To reduce the number of dairy and beef cattle infected with the bovine leukemia virus in the United States, veterinarians like Dr. Bob Judd are encouraging ranchers and dairymen to test their cattle and take the necessary precautions to prevent spread of the disease.
On his show, Texas Vet News on the Texas Farm Bureau (TFB) Radio Network, Judd discusses a recent article by Dr. Lew Strickland of the University of Tennessee that indicates 44 percent of dairy cattle and 10 percent of beef cattle in the U.S. are infected with the virus.
“Clinical signs do not usually appear until the cow is five or six years of age. The most common methods of transmitting the virus are normal procedures including tattooing, rectal palpation and dehorning,” Dr. Judd said.
The presence of the viral infection increases with age.
An infected cow can transmit the virus directly to her fetus before birth or after the calf’s birth through the first milk.
Material that is contaminated with blood or rich in lymphocytes can be infectious to other animals.
Of those with the virus, about 5 percent will develop lymphosarcoma, which is a malignant tumor that generally causes swelling of the lymph nodes. Tumors can develop in the abdomen, spinal cord, eye, heart or reproductive tract. Symptoms depend on the location of the tumors.
There are no vaccines or treatment for the virus.
“Prevention is critical in controlling this disease,” Dr. Judd said.
Prevention includes isolating and testing all cattle before entering the herd and then again later. Dr. Judd also recommends annual testing for the virus and disinfection of tool while treating cattle.
Dr. Judd’s report can be heard here: http://bit.ly/1FUDqRA.