The EHV-1 quarantine for horses at Laurel Park and Pimlico could now continue until mid-April and racing is cancelled through April 4, racing officials said during a horsemen's teleconference on Friday. A total of 26 horses have tested positive for the virus and are now in isolation at Bowie Training Center, and another 10 horses are suspected to have the virus but awaiting test results. Most of those horses have come from Laurel Park, but Pimlico has also had one positive with test results pending on another horse.
Veterinarians with The Stronach Group and state health officials described a shift in procedures for testing and quarantine as the situation has continued to evolve from the first EHV-1 positive at Laurel in early March. There are two schools of thought on the best testing procedures in EHV-1 outbreaks: one that suggests testing all potentially exposed horses and releasing them after two weeks if they test negative and show no symptoms. The other suggests a 21 to 28-day quarantine for exposed horses, and testing only of symptomatic horses. Initially, officials took the 14-day approach but quickly found a high number of positives from asymptomatic horses.
Dr. Dionne Benson, chief veterinary officer for 1/ST RACING, said Friday that some 30 percent of the population is expected to be shedding the virus at any given time while having no illness. Most veterinarians agree that horses are commonly exposed to equine herpesvirus but for whatever reason, many never actually get sick from it. Horses who are sick and shedding the virus through their nasal secretions are releasing much greater amounts of the virus and therefore represent a danger to others that asymptomatic carriers likely don't.
In an effort to avoid quarantining the track over asymptomatic positive horses, veterinarians have now swapped their strategy to the 21-day plan, and say they need cooperation from horsemen to make this as efficient as possible. Trainers are asked to take horses' temperatures frequently and report any horse with a temperature of 101.5 or higher, or any horse exhibiting neurological symptoms. Those horses will be isolated immediately and tested.
In several cases, Benson said symptomatic horses have been removed from their home barns and tested negative at first sampling, then been positive on a second test taken a few days later. This means those horses were not shedding the virus at the beginning of their illness when they were in their barns, but began to do so in isolation as their illnesses progressed. In those cases, officials are not shutting down the barns those horses came from because they believe those horses weren't yet contagious when they last saw their stablemates.
Currently, confirmed positives are being sent to Bowie, where they can spread out across barns in different areas of the facility. “Suspect horses,” or those with symptoms, are being moved to designated isolation barns at their home track (either Laurel or Pimlico) to wait out test results. If feverish horses return two negative tests, they can return to their home barn because their fevers are likely caused by something other than EHV-1. EHV-1 is highly contagious and can be transmitted not just from horse-to-horse contact, but by people and equipment that travel between horses.
Training schedules have been disrupted at Laurel as officials try to keep horses from potentially-contaminated barns apart from the rest of the population, although Benson said it's extremely unlikely a horse could catch EHV-1 by jogging by an infected horse on the track. Horses that have been potentially exposed but are not ill are allowed to train because veterinarians believe the stress of three weeks of stall rest could make them more susceptible to developing symptoms.
If there are no more positives at Laurel, the quarantine could be released April 17. If the pending test at Pimlico is negative, its quarantine will be released 21 days from the first positive, which would be April 12. If the current pending test is positive, Pimlico will also be released April 17.
Veterinary officials said that contact tracing has been performed on all horses that left the Laurel grounds before the gates were closed at the start of March with the first detected EHV-1 case. No other cases have been reported in connection with Laurel's outbreak.
The Mid-Atlantic circuit is known for lots of horse travel up and down the East Coast, and owners and trainers on Friday's teleconference indicated they're losing significant revenue by being forced to remain at Laurel. Even if they were permitted to leave, Benson pointed out most other racetracks would not permit a horse to come in from a Maryland track right now. It is possible for trainers to get special permission from state veterinarian Dr. Mike Odian to send horses to a local farm, but they will be required to quarantine for 21 days there.
The EHV-1 strain in Laurel's outbreak is the “wild” type, which means it's not the same version of the virus making headlines in Europe right now, or the same version that's been found in Florida. While there is a vaccination for equine herpesvirus, it is not approved as a means of preventing the neurological form of the illness.
As everyone waits out the quarantine, there is one thing horsemen can do to help the situation, besides following all biosecurity protocols: open the barns. EHV-1 is thought to thrive in closed environments and creates infections when there's a lot of it in a concentrated amount of air space. Getting circulation through the barn will dissipate the virus and make it less likely a horse can get sick.
The post Maryland: EHV-1 Positives Up To 26, Racing Cancelled Next Weekend appeared first on Horse Racing News | Paulick Report.
