Diseases of Cattle: BRUCELLOSIS

Brucellosis of cattle, also known as "contagious abortion" and "Bangs disease", is caused by infection with the bacterium Brucella abortus, which can also cause a disease of humans known as "undulant fever".  Brucellosis infection of cattle causes abortion or premature calving of recently infected animals, most often between the fifth and eight month of pregancy.  Although federal and state regulations have helped to control this disease, there is still a threat.  Infected cows frequently suffer from retained afterbirth, are difficult to get rebred and sometimes become sterile.   

Brucellosis is spread from the vaginal discharge of an infected cow or from an aborted fetus.  The organism has an affinity for the reproductive tract and abortions, retained placenta, weak calves and infertility frequently occur.   Breeding bulls which are infected, can transmit the disease to cows at the time of service by infected semen.  Milk produced front an infected cow may also harbor the organism.  The infected milk creates a public health hazard as this is the organism that causes undulant fever in humans.

There is no treatment for Brucellosis. Prevention of Brucellosis is accomplished by official calfhood vaccination of heifer calves.  Vaccination must be done by an accredited veterinarian at calf ages that vary from two to four months using standard dosage vaccine, or from 4 to 12 months using reduced dosage vaccine.  Each calf must be identified as officially vaccinated in compliance with state and federal regulations.  Quarantines are imposed on infected herds by state and federal authorities until the herd has been proven free of the disease.