Caseous lymphadenitis

The pseudo- tuberculosis ( caseous lymphadenitis, caseous lymphadenitis ) is a tuberculosis -like, infectious bacterial disease of sheep and goats caused by Corynebacterium pseudotuberculosis. It usually occurs sporadically in older animals and remains clinically usually without symptoms. The purulent caseous changes in the lymph nodes and internal organs are usually only detected at slaughter.

Pathogens and occurrence

The pathogen, Corynebacterium pseudotuberculosis is a Gram-positive, rod-shaped bacterium that was discovered in 1885 by Edmond Nocard. He is considered a facultative pathogen and is extremely resistant and thus capable of infection in the area long.

The pseudo- tuberculosis occurs worldwide and usually occurs as a single animal disease, also heaped under poor housing conditions. Most often older animals are affected.

Excretion is via pus from disrupted lymph nodes and in the faeces. Transmission is usually through wounds, such as can occur for example in the sheep-shearing, with pathogen- containing material (feces, soil ) are contaminated. Rare is also an infection through the navel ( omphalogen ), the bloodstream ( hematogenous ), the intestine ( enteric roe ) or via the airways (via air ) via the inhalation of dust containing pathogens.

Clinical picture

The disease is usually asymptomatic and is diagnosed only at slaughter. Only in the case of superficial lymph node involvement may lead to non-painful, visible swelling of the lymph nodes. At the opening of this lymph node, a yellow-green pus pours.

Rarely, it may occur tympanites by increasing the lymph nodes in compression of the trachea and thus to respiratory problems or infection of the Mesenteriallymphkoten. Very rarely, mastitis, uterine lining inflammation or central nervous pseudotuberculosis may occur. In the rarely occurring pseudotuberculosis of lambs navel inflammation, joint inflammation and abscesses can occur in the liver.

In the pathological section fall on purulent Lymphknotenabszesse that are filled with a cheesy to mortar-like mass. Typical is a concentric layering of these abscesses ( onion- like), which are surrounded by a thick capsule of connective tissue. In internal organs (lung, liver, spleen, kidney, udder, testicles) greenish cheesy foci may occur, which can also calcify.

Therapy

Since the disease is usually not clinically noticed no therapy is initiated. In fracturing superficial lymph nodes they can be surgically removed or antiseptic treatment.

Therefore, the main focus is on prevention, in particular the avoidance or antiseptic treatment of injuries, stable hygiene and disinfection measures (especially the intermediate disinfection of instruments for sheep shearing ). With increased occurrence in a herd can be a pathogen-specific vaccination can be performed.