– Dr. Michelle Arnold, Ruminant Extension Veterinarian, University of Kentucky
Figure 1: Recently calved cow with signs of Johne’s disease; dull hair coat, profuse watery diarrhea, and weight loss. Photo from “Management and Control of Johne’s Disease in Beef Sucker Herds” by Drs.Isabelle Truyers and Amy Jennings. In Practice July/August 2016/Volume 38, page 348.
What is Johne’s Disease?
Johne’s (pronounced Yo-knees) Disease is a slow, progressive disease of profuse, watery diarrhea and weight loss or “wasting” in adult cattle (Figure 1) caused by the bacterium Mycobacterium avium subsp. paratuberculosis, also known as “MAP”. This disease begins when calves (not adult cattle) are infected with MAP-contaminated colostrum, milk, feed, or water, most often around the time of birth. Once MAP enters a calf, the organism lives permanently within the cells of the large intestine where it multiplies and causes the intestinal lining to slowly thicken. Over years of time, the thickened intestine loses the ability to absorb nutrients, resulting in watery diarrhea and weight loss despite continuing to eat well. There is no blood or mucus in the feces, no straining, and no fever. These symptoms do not show up in adult cattle until 2-5 years of age or even older. There is no treatment available, and the animal eventually dies due to starvation and dehydration.
Why should a commercial beef producer care if they have Johne’s Disease in the herd?
Economically, Johne’s disease can be costly in a beef operation. It is believed that Continue reading Expanding your Herd? Frequently Asked Questions about Johne’s Disease and How to Keep it Off the Farm →