Mystery illness kills 100 horses at farm

OCALA - As many as 100 horses died at a farm outside Summerfield during the past 10 days after the animals became ill, littering the farm's pastures. The death toll is unprecedented, say state veterinary officials.

The cause of the illness, so far, remains a mystery.

Owners of EquiTransfer, Jose Davila and his wife, Francis Ramirez, both veterinarians, had to euthanize the horses after the animals showed neurological problems and began collapsing. The couple say they think the cause of the illness was contaminated hay that wreaked havoc on the animals' nervous systems.

Davila and Ramirez would not say who they bought the hay from, but said that EquiTransfer is the supplier's only customer and that they have disposed of all of the suspect hay. Davila said they did not want to name the supplier because of potential legal consequences that could result if the hay turns out not to have been the problem.

"I wouldn't wish this on anybody," Davila said Wednesday regarding the death of so many horses. "[The horses] started trembling and fell on the ground. It was like they were having seizures."

Meanwhile, Davila and Ramirez, have sent samples from the dead horses, as well as from the hay, to toxicology labs in New York and Pennsylvania to determine what caused the illness on the 87-acre farm.

The farm also sent two dead horses to the University of Florida Veterinary Medical Center to conduct necropsies, but those reports failed to find an apparent cause of what sickened the horses.

The farm, on South County Road 475, is an embryo transfer facility in which Davila takes fertilized eggs from donor horses and implants them in surrogate horses.

Davila said he doesn't know the financial loss due to the disease, but estimates it to be in excess of several hundred thousand dollars. He said his horses are insured.

The couple said that the suspect hay arrived Sept. 26 and 27 and that by Sept. 28, the first few horses became sick.

"When we saw two or three, that wasn't common," Davila said.

Within hours, the couple said many more horses showed neurological problems, including twitching muscles, inability to stand and seizure-like symptoms.

Davila and Ramirez contacted other local veterinarians to help treat the horses and rid the animals of potential toxins in their stomachs.

By last Friday, antitoxins had also arrived from the University of Florida veterinary college, which the farm used to treat the sick horses, Davila said. EquiTransfer also gave the antitoxin to its healthy horses as a precaution.

There are at least 400 horses on the farm.

Davila said he is not sure whether the treatments worked, or whether horses got better on their own.

When the disease was at its worst on the farm, horses were "dropping like flies," he said. A few horses could still begin to show symptoms of the disease, but most appear healthy now, Ramirez said.

Davila said soon after his horses started dying he informed veterinarian Mike Short, with the state veterinarian's office, which is part of the Florida Department of Agriculture and Consumer Services.

"If you look at what's occurred, there's no evidence it was contagious," Short said Thursday. "It looks like it's mostly associated with hay."

The death of so many horses on a single farm because of contaminated feed, however, is something most veterinarians have never heard of.

"It sounds fairly improbable to me, but stranger things have happened," said Diane Kitchen, another state veterinarian with the Florida Department of Agriculture. "We've never heard of anything like this on these numbers."

Carol Clark, a veterinarian with Peterson & Smith Equine Hospital in Ocala, said the most likely cause was something the horses ate, but only the toxicology tests would be able to show what made the horses die.

Clark said there were many ways hay can become contaminated.

Poor storage of hay can cause mold contamination, she said, but added that toxins in mold generally do not cause the kinds of problems EquiTransfer saw with its horses.

If dead animals are accidentally wrapped into the hay, that could also contaminate it, she said. But that would contaminate only the single bail, not all the other bails delivered to the farm, she said.

Another culprit could be botulism, Clark said.

In the case of botulism, the bacteria Clostridium botulinum produces spores which sticks to the hay when it is cut and baled. The spores become bacteria, which produce a deadly toxin.

The bacteria thrive in environments absent of oxygen.

In some cases, grass that is cut and wrapped and allowed to ferment, which is conducive to the deadly bacteria's growth if not handled correctly, Clark said.

The processed hay is called haylage and is typically given to cattle because cattle are less susceptible to botulism, Clark said.

Horses are highly susceptible to the disease and many veterinarians, including Clark, due not recommend haylage be given to horses.

Davila said the hay he gave his sick horses was haylage, but that it was inoculated to make it safe for horses.

It is unlikely state animal officials will get involved to ensure the supplier's hay, if any is left, is not sold to another farm, though.

That's because Steve Dwinell, a Florida Department of Agricultural official, said the state only regulates animal feed, not hay. Feed includes supplements such as protein mixes, hay is essentially dried grass.

"There has to be evidence of some regulated commodity'' for the state to investigate, Dwindell said. "[Hay] is not considered a regulated feed."

There have been four complaints from citizens made with Marion County Animal Control against the farm since 2005, county records show. When Animal Control investigators visited the site, they found the complaints unfounded and the horses well-fed and healthy.

As for the farm's latest problems, the department's spokeswoman, Christy Jergens, said, "As of right now, there doesn't look to be any legal problems. If something else is found, that could be a different situation."

Fred Hiers may be reached at fred.hiers@starbanner.com or 867-4157.