Corynebacterium pseudotuberculosis goat lymphadenitis and mastitis

Abstract

In a goat farm, 16 goats showed an increase in the superficial cervical, patellar and superficial inguinal lymph nodes, as well as nodular formations in the udder. After slaughter, these animals were diagnosed with caseous inflammation of the lymph nodes and nodular mastitis. In bacteriological examination, the bacterium Corynebacterium pseudotuberculosis was isolated from the foci of inflammation. The object of the study was 16 goats at the age of two to three years. Samples of organs of three goats (out of 16) served as material for histological and bacteriological research: samples of lymph nodes, lungs and mammary glands, fixed in 10% formalin solution. Histological sections were stained with hematoxylin and eosin. Lymph nodes and abscesses in the udder were used for bacteriological examination. On clinical examination, all 16 goats showed a strong increase in the superficial cervical, patellar and superficial inguinal lymph nodes. The lymph nodes were spherical, 4‐6 cm in diameter, dense, painless. The udder was enlarged and tuberous. During milking, curd particles were found in the milk. In general, the condition of the goats has not changed, the appetite has been preserved. Post‐mortem examination revealed changes in the lymph nodes, mammary gland and lungs. The tissue of the lymph nodes is mostly replaced by soft, cheesy contents of a gray‐white color, enclosed in a thick, dense capsule. The udder contains numerous encapsulated lesions with a diameter of 0.5 to 3.0 cm, containing a thick, white, homogeneous mass. Single dense yellow‐white lesions up to 1 cm in diameter were found in the lungs. In histological sections of the lymph nodes, eosinophilic detritus and dark purple, hematoxylin‐stained fragments of cell nuclei, as well as neutrophils and macrophages were found. In histological sections of the mammary gland, in the alveoli, numerous neutrophils, macrophages and fragments of destroyed cells were found. In the histological sections of the lungs, foci of inflammation with accumulations of leukocytes with a large proportion of macrophages were found, as well as necrotic detritus. Bacteriological examination isolated the bacterium Corynebacterium pseudotuberculosis. It is known that C. pseudotuberculosis, as the causative agent of caseous lymphadenitis, is dangerous both for animals of many species and for humans, causing granulomatous inflammation of the lymph nodes and other organs. Moreover, there have been cases of C. pseudotuberculosis infection in humans through the consumption of raw goat's milk and cheese. These circumstances make the diagnosis of caseous lymphadenitis an important measure in the care of goats, especially during lactation.