Johne's Disease: Chronic Debilitating Disease of Cattle

Assistance is available for cattle producers to control a costly illness in their herds, Johne's Disease (JD). The Colorado Department of Agriculture received a grant through the U.S. Department of Agriculture to help cow-calf and dairy producers with risk assessments, management plans and tests for the disease.

"Johne's Disease is extremely hard to control because of the long period before infected animals develop clinical signs or test positive for the disease," said Ron Ackerman, veterinarian at the Colorado Department of Agriculture. "In fact, some herd owners may never recognize that their herds are infected."

The disease is expensive for producers, since it causes lower milk production and lighter calves at weaning. Infected cows will stop cycling and will not breed back. The disease causes premature culling of infected cattle and can result in the loss of valuable genetics from some herds as well as higher replacement costs. Some studies have found that the cost per cow is as high as $200 in purebred herds.

Grant funds will help with conducting a risk assessment of herd practices, usually by the local veterinarian, that permit the introduction and spread of the disease. Recommendations will be provided to best reduce or eliminate the identified risks.

Once a risk assessment and herd management plan is completed, the producer can begin testing for the disease.

"Many producers and veterinarians have a natural tendency to want to go to the testing component first," said Ackerman. "However, testing and culling positive animals without management changes will never eliminate this disease from a herd. Infected cattle will test negative for long periods while exposing young cattle to massive numbers of the bacteria before they are identified and removed from the herd."

Newborn calves are the most susceptible to Johne's Disease. The disease is most commonly transmitted when an animal eats contaminated feces, found on dirty teats, udders and soiled feed. Calves can also catch the disease when they nurse from infected cows, since the bacterium is shed in the colostrum and milk. Up to 40 percent of the calves from infected cows, which are also exhibiting clinical signs, are infected before they are born.

"The information we have on Johne's Disease is not as well researched for beef cattle as it is for dairy cattle," said Ackerman. "Even though there have been fewer studies, the U.S. Department of Agriculture's National Animal Health Monitoring System completed a beef study in 1997 that found 7.9 percent of the tested beef herds had a significant number of infected animals."

Johne's Disease, which has been is U.S. herds since 1908, has a long incubation period of two to five years, possibly even longer. Clinical signs include chronic diarrhea and weight loss even though the animals maintain a good appetite because the disease attacks the lining of the small intestine, interfering with the absorption of nutrients. Before the infection spreads throughout the animals' bodies, they appear bright, alert and have a normal temperature. Eventually cattle become severely emaciated and die.

In 2002, the Colorado Voluntary Bovine Johne's Disease Control Program was developed to educate livestock producers about the disease and give them the tools to prevent, control and eliminate the disease from their livestock operation.

The Johne's Advisory Committee, which created the program, includes practicing veterinarians, livestock producers, Colorado State University faculty, and government officials with the U.S. Department of Agriculture and the Colorado Department of Agriculture.
Contact Ron Ackerman at (303) 882-2753 for more information about the Johne's program or to enroll your herd.