Twenty-two per cent of the 1728 horses so far tested for equine piroplasmosis have return positive results, the Texas Animal Health Commission says.
Equine piroplasmosis, a tick-borne protozoal infection of horses, was first detected in October 2009 on a south Texas ranch.
The commission has also confirmed that at least one species of tick, Amblyomma cajennense, has proven capable of transmitting the blood parasite. This species of tick is endemic to South Texas and several other southern states.
"Further research is under way to determine if there are other tick species capable of transmitting the parasite," the commission said.
"The disease may also be spread between horses by unsafe animal husbandry practices such as sharing needles or equipment that is contaminated with blood."
Dr Dee Ellis, who is Texas state veterinarian and also executive director of the commission, said: "Field personnel are still investigating how many animals may have been exposed or infected with this disease."
In almost every case, the positive horses were directly traced to the index ranch in Kleberg County or had contact with positive horses from the ranch.
Ellis said that because of that fact, there did not appear to be a geographic correlation to the presence of the disease, but rather a correlation to exposure with positive horses.
"This is not a widespread South Texas outbreak," he said.
While piroplasmosis can be fatal, many horses may display vague signs of illness, such as fever, lack of appetite or jaundice.
Local horse owners are advised to consult a private veterinarian to discuss tick control, management practices, or any concerns about illness.
Several states have imposed interstate movement restrictions on horses from Texas.
The commission and staff from the US Department of Agriculture are continuing to trace, identify and test animals on a prioritised basis.
The priorities include:
- "Direct traces" of horses that lived on the ranch.
- "Dangerous contacts", which are horses that visited the ranch, or whose dam was infected.
- "Cohorts", which are horses that have lived with positive animals.
At this time, horses living on premises adjacent to the index ranch are being tested on a voluntary basis only, since this does not appear to be a geographic outbreak.
In January, the commission hosted a meeting with 32 representatives from 20 Texas equine industry groups to discuss the status of piroplasmosis in the state.
Risk procedures for positive and exposed horses were discussed, and input sought on how the state should further respond in terms of surveillance, movement requirements, and identification of positive horses.
Facebook
Twitter
HOME SITES 
