By MEGGIE I. FOSTER
Assistant Editor INDIANAPOLIS, Ind. — For most Midwest horse enthusiasts summer signals the onset of local shows, trail riding excursions and outdoor festivities. Unfortunately the joys of the season shares some pesky, uninvited and disease carrying company … horseflies.
And not only are these biting creatures just a pest to horses, but they also carry the deadly threat of spreading equine infectious anemia (EIA) to horses, mules and donkeys across the country. EIA, also known as swamp fever, mountain fever or malarial fever, is an untreatable and incurable viral disease that infects all types of equine. An estimated 30 percent to 50 percent of infected equine die within two to four weeks of the onset of EIA.
In a recent cautionary announcement by the Indiana Board of Animal Health (BOAH), Dr. Tim Bartlett, a veterinarian and director of equine for BOAH encouraged horse owners and veterinarians to observe their horses, mules, donkeys and other equine closely for any unusual disease symptoms in light of a cluster of recent positive cases of EIA in southern Indiana.
According to Bartlett, three horses on a south-central farm recently tested positive for the lethal disease. In a May 28 press release, he confirmed that state and federal veterinarians have been working vigorously with the owner to identify the source of infection and determine if any other animals are at risk. All three positives have been euthanized; two herd mates have tested negative and remain under quarantine until further testing is complete.
“EIA is thankfully not very common in Indiana, it’s really the southern part of the United States that is the hotbed for the disease,” said Carol Habig, an equine practitioner in central Indiana and a member of the board of directors for the Indiana Horse Council, who added that in her 28 years as a practitioner “I have never had a positive case of EIA in my entire career.”
Even while rare in Indiana, depending on an individual horse’s immune system and the severity of its reaction, EIA symptoms can range from virtually none at all to weakness, weight loss and swelling to fever, rejection of feed and sudden death. A blood test, often referred to as a Coggins’ test, can detect the infection.
However, Bartlett cautioned that Coggins’ test results can sometimes produce a false negative up to 42 days after exposure to the disease.
Preventative measures Bartlett explained that the fatal disease is spread to other equine via blood-to-blood transmission, not through casual contact with other horses.
“Blood transfusions, unsterilized or contaminated needles and medical instruments can transmit the virus,” he stated. However, “horse owners should be most concerned about biting insects – especially horse flies – which can spread the disease.
“Research shows that as few as three horseflies can carry enough virus from one animal to another to cause an infection. That’s why pest control is critical to the control of this disease,” concluded Bartlett.
Additionally, Habig precluded to the rare situation of a “latent carrier,” which is an infected equine that shows no clinical symptoms of the disease.
“A latent carrier can certainly affect healthy horses and can be a dangerous source of spreading the deadly disease,” Habig explained. “He’s like the bank that holds all the money, when a fly bites him, then another horse, he’s able to spread the disease. With EIA, a horse may get sick or just be a carrier. That is why it is so important to Coggins’ test.”
Bartlett also advises equine owners to minimize the chances of EIA entering their herds through the extensive testing of newly purchased animals.
“All equine should be tested for EIA before being brought onto a farm,” he warned. “Then, the animal should be isolated and observed for 45 days to 60 days, then retested before it is introduced to the herd.”
Legally speaking, Bartlett mentioned that state law requires all equine entering Indiana must have a health certificate indicating a negative EIA test within the previous 12 months. Suckling foals, accompanied by an EIA-negative dam, are exempt from testing, he added.
To protect Indiana’s healthy equine population, if a horse or other equine tests positive for the disease, the animal must be permanently identified with “32A” freeze-branded on the left side of the neck to comply with state law. This permanent identification helps to protect healthy, tested equine and eliminates the confusion about health status.
Also, if tests return positive, the owner is faced with two unfortunate options for handling the horse. One option is to permanently quarantine the animal to the owner’s premises, which require the infected animal to be at least 200 yards from the nearest equine or the owner can euthanize the animal after further notifying the state veterinarian.
For additional details about EIA to online to www.boah.in.gov |
