Johne’s Disease

Cow & Calves

What is Johne’s disease?

Johne’s disease (pronounced “YO – knees”) is an incurable, contagious bacterial infection which primarily affects the intestinal tract of cattle and other ruminants such as sheep, goats, deer, and elk.  Typical animals have a normal or increased appetite even as they steadily lose weight.    Chronic, long term, diarrhea is typical in infected cattle, but diarrhea is seen less often in sheep and goats.

Symptoms usually occur late in the course of disease and can mimic other diseases such as parasitism.  As Johne’s disease progresses, most cattle suffer from profuse diarrhea, extreme weight loss, and reproductive and lactation failure.  There is no effective treatment and no cure for this fatal disease, and infected animals may linger on for months as they contaminate pastures with manure containing massive numbers of bacteria.

What causes Johne’s disease?

Johne’s disease is caused by a bacteria which is sometimes called MAP (Mycobacterium paratuberculosis subspecies avium) and sometimes called Mycobacterium paratuberculosis.  Mycobacteria are a family of bacteria that can cause serious diseases such as tuberculosis and leprosy.

Johne’s disease usually spreads from older infected cattle to calves by ingestion of infected manure or milk, and calves are sometimes infected in the womb before birth.  After infection, bacteria invade the wall of the intestine which typically becomes inflamed, thickened, and loses the ability to transport nutrients efficiently.  MAP organisms are very hardy and can withstand freezing, high temperatures, and can persist for months or years in soil, water, or manure.

How can Johne’s disease affect my herd?

NAHMS (National Animal Health Monitoring System) studies found approximately 68% of U.S. Dairy herds and 8% of beef herds are infected.  The infection rate in other ruminants such as sheep, goats, and alpacas is not known.  The cost to producers ranges from $40 per cow in herds with a low Johne’s disease clinical cull rate up to $227 in herds with a high Johne’s disease cull rate.  Losses in beef cattle are due to decreased milk production resulting in lighter weaning weights, cow reproductive problems, and premature death.

In a herd of 100 lactating dairy cows, the diagnosis of one clinically infected animal implies that at least 25 other herd mates are infected.  Because young animals are the most susceptible to infection, Johne’s disease can spread rapidly within sheep and goat flocks.  Sheep and goats reproduce more often, and with greater numbers of offspring than cattle.   This results in more rapid spread of Johne’s within a sheep or goat herd compared to cattle.

How is Johne’s disease spread?

Herds are usually infected by the introduction of infected cattle.  Once in a herd, Johne’s disease usually spreads as young calves ingest manure from infected cows.  Calves can also be infected by drinking milk from infected cows or before birth while still in the womb.

What can I do to control Johne’s disease?

The USDA supported Voluntary Bovine Johne’s disease control program has been proven to decrease numbers of infected animals while increasing producers’ bottom line by increased production and reduced culling.  Testing along with management is also economical when taking into account the diseases devastating effect on production.  If nothing is done, the infection within herds will increase over time.  Testing allows producers to know the status of their herds.

Johne’s Certified Veterinarians have completed special training which allows them to develop Risk Assessment Management Plans for producers.  The RAMP is an individualized plan for management changes to reduce exposure to the organism, specific goals and steps to take to ensure management goals are followed, and a logical approach to monitoring and testing.

Together we can make a difference to improve the welfare of our livestock, increase production and profits for the individual producer and industry, while being proactive to protect our consumers.  Please contact your Johne’s disease coordinator to find a Johne’s Certified veterinarian to develop a program for you.

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More information on Johne’s Disease may be found in the following publications:

Beef:
Spring 2012
Fall 2011

Summer 2011
Fall 2010

Dairy:
Spring 2012
Fall 2011
Summer 2011

Fall 2010

 

HDOA CONTACTS:

Edith S. Terwey DVM
Johne’s Disease Coordinator
Livestock Disease Control
Hawai`i Department of Agriculture
99-941 Halawa Valley Street
Aiea, HI 96701
E-mail: Edith.S.Terwey@hawaii.gov
Phone: 808.483.7108

Kim N. Kozuma DVM
Deputy State Veterinarian
Livestock Disease Control
Hawai`i Department of Agriculture
75 Aupuni Street
Hilo, HI 96720
E-mail: Kim.N.Kozuma@hawaii.gov
Phone: 808.933.3307