The blood disease anaplasmosis could surface in cattle herds this fall, and producers should keep a watchful eye on animals. The disease, which causes severe and potentially fatal anemia in cattle but poses no threat to humans, is caused by the parasites Anaplasma marginale and Anaplasma centrale.
“If you have, or suspect anaplasmosis, work closely with your herd veterinarian to develop effective treatment and control programs,” says Purdue veterinarian and clinical assistant professor of veterinary medicine Bethany Funnell. “Death of an adult is often the first sign noticed in a herd infection.”
Symptoms in cattle include weight loss, loss of appetite, high fever, dehydration, constipation, pale mucous membranes inside eyelid and vulva, jaundice, abortion in pregnant cows and aggressive behavior. The disease is more common among middle-aged animals, with most fatal cases occurring between 6 and 8 years old.
Anaplasmosis in cattle is spread by parasites such as biting flies and wood ticks. Wet weather in the spring may have created ideal breeding conditions for the insects that carry the disease.
Herds may also become infected by de-horning, ear-tagging, castration, injection and other equipment that has not been disinfected between uses on different cows.
The disease is found in both beef and dairy herds but is less common in dairy herds.
Early treatment of the disease is key to keeping cattle alive. Funnell recommends that producers in high and moderate infection areas consider vaccinating young cattle against anaplasmosis because symptoms are often not seen in cattle younger than a year old.
Funnell said clearing infection requires long-term antibiotic therapy, and producers should consult their herd veterinarians to decide on an appropriate course.