Every Fall, cases of anaplasmosis crop up across the country. As you prepare for the season, we thought it would be helpful to provide you with the top 5 things you should know about the disease in case it rears its ugly head again this year.


  1. It is caused by a bacterial organism that infects the red blood cells, but it doesn’t directly cause damage to the red blood cells. Rather, it causes the body to recognize the red blood cells as foreign and the animal’s body itself kills the infected cells, causing anemia. This results in a lack of ability to transport oxygen, so the organs and tissues fail. Initially, affected cattle may simply be noticed standing off alone or not coming up to feed. Occasionally, an animal is found down and unable to get up or is simply found dead. Middle aged to older cattle are more often affected than young. In the photo accompanying this article, you will see an arrow pointing to a purple dot inside a red blood cell. That purple dot is the Anaplasma sp. organism.
  2. It is transmitted by blood-sucking flies and ticks. It can also be transmitted by needles and other processing equipment. Measures can be taken to control ticks and bloodsucking flies, but it’s nearly impossible to eliminate these as contributors of risk. It is, however, within our power to control the transmission our equipment causes. Disinfecting castration knives, dehorners, tattooing pliers and other equipment that contacts blood can stop transmission from one animal to the next. Changing needles after every animal is perhaps the most important control measure. Research has shown that, after contacting blood from an infected steer, a single needle is able to infect animals up to the 10th animal through the chute after.
  3. Treatment can be successful. This organism can be killed by antibiotics in the class of tetracyclines, such as oxytetracycline. Early recognition of the disease provides the best opportunity for successful treatment. If you suspect anaplasmosis, call your veterinarian for a treatment plan, which may include other supportive care besides antibiotics. For cattle who are severely affected, weak, or down, the prognosis for recovery is poor.
  4. A critical component in the recovery of any animal from anaplasmosis is that they be handled quietly and calmly. Any sudden stress can cause them to decompensate for the lack of oxygen in their blood and they can die instantly. When attempting to get cattle up to treat them, they should be walked very slowly and quietly. I actually recommend to my clients whose herds have had a history of anaplasmosis that, if they ever find a weak or down cow, they approach her slowly and look at the color of the corners of her eyes or the inside of her vulva (for bulls, the inner portion of the sheath works in all but black bulls). If the color is very white or has a yellowish tinge, anaplasmosis could very likely be the problem. Then, when they call me, I know that this is an animal that perhaps I should have the owner treat himself/herself because if I drive up as a stranger in a strange truck, I may cause more harm than good. This is a great example of a situation where an active, engaged relationship with your veterinarian can be extremely helpful.
  5. Prevention is possible through insect and tick control and proper needle and equipment management but there is more that can be done. There are products that can be used in feed to reduce the numbers of organisms in the blood and prevent disease. New regulations enacted in 2017 now require a Veterinary Feed Directive (similar to a prescription) from your veterinarian in order to use these. It’s worth a conversation with your veterinarian about your herd’s risk level for anaplasmosis to decide what types of preventative measures make the most sense for you.
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