Foal Losses: Equine Industry Media Briefing

Thoroughbred industry leaders, veterinarians, researchers, and farm managers met with the media at the Gluck Equine Research Center in Lexington, Ky., for a press briefing on the current fetal/foal loss syndromes happening in the state. While there are no answers as to the cause of current situation, there are defined paths being taken that everyone involved hopes will lead to the cause of the tremendous losses of late-term foals and early embryos in Kentucky broodmares.

One of the main thrusts of the meeting was to call on all farms that receive a survey from the Kentucky Thoroughbred Farm Managers Club and researchers at the Gluck Center to return the information promptly. Only through this broad gathering of information can the facts of this situation be revealed.

“We need to identify factors that could be contributing to this problem,” said Dr. David Powell, an experienced epidemiologist from the Gluck Center. “This has happened quickly over a wide extent of farms, but there are a number of farms that have not experienced problems. It will help us to get information from all farms.”

Preliminary Information

Lenn R. Harrison, VMD, Dipl. ACVP, Director of the Livestock Disease Diagnostic Center in Lexington, gave a report on what his staff has seen thus far at the diagnostic lab. He said since April 28, 2001, the Diagnostic Center has received 318 aborted/stillborn equine fetuses/foals for diagnostic testing and evaluation. Harrison reported that during the same time period in 2000, only 46 aborted/stillborn equine fetuses/foals were received. “This represents a nearly 700% increase in submissions of equine fetuses/stillborn foals for this timeframe,” he said.

Most of the fetuses were from Thoroughbreds, said Harrison, although there were numerous other breeds represented. This points to the fact that whatever the problem, it affects broodmares, not just Thoroughbreds.

Harrison also noted that 25 fetuses from 50 to 80 days of age have been submitted for testing. “We don’t usually expect to receive early fetal losses because they usually are not found,” he explained. “Receiving as many as we have is remarkable and give us samples to test.” Each submission will be handled independently and will have a case report written up by the professional and technical staff “who are specialists in essential disciplines in veterinary diagnostic laboratory medicine. Specialists involved are pathologists, bacteriologists, serologists, toxicologists, and virologists.”

The testing has revealed that there are some pulmonary changes in the lungs that appear to be a mild pneumonia. “This has been the only remarkable observation made on gross examination” of the submitted foals, he said.

Toxicological examinations have shown that the samples are negative for nitrates and nitrites. Tests have been normal for levels of copper, iron, selenium, and zinc in mare sera.

All samples have been negative for equine herpesvirus 1 and 4, equine arteritis virus, and adenovirus. ”Attempts to isolate an ‘unknown’ virus are in progress, but we don’t expect there is one present,” added Harrison. None of the samples have been positive for leptospirosis.

Aerobic bacteriologic cultures of internal organs of 154 foals and seven fetuses have resulted in positives for the following:\

  • Actinobacillus equuli in 45
  • Streptococcus spp in 75
  • A. equuli and Streptococcus in 2
  • Streptococcus zooepidemicus in 2
  • Staphylococcus sp in 1
  • Coliforms in 3

Harrison did not think any of these bacteriologic results were significant to the current situation.

Sequence of Epidemiologic Events

Powell and Dr. Roberta Dwyer, also an epidemiologist at the Gluck Center, were first alerted to the situation on May 2. They visited two farms experiencing problems on that date. The following day, a meeting was called with veterinarians and research colleagues at the university to help identify the problem and determine what samples needed to be taken to begin an investigation.

The number of phone calls from veterinarians and concerned owners increased “significantly” on Friday, May 4, and by Derby Day, Powell and Dwyer knew they needed to get a handle on the incidence. On Sunday May 6, an informational fax was sent to area veterinarians with what limited information was available.

A questionnaire was sent to area Thoroughbred farms on Monday, May 7, through the Kentucky Thoroughbred Farm Managers Club. “We hope the results will be available by the end of Wednesday (May 8),” said Powell. “That should give us an accurate picture of what is happening. We can identify farms with and without problems to help identify factors that are contributing to the situation.”

He added that there has been tremendous cooperation from all the farms in getting information.

Also on Monday, May 7, a meeting was help with a wide array of specialists, such as pasture management consultants, to help identify areas of pasture chemistry and possible toxic agents that could be investigated. Powell said samples taken from horses and pastures are under investigation.

Powell paused at this point to emphasize that nothing that was happening in Kentucky was in any way connected to current events in Europe or the United Kingdom. He said that while this outbreak is dramatic in nature, it is not a contagious disease. “There are environmental factors that come into play that exacerbate this situation,” Powell added. “In 1980, farm experienced a similar syndrome. We think the spring, cold, and drought could have exacerbated the condition.”

From A Vet’s View

Dr. Roger Murphy, a private practitioner and the current president of the Kentucky Veterinary Medical Association and the Kentucky Association of Equine Practitioners, said veterinarians and managers are trying to use any means to help the problem. This includes conservative therapy such as administration of domperidone (used in cases of fescue toxicity) and Regumate (to supplement hormones) and keeping mares off pasture as much as possible.

“That’s not going to solve the problem,” he admitted, “but we’re trying to help.”

Murphy also encouraged the industry not to panic and offered some encouragement as well as some reality. “There are two months left in the breeding season. The early fetal loss mares are cycling back, and there’s no reason to believe they won’t re-breed. But the late gestation losses are hard on the industry. You couldn’t ask for a better place if you have to have a problem like this because of the expertise we have.

Down On the Farm

Steve Johnson, president of the Kentucky Thoroughbred Farm Managers Club and operator of Margaux Farm in Kentucky, said there are more than 400 farms represented in the Farm Managers Club, and “we’re working in cooperation with the Gluck Center.

“Every farm in Central Kentucky is affected to some degree,” he said. “The Club is trying to help gather information and help determine management protocols that will help. On our farm, we don’t know the extent of the problem. We are finding dead or dying fetuses. We don’t know when it started or when it will be over.”

Johnson also voiced his gratitude for the vast array of veterinary and research expertise available close at hand. “We are fortunate to be in Central Kentucky with the Gluck Center and the great minds and resources that offers.”

He said that farm managers are being encouraged to work as “honestly and forthrightly” as possible with the Gluck Center to get the facts.

Media/Industry Q & A

Q: How many mares are empty?

Powell: This is the primary reason for the questionnaire. The early losses were picked up primarily by vets at 60-65 days doing ultrasound for fetal sexing and at that time identified fetal loss. It’s an ongoing situation. As more mares are examined, we will get a more definite answer.

Q: Are there any other animals affected:

Harrison: There are no reports in cattle or other species. Ohio, Indiana, Illinois, and Tennessee diagnostic labs are not reporting problems (in horses or other animals).

Q: How many pregnant mares are involved?

Johnson: The early embryonic loss is from mares bred in 2001. The actual full-term or close to term foals lost are from the 2000 breeding season. With the early embryonic loss it’s speculative. Some farms have lost 20%, some 70-80%. (David Switzer, Executive Director of the Kentucky Thoroughbred Association, offered from the audience that the mare population in Central Kentucky usually is about 18,000, although all of those are not in-foal mares.)

Q: Are there any mid-pregnancy losses?

Harrison: One Southern Hemisphere breeder brought in an aborted fetus or two. There are non-Thoroughbreds that are losing foals at six to 10 months of gestation.

Q: Are mares not cycling normally?

Murphy: The only thing we see in the early embryonic loss mares is that they come into heat. When they are checked, they are either completely void or in the process of getting rid of the fetus. The mares with 35-40 day losses seem to come back into heat and are cycling. Many have been re-bred. We feel that the fetal tissues are affected and the mare only has a mild inflammatory process that is transient and not long-term for the mare.

Q: How are you finding the early embryonic losses?

Johnson: Usually ultrasound exams are done at about 18 and 28 days (of gestation), then subsequent exams are done manually (without ultrasound). Manually, vets are finding discernable vesicles, but can’t tell that the conceptus is dead or dying. That’s only seen through ultrasound.

Murphy: We can feel (on manual exams) more edema and flaccidity to the uterus, but it’s hard to perceive a difference at that stage.

About the Author

Kimberly S. Brown

Kimberly S. Brown was the Publisher/Editor of The Horse: Your Guide To Equine Health Care from June 2008 to March 2010, and she served in various positions at Blood-Horse Publications since 1980.

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