The investigation into equine piroplasmosis in Florida is ongoing. The state’s Department of Agriculture and Consumer Services released a statement Aug. 28 indicating that 11 premises have thus far been quarantined and more than 90 horses tested.

Horses on two premises have tested positive for the disease. Four horses at the home barn of the horse that first showed clinical signs have tested positive, along with one horse at a property in DeSoto County. The DeSoto County horse had a direct link to the horses at the original farm.

According to Mike Short, DVM, equine programs manager for Florida’s Division of Animal Industry, horses were traded back and forth between these two properties. At least two of the horses from the first property stayed at the contact farm for training.

Short said officials are investigating other properties as well.

“We’ve got samples pending from a couple other premises that just have horses linked to the index premises,” Short said.

While Short said it still appears that shared needles are the most likely mode of transmission in these cases, tick surveillance continues to be a large part of the disease response.

Thus far investigators have not found any of the tick species that are known to carry the organisms that causes equine piroplasmosis, Babesia caballi and B. equi. Short said that if they find any tick species that are able to carry the parasites, the ticks will be tested using polymerase chain reaction (PCR) to see if they’re carrying any DNA of the organism.

Right now the question remains where these horses–and, thus, piroplasmosis–came from.

Short said officials are still working with the horses’ owners to get full histories on the animals, which are Quarter Horses that had been running on local “brush track” racing circuits. Some of these horses were purchased off of sanctioned Quarter Horse circuits. In these cases, investigators have a leg-up, in that they can correlate the owner’s recollections to the horses’ official race records.

“I can tell you the tattoos are helping us a lot,” Short said. “Most of these horses they’re racing are directly off Quarter Horse tracks, so we can use that to confirm what they’re telling us.

“We’re trying to do trace-outs and find any links, and really direct epidemiological connections to these positive horses. (We’re) following those out and getting those horses quarantined and tested, and trying to get good histories on those horses to find out where they came from and what the source might be–where the initial infection came from,” Short said.

No states have restricted movement of Florida horses, but Canada has said it will not accept horses originating from Manatee County.

While the investigation continues, Short said he doesn’t think Florida horse owners have any reason to panic.

“I don’t think they need to be really concerned,” Short said. “I think the risk of other diseases is much more significant than this–Eastern equine encephalitis, which we’re seeing a decent amount of cases here in Florida, and all those other diseases that are endemic. Horses are at much more of a risk (of those diseases) of than this. But when you have something new, I understand their concern.

“I think we’re going to be okay, but it just depends on what we turn up. If there’s a lot of ticks or certainly an exotic tick, or if we get a bunch of premises with positive animals, then it could be bad news for Florida, but we’re just going to do the best we can do, be honest about it, and see what happens,” Short said