Anaplasma in cattle

Anaplasma is a serious disease in cattle that is spread by ticks. You may have heard it called yellow bag or yellow fever. It’s caused by the organism Anaplasma marginale which lives within red blood cells and causes severe anemia.

The disease has serious ramifications in the cattle industry because it causes weight loss, lowered milk production, abortions, treatment costs, and even death. Typically the disease affects cattle two years old and older, however, younger cattle can be carriers.

Anaplasma is becoming more common on the east coast and in Kentucky. This is a disease you should be monitoring for and call your vet if you see symptoms.

Symptoms

• Fever
• Yellow eyes
• Behavioral changes – cows become short-tempered and less docile
• Anemia – pale eyes and gums
• Weakness
• Dehydration and “off” feed
• Weightloss

How Is It Spread?

Typically, cases of anaplasmosis increase in late summer and fall as insect vectors increase. Ticks are the most common vector but biting insects such as large flies can also spread the disease.

Therefore, control of vectors is key to preventing anaplasmosis. Deer may increase tick populations however, they are not thought to spread disease.  Mowing your fields and worming animals can help control parasites on your farm.

It can also be spread by the use of veterinary instruments such as needles and veterinarian gloves that have blood on them.  It is very important when vaccinating cattle to change the needle for EVERY cow. This is not a time to be cheap.

Recently evidence for intrauterine transmission (from cow to calf during pregnancy) was recognized and may lead to fetal death and abortion. 

Check out Dr. Glaza’s podcast on Vet Talk about Bovine Anaplasma.

The incubation time averages two to three weeks before you see signs of the disease. However, some cows will incubate the disease up to four months before showing symptoms.

The disease is generally mild in young calves up to two years old. They may show no symptoms but can be carriers. That means they can spread the disease to others via a tick or other biting insect.

Cows over age two can get severe causes that lead to death. Even if the cow receives treatment or recovers naturally they are still a carrier.

Treatment

Tetracycline is often used for clinical anaplasmosis but is not always effective. If necessary herd treatment with oxytetracycline injection every 3 to 4 weeks during high-risk times.

There are feeds that contain oxytetracycline but Dr. Glaza does not recommend these. Overfeeding of antibiotics can cause resistance to these life-saving drugs. Also, it will not prevent cattle from carrying and possibly spreading the disease.

There is an experimental vaccine available for anaplasmosis. The vaccine was developed by veterinarian Dr. Gene Luther. Dr. Glaza can get the vaccine into the clinic. This annual vaccine will help you protect your herd.

Give the office a call at 859-472-4141 to learn more about vaccinating your herd.

Author, Ame Vanorio, is the director of Fox Run Environmental Education Center and a licensed wildlife rehabilitator. She teaches onsite and online classes in organic gardening, solar power, and wildlife rehabilitation. She lives on her farm in Falmouth, Kentucky with too many animals to count!