either on the various techniques involved in doing a purchase exam or the various disciplines and how purchase exams might differ from discipline to discipline. These were to be the two major activities for the year.

Held over from last year was a question dealing with written reports and purchase exams. The issue regarded whether a second or third opinion given in a special situation (e.g., a public auction of yearlings) should be held in the same regard as a pre-purchase exam and require a written report of some kind. Discussion focused on the need for documentation on the part of the veterinarian in case of litigation vs. the impracticality of having to write a report in such a frenzied atmosphere as a sale, where veterinarians might be asked to look at a set of radiographs twenty minutes before a yearling is led into the sales ring. The committee decided to study the issue further before deciding whether the language of the AAEP Guidelines covering purchase exams should be modified. A subcommittee in the form of a joint task force between the Purchase Exam Committee and the Racing Committee (if it agreed to the proposal) would be the ideal group to work on this question.

Another item on the agenda dealt with the way committees are run in the future. The 1999 purchase exam committee meeting, as will most committee meetings, will be run as a forum with a moderator and open discussion. The committee members felt that the two issues that should be carried forward to the 1999 forum meeting are the "Purchase Exam" articles in the AAEP Report and the forming of the task force. One of the possible issue topics for 1999 is the collection of hundreds of purchase exam forms that could be used as templates so an equine practitioner could develop a purchase exam form that best suits his or her needs and the disciplines for which the veterinarian is most prone to do exams.

Racing Committee

The Racing Committee was chaired by Jay Addison, DVM. After playing a major role in the early years of AAEP, racetrack practitioners now are a small percentage of the total population of the organization. The goal of the committee is to reflect the integrity of the profession and to restore the reputation of the racetrack practitioners, especially as it concerns administering medicines.

Part of the Committee's time was spent discussing an AAEP-sponsored educational program for owners of Thoroughbred racehorses and of racehorses in general. The question was whether there is a need to be more proactive concerning an educational program about what the racetrack veterinarian does, and, if there is a need, how best to fulfill it. It was recommended that this type of program be pursued as a way to promote the image and professionalism of equine veterinarians on the racetrack and to educate horse owners. The medication threshold issue occupied a great deal of the afternoon meeting as well.

Sports Medicine

On the agenda for the Sports Medicine Committee is the formation of an e-mail list group for committee members to enable them to communicate better with one another throughout the year. Future seminars were another topic that was addressed at the committee. One of the future seminars that will involve sports medicine is the American Equine Sports Medicine annual meeting. The allocation of research money also was brought up in this committee meeting. Specifically, it was mentioned that the AAEP Board of Directors has allocated money for research involving therapeutic options.

On a final note, an attendee of the meeting brought up the difficulty of three-day event courses. The members of the committee and the attendees agreed that courses for three-day events have become more difficult in the United States in order to compete with courses in Europe. The members of this committee felt that the courses have become difficult and that horses coming off the courses were showing signs of soft tissue injury, or more specifically, tendon and suspensory injury.

The committee felt that the trends in these courses was to make them consist of big and dramatic jumps, which often are not in the best interest of the horses. Committee members decided to begin a database of injuries that documents how much of a problem soft tissue injuries are in three-day events. Once this database has been established, the committee will evaluate the information and make a recommendation about the difficulty of courses if the committee finds that the course difficulty is the source of injury.

Horse Show

The Horse Show Committee members began their meeting by stating that there had been no significant changes in Canadian rules in the past year. The committee still was undecided on the AHSA's non-steroidal anti-inflammatory rule. It was noted that the AAEP Board of Directors did not come out in support the NSAID rule, and there still is quite a bit of disagreement on this topic among AAEP members. This issue was scheduled to be taken up further at the American Horse Shows Association's annual convention in St. Louis, Mo., in January. (Stayed tuned to our web site for more information on this rule direct from the AHSA convention.)

A representative from the American Quarter Horse Association was on hand to give a report on the AQHA's adoption of the AHSA's drug rule. The drug rule for the AQHA is almost identical to the drug rule for the AHSA since the AQHA modeled its rule after the AHSA's rule. The only difference is that the AQHA has passed some of the NSAID rules that the AHSA still is discussing.

One of the last topics reviewed by this committee was other factors that affect horses at shows. The committee came up with footing, stabling, transportation, scheduling of shows, and judging standards as pertinent to shows. According to the committee, there needs to be a standard for footing at shows and also a standard related to ventilation in stabling facilities at shows. Stalls need to be regulated for size, lighting, and height, according to this committee. There needs to be a standard against which to compare these items. The committee also agreed that there needs to be judging standards set on lameness, such as what is acceptable and what is not. Currently, it's up to the discretion of individual judges, and the committee feels that this needs to be uniform.

Multi-Media Learning Center
By Tom Hall

The AAEP Convention offers continuing education to veterinarians in many ways. In addition to the formal presentations on various topics ranging from medicine to reproduction to ophthalmology, there are the Table Topics and the Sunrise Sessions, where smaller groups assemble to discuss issues raised in such areas as racetrack, soft tissue surgery, and therapeutic options. Educational opportunities abounded at every turn of the convention center's cavernous hallways.

The Multi-Media Learning Center (MMLC) provides yet another educational opportunity. Open from Sunday to Wednesday under the direction of R. Bruce Hollett, DVM, the MMLC is filled with material that allows the veterinarian to delve further into subjects that might be of interest. There are CD-ROMs, radiographs, and videotapes on a variety of topics. There is even a computer available for veterinarians to check their e-mail.

In addition to an opportunity for practicing computer skills, CD-ROMs can store megabytes of useful information and provide that information with the click of a mouse. With the portability and popularity of laptop computers, it is possible to take an entire reference library on the road. Several of the CD-ROMs are designed as reference tools. For example, Poisonous Plants: A Veterinarian's Guide To Toxic Syndromes, by Murray Fowler, DVM, provides an alphabetized list of poisonous plants with the common name, the scientific name, and the poisonous syndromes listed. Clicking on the name of a particular plant pulls up a screen with a vertical icon bar. Using the various icons, one can maneuver through the information for particulars about that plant: the poisonous principle, the distribution, the conditions, the clinical signs, the diagnosis, and the management and treatment.

Another such reference available on CD-ROM is A Multimedia Atlas of Internal Parasites of Horses, by Anne K. Prestwood, DVM, PhD.

Another CD-ROM, Equine Tendon Sonograpy, by David Schmitz, DVM, provides a learning experience to the practitioner through audio and video. Different screens guide the viewer through the Introduction, Preparation, and Exam sections of the CD-ROM, which provide tips on how to examine the limb, how to prepare the transducer, how to put on the gel--not only where but why--and how to conduct the exam from different areas.

The radiograph section of the MMLC uses a series of X rays along with a case history that corresponds to that set of X rays in order to provoke thought and discussion among the practitioners. The case history gives some background of the horse (e.g., a three-year old Rocky Mountain gelding), the pertinent history of the horse (the horse developed acute lameness 10 days ago and has been limping and reluctant to stand on the left hind leg), what the physical exam revealed (mild degree of swelling of the pastern region without sensitivity to joint flexion or hoof testers; a left hind abaxial nerve block resulted in an 80% improvement), and the radiographs (in this case two radiographs of the left pastern). The final component is the question: what are your conclusions, impressions, and action plan at this time.

Altogether there are 10 of these sets of radiographs. They cover a wide range of problems and certainly give the veterinarians a chance to use their radiograph reading and diagnostic skills in determining a solution to the problem described.

There also are videotapes. Set up like a multiplex theater, the 10 stations have a video playing. The videos cover a wide range of topics. One might choose to watch a video on some aspect of surgery, medicine, or theriogenology. In addition to these categories, there is a miscellaneous section that covers topics ranging from conformation evaluation to show jumping or educating a green colt. The attractions currently running are announced on a board at the main desk, where the videos can be requested. The viewing areas have tables for taking notes and earphones for listening to the video.

Many of the videotapes and CD-ROMs are available for purchase, so if a practitioner sees something he or she would like to study further, it is possible to get a copy by contacting the appropriate company or institution.

Lyme Disease
By Tom Hall

Depending on the area of the country in which you live, Lyme disease might be a severe problem for you, and your horse. This especially is true during certain times of the year, usually fall and early spring. That is the time when the adult stage of the ticks that carry this disease might feed on wildlife and carry the organism to horses. Certain areas are more prone to the disease than others, including the far eastern and western United States. (The disease in humans has been diagnosed throughout the world.) The causative spirochete bacterium, Borrelia burgdorferi, often is found near water and in moist areas. Endemic areas for Lyme disease are more prevalent along coast lines.

The bacterium causes a multi-systemic disease that affects many species of animals, including humans. Ticks, especially the deer tick, are the vectors for the disease's transmission. The infection is acquired when animals (usually mice and deer) host the adult stage of the tick and are bitten by the insect; then the bacterium is carried to another animal.

The ticks must feed for 12 or more hours before infecting a horse; therefore, since the ticks are big enough to be seen and discovered in routine grooming, it is possible that careful inspection of the horse and regular grooming can discover the source of the disease before the tick can transmit the organism to the horse.

Symptoms include a shifting lameness, moving from joint to joint and limb to limb. Lyme disease also can affect the musculoskeletal system and the neurological system. Other signs include behavior changes and limited performance.

Sandra L. Bushmich, DVM, addressed the 1998 AAEP Convention in a talk entitled "Lyme Disease in Horses: Serological and Antigen Testing Differences." There has been a lack of controlled clinical studies of equine Lyme disease. The purpose of Bushmich's study was to determine if there were any serological or antigen tests that could distinguish clinically ill horses from those merely exposed to the disease. (A positive antibody test only proves exposure, not disease.) She also wanted to see whether those findings would be of any diagnostic importance.

The data revealed that clinically ill horses infected with Borrelia burgdorferi are more likely to be spirochetemic (presence of spirochetes in the blood) and spirocheturic (presence of spirochetes in the urine) along with having a higher incidence of positive immunoblots that possess antibodies to certain of the bacterium's proteins than the clinically normal, exposed horse. Eventually, this knowledge might lead to developing new and more accurate diagnostic studies.

Equine Lyme disease is very difficult to diagnose due to the fact that there are non-specific clinical signs coupled with limited diagnostic tools and a high incidence of subclinical exposure in endemic areas. There might be a 30-50% exposure rate among horses, but fewer than 10% will develop the disease.

Lab tests supporting the clinical diagnosis also help pinpoint the disease. A horse's response to treatment is a good indication that the diagnosis for Lyme disease was correct. Usually, a horse will show improvement within three to five days if treated adequately. One should be aware whether ticks have been a problem in a particular area and whether the horse has been in a situation where it might have been exposed to ticks, i.e., a pasture near a woods.

The treatment for Lyme disease has been extrapolated from human medicine. Antibiotics are the main form of treatment. Oxytetracyline and oral sulfatrimethoprim given over a three- to four-week period are useful in fighting the disease. Non-steroidal anti-inflammatory drugs (NSAIDs) often are added. A treatment regimen might dictate internal flora supplements as well in order to replace the normal intestinal bacteria that are killed by the antibiotics.

One word of caution, however. Jarisch-Herxheimer reaction might occur in fewer than 5% of the cases and might precipitate laminitis. The Jarisch-Herxheimer reaction is a transient, short-term immunologic reaction commonly seen folowing antibotic treatment of some diseases. It is characterized by fever and chills among its symptoms. The reaction has been attributed to endotoxin-like substances or antigens that are released by the killed or dying organisms.

There is a vaccine for dogs on the market, and a human vaccine is on the way. There currently is no vaccine for horses, although studies conducted at Cornell University might produce an equine variety in the near future.

Research Bites
By Les Sellnow

  • Julie Wilson, DVM, Diplomate ACVIM, University of Minnesota, reported on the influence of handling in shipping and at the laboratory on test samples for measurement of thyroid levels. She concluded that veterinarians should mail frozen samples with ice packs in insulated packages via overnight courier services to minimize changes in thyroid hormone concentrations brought on by handling procedures.
  • Philip D. Hammock, DVM, University of Illinois, reported on the effects of psyllium mucilloid, a substance included in commercial products for the evacuation of sand impaction. He reported that in a study involving 12 ponies, psyllium mucilloid had no effect on the removal of sand from the large intestine of ponies. During the 11-day test period, he reported, the ponies were able to pass approximately 70% of the sand whether or not they were treated.
  • Krista L. Seltzer, DVM, Diplomate ACVS, gave a presentation on the use of a sterile plastic bag to facilitate the removal of large ovarian tumors during standing flank laparotomy in mares. In a test involving eight mares with large ovarian tumors, the technique was employed and no complications resulted. All mares recovered and were discharged within three days from date of surgery.
  • Jan Kivipelto, MS, compared results from administering different compounds for the control of tapeworms. Best results, she said, was from administering pyrantel tartrate (Strongid C) on a daily basis. At the end of the test period, she reported, there were no tapeworm eggs found in fecal samples. However, a practitioner from Minnesota, during the question and answer period, said that she had found tapeworm eggs in fecal samples of horses that had been on Strongid C for a long period of time. The conclusion was that more tests are needed in varying geographic areas.  
  • Claire E. Card, BS, DVM, PhD, ACT, Western College of Veterinary Medicine in Saskatoon, Saskatchewan, described how the Feulgen staining technique can more quickly reveal abnormalities in sperm samples than other staining techniques.
  • T.N. Philips, DVM, MS, Illinois Hospital and Clinic, Naperville, Ill., described a closure technique for the repair of perineal lacerations in the mare. It involves shelf closure with the suture line in a semitransverse or transverse direction instead of the longitudinal direction.
  • William B. Ley, DVM, MS, ACT, Virginia-Maryland Regional College of Veterinary Medicine, described a milk testing technique that measures electrolyte changes as the mare approaches foaling. The technique allows the practitioner to better determine just when the mare will foal.
  • Pascale Chavatte, DVM, PhD, of France, discussed the field use of a refractometer to measure colostrum quality in the mare immediately after birth. Only one drop of colostrum is needed, Chavatte reported, and the measurement is easy to read and has very repeatable results.

Bapten Removed From Market

Bapten, the medication that received FDA approval for the treatment of bowed tendons in 1998, temporarily has been taken off the market due to "some" horses showing swelling of the tendons after being treated with the drug. The swellings are a little different than the swellings seen in field trials, according to Allyn Mann, equine products manager for Boehringer Ingelheim's Animal Health Division. Mann said, "There were some things unusual in a few horses, nothing significant. The precautionary stop sale (effective Oct. 29, 1998) of the drug was voluntary."

Various tests currently are being conducted on the drug to determine where the problem could lie. At press time, Boehringer Ingelheim wasn't sure if the swellings were a problem with the drug, or if the problem lay elsewhere. The date of the drug's return to the market still is not known.

Magnet Study

David Ramey, DVM, Phillip Steyn, DVM, BVSc, MS, Diplomate ACVR (radiology), and Joseph Kirschvink, PhD, studied the effect of therapeutic magnetic wraps on circulation in the third metacarpal (cannon bone) region. Their conclusion from the results of their study was that there was no effect of low-intensity static magnetic fields on blood circulation to the equine third metacarpal region.

"Even if there were an increase in circulation, that might not equate to a beneficial physiologic effect," the report concluded.

Ramey said claims of increased circulation under static magnetic pads cannot be supported by good evidence. He added that his study agreed with other scientific studies; and that there was only one study that concluded that magnets did increase circulation. (Ramey took time in his lecture to point out the potential design faults of that study, conducted at Minnesota, that could have led to their discrepant conclusions.)

Writers contributing to this article were Kimberly S. Herbert, Timothy C. Brockhoff, Tom Hall, Les Sellnow, Deirdre B. Biles, Michael A. Ball, DVM, Roberta Dwyer, DVM, Dipl. ACVPM. It also includes information provided by the American Association of Equine Practitioners

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