DAIRY: GALLERY 1 -JOHNE'S INFORMATION CENTER

Use this section of the
site for a Johne's disease
visual reference.

	Diagnosis heifer #11 Results of an experimental infection study in calves. Pattern of diagnostic test results for heifer #11.

	Diagnosis heifer #13 Results of an experimental infection study in calves. Pattern of diagnostic test results for heifer #13.

	Experimentally infected heifer #13 and calf August 1995 heifer #13, infected with M. paratuberculosis as a one month-old calf, had her own first calf. She developed clinical Johne’s disease within a week of calving.

	Enlarged mesenteric lymph nodes Johne’s disease frequently causes lymph nodes near the intestine to become enlarged (arrow).

	Thick, corrugated ileum mucosa of Heifer #13 The classical pathology of Johne’s disease in cattle, visible to the naked eye, is a thickened ileum. The extensively folded inner, mucosal, surface looks like corrugated cardboard

	Acid_fast stain: ileum Special stains, called acid-fast stains, can reveal the red, rod-shaped mycobacteria in the intestinal tissue. They are clustered inside white blood cells.

	AGID blood test for Johne’s disease AGID test, sold under the trade name Rapid Johne’s Test, is a simple, easy to perform test for Johne’s disease that can be used on cattle with clinical signs; diarrhea and weight loss.

	Lymphangitis in a bovine ileum Outside surface of a bovine ileum infected with M. paratuberculosis. The white line (arrow) indicates inflamed and dilated lymphatics: pathology indicative of Johne’s disease in cattle.

	Diarrhea: an early sign of Johne's disease in cattle Many factors affect the consistency of cattle manure, however, loose manure to watery diarrhea are clinical signs consistent with Johne’s disease.

	Scanning electron micrograph of M. paratuberculosis M. paratuberculosis magnified over 50,000 times as seen by an electron microscope.

	Guernsey cow with clinical signs of Johne's disease Chronic diarrhea and rapid weight loss are the classical signs of Johne’s disease in cattle. Johne’s disease is NOT seen more often in Guernseys as compared to other dairy cattle breeds.

	Giant cell in ileum Giant cells in a acid-fast stained tissue section. Seeing such cells, along with acid-fast bacteria is diagnostic for paratuberculosis.

	Holstein cow with clinical signs of Johne's disease Clinical signs of Johne’s disease include: diarrhea, rapid weight loss, good appetite.

	Histopathology: ileum A thin section of bovine intestine stained with H&E, among the most common stains. The normal architecture of the tissue is changed due to inflammation in response to the M. paratuberculosis infection.

	Standard culture method Herrold’s egg yolk agar is a culture medium widely used to grow M. paratuberculosis from clinical samples like feces. Growth of bacterial colonies on this medium containing mycobactin, and not on medium without mycobactin (right hand tube), is indicative of M. paratuberculosis.

	Bottle jaw can be a sign of Johne's disease Due to low levels of serum albumin caused by Johne’s disease some cattle develop this lump under the jaw called "bottle jaw".

	Spread and control of Johne’s disease in a dairy herd A computer simulation model was created to help understand the dynamics of spread of M. paratuberculosis infections in dairy herds and what methods will results in fastest control. This graph shows typical results from such a simulation model.

	Heinrich Albert Johne In 1895, this German physician, and his American colleague, Frothingham, were the first to describe the disease now known as bovine paratuberculosis.

	Thickened intestinal mucosa due to Johne's disease In cattle, infection of the intestine with M. paratuberculosis leads, over the course of several years, to marked thickening. This photos shows a normal (bottom) and affected bovine ileum.

	Colonies of M. paratuberculosis The colonial morphology of M. paratuberculosis is affected by the composition of the culture medium. This close up view of M. paratuberculosis colonies on Middlebrook agar medium shows the very rough colonial morphology typical of the organism grown in the absence of Tween.

	Johne's vaccine injection site The Johne’s disease vaccine when used in the U.S. is administered to calves less than 30 days-old. It often causes a large lump at the injection site. This Wisconsin cow has a Johne’s vaccine-induced granuloma in her brisket.