Short answers to common questions. For more detail, choose a specific topic. What is Johne's disease and what kind of animals get Johne's disease? What causes Johne's disease? What are the signs of Johne's disease and how can I tell if my deer/elk have it? How common is Johne's disease in deer/elk? How do deer/elk get Johne's disease? How can you prevent deer/elk from getting Johne's disease? How do you test deer/elk for Johne's disease? Can Johne's disease be cured with antibiotics? Can humans get Johne's disease?		General Dairy Beef Goats Sheep Elk Bison Wildlife

What is Johne's disease and can deer or elk get it?

Johne's (pronounced "YO-nees") disease is a contagious, slowly developing and fatal bacterial disease of the intestinal tract. A German veterinarian first described it in a dairy cow in 1895 and the disease was named after him. The disease is also called paratuberculosis. Johne's disease primarily occurs in domestic and wild ruminant species such as sheep, goats, cattle, deer/elk , bison etc. It has also infrequently been reported in non-ruminant species e.g. rabbits, primates, fox and stoat.

What causes Johne's disease?

The bacterium that causes Johne's disease is named Mycobacterium avium subspecies paratuberculosis. The name is abbreviated M. a. paratuberculosis or M. paratuberculosis. It is in the same family as the bacterium that causes tuberculosis in humans (M. tuberculosis) and animals (M. bovis). The type of disease it causes shares some characteristics with tuberculosis: it is slow to develop, it is resistant to antibiotics and is contagious. M. paratuberculosis can replicate only when within the animal; it cannot multiply in the environment. However, the hardy bacterium reportedly can survive, still infectious, in soil or water for over a year because of its resistance to heat, cold and drying.

What are the signs of Johne's disease and how can I tell if my deer/elk have it?

This disease is hard to detect in some stages. The signs of Johne's disease are vague and months can pass after infection before they appear. Weight loss in animals with a good appetite and adequate rations may be the only indication. Diarrhea, a common sign for cattle with Johne's disease, may not occur in cervid species. The signs of Johne's disease can be confused with the clinical indications of other conditions such as parasitism, malnutrition or other chronic diseases. Because of the slowly progressive nature of the infection, signs of Johne's disease are usually not seen until animals are adults, although a number of cases of yearling deer/elk dying from this infection have been reported.

How common is Johne's disease in deer/elk?

Knowledge on the prevalence of this disease is limited, due both to lack of testing and reporting. It has been described in a variety of cervid species and in most countries raising deer and elk. The prevalence is higher in farm-raised vs. free-ranging cervids.

How do deer/elk get Johne's disease?

Johne's disease typically enters a herd when an apparently healthy, but infected, animal is introduced. This animal contaminates the premises (feed, ground, water) by shedding the organism in its manure. The organism is then ingested by other deer/elk. Calves are thought to be most susceptible to infection - they can acquire the organism by suckling manure-contaminated teats and possibly from the milk/colostrum itself as the dam may shed M. paratuberculosis directly into her milk/colostrum in the later phases of the infection. If deer/elk share water and/or rangelands with dairy or beef herds that have Johne's disease, the deer/elk may acquire the infection from the cattle.

How can you prevent deer/elk from getting Johne's disease?

The best way to avoid this chronic infectious disease is to be as certain as possible that animals brought into the herd are not infected with M. paratuberculosis. Johne's disease test-negative herds are the best sources of animals for purchase. Since many herd managers do not yet test for the infection, assess the entire herd (not just the animals you intend to buy) for body condition. Ask the owner about the cull rate and common reasons for culling -how many animals were thin/unthrifty for no confirmed reason? Check the body condition of the dam of calves you intend to purchase and have her tested if you have suspicions (standard tests on elk less than one year old are not likely to be informative unless exhibiting signs of the infection).

Following general rules of sanitation are helpful in blocking transmissionof this infection. The primary goal is to prevent exposing calves to manure from adult elk. Feeders and waterers should be designed to minimize the likelihood of fecal contamination. Calving should occur in clean, dry areas. Animals with weight loss or diarrhea should be segregated from the rest of the herd and tested. Should calves be bottle-fed, ensure that the milk is pasteurized and/or comes from a goat or cow free of the infection. No Johnes disease vacine is available for deer and elk.

How do you test deer/elk for Johne's disease?

There are two common ways to test cervids for Johne's disease: culture of fecal samples and blood tests for antibodies to M. paratuberculosis. The biology of the disease can make it difficult to detect infected animals, especially those in an early stage of infection. A truly infected animal in this "sub-clinical" phase may neither be shedding the organism consistently (thus the fecal culture may be negative) nor be making antibody in response to the infection (thus the blood test will be negative). Despite the potential "false-negative" results in some cases, collecting manure for culture and/or blood for antibody tests can provide useful information needed to control the infection.

Can Johne's disease be cured with antibiotics?

Although few studies have been reported, Johne's disease is not considered a curable disease. As with most diseases caused by mycobacteria, the course of therapy is very long (months) and extremely expensive. For most animals the best that can be expected is an improvement in clinical signs while under treatment, not a cure.

Can humans get Johne's disease?

This is a very controversial subject. There is a human disease called Crohn's disease that in some ways resembles Johne's disease. The cause of this chronic inflammatory bowel disease is not known and there is no known cure. A few laboratories have grown M. paratuberculosis from a few Crohn's patients' specimens but there is no evidence that the organism caused the disease. No connection has been shown between contact with animals with Johne's disease or milk consumption and Crohn's disease.