Worst appears to be over in Churchill herpesvirus outbreak

It is not over until it is over, but the equine-herpesvirus outbreak that hit the backstretch at Churchill Downs is “trending in the right direction.”

That was how veterinarian Dr. Will Farmer, the equine medical director for Churchill Downs Inc., characterized the flare-up that began two weeks ago when a filly in the barn of trainer Saffie Joseph Jr. tested positive. So then did five other horses in nearby stalls, triggering a quarantine.

“Four of those five have been released,” Farmer told Horse Racing Nation on Wednesday morning. “One of the original five and one additional horse that tested positive last week are still under quarantine from direct exposure.”

Those horses did not include the first filly, whom Joseph said Tuesday was improving.

“She’s doing better,” Joseph said. “She’s still at the clinic (in Lexington, Ky.), but we expect her to be released soon.”

About 45 horses still under a precautionary quarantine have to stay put until Dec. 28.

“Barns 36 and 38 remain under quarantine through indirect exposure,” Farmer said. “Again, no issues to report there. Everybody has been healthy. No big changes there. Barn 37, which houses three of the original negatives, are still there. They were not retested.”

Farmer said the wide expanse of the Churchill Downs stables helped his team get its arms wrapped around the outbreak.

“We had the space to help separate these horses out by trainer, which allowed us to get the horses cleared a little bit quicker,” he said. “That was a huge help to be able to have the luxury of space to do that.”

Another round of testing Tuesday confirmed the EHV-1 cases may have peaked at seven.

“Those tests were beneficial,” Farmer said. “Horses that either had previously tested positive through our initial testing two weeks ago had become negative and had remained asymptomatic from beginning to end. The horses that had tested negative initially again were confirmed negative.”

The additional case mentioned by Farmer crossed his radar last week.

“We did have one horse that had a very slight positive on a nasal swab last Tuesday,” he said. “Asymptomatic. No fever. Nothing. We did isolate that horse. The trainer hasn’t decided if they’re going to test or if they’re just going to hold out on it and wait to go to the 28-day mark. That horse was not retested this week.”

Without mentioning names, Farmer said three trainers and “close to 50” horses were affected at the peak of the outbreak.

Wakanaka, a filly trained by Bill Mott and shipped from Churchill Downs, was scratched from the Dec. 4 running of the Matriarch Stakes (G1) at Del Mar after she was confirmed to have caught the herpesvirus. That was the only known case of a shipper from Kentucky testing positive this month for EHV-1.

Two other noteworthy outbreaks of the herpesvirus in March were contained within three weeks at Parx Racing in Pennsylvania and Fonner Park in Nebraska.