Ask the Vet

Cattle Fever Concerns

Cattle fever ticks carry a disease that once devastated herds in the 1800s and 1900s. (Photo courtesy BeaJai Merriman)

QUESTION:

In an earlier column, you mentioned Texas cattle fever and said it could become a problem in the U.S. I have never heard of this disease. What do I need to know to protect my herd?

ANSWER:

Texas cattle fever is a disease caused by the protozoa, or single-celled parasites, Babesia bovis or B. bigemina. The disease is carried by Cattle Fever ticks (Rhipicephalus annulatus and R. microplus). This was a devastating disease in the 1800s and early 1900s. The ticks and the disease spread into the Midwest and the South with the great cattle drives of the time.

Babesia destroy red blood cells causing acute anemia. Cattle run a high fever, are depressed and lose weight. In groups of cattle that have never been exposed to the disease, death loss can run up to 90%.

An aggressive, controlled program including dipping cattle in huge vats essentially eradicated the ticks and the disease by 1943. A buffer zone was established along the border with Mexico to prevent reintroduction. Researchers now feel deer are capable of carrying these ticks, which complicates prevention for cattle producers. Our biggest concern now is that the U.S. cattle population has never been exposed to this disease and has no natural immunity. This means effective tick-control programs will almost certainly become much more important in the future.

Write Dr. Ken McMillan at Ask The Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email vet@progressivefarmer.com.

(SK)