It is a contagious, costly disease of animals that also affects humans. It is spread by direct contact with infected animals or with an environment that has been contaminated with discharges from infected animals. There were 124,000 infected herds in the United States in 1956. By 1992, this number dropped to 700 herds. On Oct. 31, 2002, there were no known affected herds remaining in the entire United States… so why should you continue to vaccinate for Brucellosis? Here are five considerations.
1. Sure, the threat of Brucellosis is low within the United States. But it is a threat nonetheless. Brucellosis is prevalent across our southern border and many foreign countries. Additionally, there is still Brucellosis within our border. The U.S. Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services National Brucellosis Surveillance Strategy of December 2010 gave a national prevalence of 0.0001 percent. The last known focus of Brucellosis abortus was in wild elk and bison in the Greater Yellowstone Area.
2. There are numerous states that do not accept dairy cattle that have not been calfhood vaccinated for Brucellosis. For best results, female calves should be vaccinated between four to six months of age. However, females may be vaccinated up to 12 months of age. Vaccination is not only an insurance policy against potential infection, but also against trade barriers. There is a perceived higher value for vaccinated heifers as compared to non-vaccinated heifers for this reason.
3. “Vaccination is just a way for veterinarians to make money.” It is true that the vaccine is only available to accredited veterinarians or state or federal animal health officials. One reason for this is that the vaccine is modified-live and poses some risk to those performing the administration. In most herds, several other activities take place during vaccination. Four to six months is a good time to do pre-breeding evaluations. What other vaccines are necessary pre-breeding? Are there any health issues that have slipped by unnoticed after weaning? Are the heifers adequate-sized? Is there a dehorning that was missed or extra teats on the developing udder?
4. Brucellosis is a zoonotic disease. This means that it can be passed from cattle to humans. The combination of pasteurization of milk and progress in the eradication of the disease in livestock has resulted in substantially few human cases than in the past. Ninety-eight cases of human Brucellosis were reported in 1997. Many of these are people who have traveled internationally and ingested unpasteurized dairy products. The dairy industry certainly does not want to be the center of a documented infection of undulant fever in the United States.
5. Orange metal ear tags are all the rage these days in the heifer lots. They are optional, however. Check with your veterinarian to see if your RFID tag will qualify as official identification.
Angela M. Daniels is a veterinarian with Circle H Headquarters LLC, a dairy and swine veterinary practice, food safety laboratory and DHIA milk-testing and contract research organization in Dalhart, Texas.