It is difficult to quantify the risk of anaplasmosis in any given herd in any given time of year, but when an outbreak occurs, it can result in devastating consequences for a cow/calf herd. Daniel Scruggs, DVM, managing veterinarian with Zoetis, offers some tips for cattle producers to reduce the risk of anaplasmosis, and what treatment options are available to them.

Anaplasmosis is most commonly caused by Anaplasma marginale, a microorganism that invades red blood cells, causing severe anemia. The disease is often spread through hosts like biting flies and ticks that transfer blood between animals. Contaminated needles or other equipment can also cause anaplasmosis.

The disease can result in aborted calves, bull infertility, weight loss and diminished milk production, and also has the potential to be fatal. Mixing noninfected cattle with those that carry the disease, as well as environmental conditions that favor increased activity of biting flies or ticks, both contribute to an increased risk for the disease.

“Anaplasmosis is sporadic, not all factors that cause outbreaks in a herd are known but when they occur, consequences can be significant,” said Scruggs.

Mature animals have higher susceptibility to the disease than younger animals, and cows in the late stage of pregnancy and those nursing calves have particularly high death loss.

Signs of anaplasmosis can include orange-yellow coloration of the mucous membranes, thin, watery blood, slow, reluctant to move or short of breath cattle, aggressive behavior shortly before death, sudden, unexplained death of adult cattle, and abortions.

One of the most commonly used methods for the control of anaplasmosis is the incorporation of a feed-grade chlortetracycline, such as Aureomycin, in the animal’s feed or mineral supplements. Administration can occur year-round in feed or minerals in regions where fleas and ticks are active year-round, but producers in other areas often focus on late spring through fall, the time of highest transmission. More information on Aureomycin can be found here .

“It’s really a factor of diligence in making sure cattle are protected,” Dr. Scruggs said. “With spring-calving herds, the bulls are out during the spring and summer vector season. When bulls are experiencing an acute infection of anaplasmosis, and they become anemic or dead, they’re not good at settling cows. Whether a producer is running a spring-calving or fall-calving herd, there’s never a good time to go to sleep on anaplasmosis control.”

For more information on controlling anaplasmosis, contact your veterinarian, feed company nutritionist or Zoetis representative.