Anaplasmosis is caused by bacteria generally spread by ticks affecting ruminants, dogs, and horses. It is infectious but not a contagious disease. Anaplasmosis infects red blood cells causing fever and anemia. Bovine anaplasmosis is usually caused by Anaplasma marginale. Up to 17 different tick species can transmit the bacterium. Dermacentor spp. are the main vectors in the USA; however, the use of contaminated needles or other surgical instruments may also spread anaplasmosis.

Clinical signs have a strong correlation to the age of cattle and severity of the disease:

• Less than one year of age = usually subclinical
• 1-2 years of age = moderately severe
• Older cattle = severe and often fatal

Cattle that die from anaplasmosis generally have pronounced anemia and jaundice. Blood is thin, watery, and the spleen is enlarged and soft. There are serous effusions in the body cavities, pulmonary edema, and petechial hemorrhages of the endocardium. Diagnosis and testing are accomplished through clinical signs/history as well as serological testing, and blood smears. Early treatment with tetracycline drugs usually will ensure survival in the early stages of acute disease.

Awareness and prevention of Anaplasma is best accomplished through good biosecurity practices such as:

• Stringent control or elimination of tick vectors - limiting ticks with acaricides
• Animal management practices - introducing animals to infected pastures at an age when less apt to develop severe clinical symptoms

Best practices for needle selection, use and care in cattle health