Johne’s disease is a herd problem because when one animal shows clinical signs in a herd, then probably more animals are infected.

Animals most commonly affected are cattle, sheep, and goats. However, Johne’s disease has also been reported in deer, elk, and antelope, as well as a few isolated cases in pigs, horses, chickens, llamas, and nonhuman primates.

The disease generally enters a herd when an infected, healthy animal enters.

The manure of infected animals is the most common source of infection to other animals, and clinically infected animals shed high numbers of organisms. The organisms don’t multiple in the environment but they can survive for over a year because of their resistance to heat, cold, and drying.

Animals become infected most commonly by ingestion of the bacteria, through sucking on manure-contaminated teats, licking contaminated equipment, consuming manure contaminated feed or drinking water. Transmission of the bacteria is also possible through the colostrum and milk of infected cows. Occasionally a fetus may become infected if the mother is in the later stages of disease.

Usually, clinical signs of disease are not obvious until the animal is mature (3-6 years of age), even though infection usually occurred during the first few months of life. Cattle become more resistant to infection with age.

Cattle with Johne’s disease have a long-lasting diarrhea and lose weight, despite a good appetite. Some infected animals are unthrifty and weak and may have bottle jaw (fluid under the jaw), whereas, others just have a chronic diarrhea. Signs of disease may occur within a few weeks after a stressful event, such as calving.

The disease may be recognized in a herd by: 1) clinical signs of weight loss and chronic diarrhea in cows with a good appetite, 2) a history of low herd production, and 3) culture of the organisms in the feces, blood, or colostrum (success of culture depends on animal’s age and stage of infection).

Currently, there is no treatment in cattle that will cure infected or sick animals.

Currently, there is no vaccine available in Canada that prevents Johne’s infection.

Johne’s disease can be prevented, controlled and even eliminated in infected herds by applying critical management points that are based on the understanding of the disease. A typical herd control program may take 5 years or longer.

Prevent infections by acquiring cattle from test-negative herds or pre-testing mature cow additions.

Control Johne’s disease by manure management.

Provide clean water by using water troughs or restricted access to waterways.

Provide clean feed by feeding off of the ground.

Divert manure runoff from water sources.

Provide clean, well-bedded, and spacious calving areas. Move cow/calf pairs to a clean nursing area as soon as possible. Have separate calving and hospital areas.

Remove newborn calves from infected dams.

Feed colostrum from negative cows.

Cull clinically infected animals as soon as possible and segregate them from others until they are culled.

Carry out a testing strategy i.e. at pregnancy exam or vaccination time, to identify subclinically infected animals, and then cull, segregate, or manage them to reduce exposure to others.

Transport cattle in clean livestock trucks.

Contact your herd veterinarian for more information.