Enteritis in sheep, goats and pigs due to Yersinia pseudotuberculosis infection

Abstract

The features of naturally occurring Yersinia pseudotuberculosis serotype III infections in 16 sheep, one goat and 3 pigs, and Y. pseudotuberculosis serotype I infections in 3 goats, are described. Affected animals usually had diarrhoea and were in poor condition or emaciated. A number were moribund or dead when submitted for necropsy. Thickening of the caecal and colonic mucosa was the only gross lesion attributable to Y. pseudotuberculosis infection, with liver or other visceral abscesses not being seen. Characteristic microabscesses were demonstrated in the intestinal mucosa of 10 sheep, one goat and one pig infected with Y. pseudotuberculosis serotype III and one goat infected with Y. pseudotuberculosis serotype I. Sheep, goats and pigs dosed orally with Y. pseudotuberculosis serotype III, the serotype isolated most commonly from these species, developed intestinal infection. In sheep and pigs, infection was accompanied by diarrhoea. Haematological changes and specific antibodies were elicited in all 3 species in response to infection. Microabscesses were seen in the intestinal mucosa of all experimentally exposed animals. The occurrence of field cases and the results of experimental exposure confirm that Y. pseudotuberculosis serotype III is an enteropathogen of sheep, goats and pigs. The association of Y. pseudotuberculosis serotype I with lesions in a goat, indicates that this bacterium may also be a pathogen of this species. It is concluded that Y. pseudotuberculosis serotype III is an enteric pathogen of a wide range of ungulate species including cattle, buffalo, deer, antelopes, sheep, goats and pigs. Serotypes I and II, while having a more restricted host range, are probably also pathogens of ungulates and, in particular, deer, antelopes and goats.

Caprine Enteritis Associated with Yersinia pseudotuberculosis Infection

“…The intestinal lesions consisted of multiple microabscesses and intestinal glandular hyperplasia. The lesional distribution resembled the previously reported finding [15] that infection by this organism in sheep and goats rarely produced characteristic microabscesses in the visceral organs. Yersiniosis takes a variety of clinicopathological forms: fulminant, subacute and chronic.…”

“…Although the exact origin of the present infection remains unknown, there might have been indirect contacts between the goats and cows in the dairy-producing area via feral birds or other animals. Alternatively, reservoirs maintaining infection might have been present in the caprine herd, as pointed out previously [13,15]. Further investigations on the origin of the infection should be performed for the purpose of prophylaxis of the disease.…”

“…Cattle and pigs are thought to be reser- voirs, particularly of Y. pseudotuberculosis serotype III [14,19]. No animals in the farm had immediate contact with cows or pigs.…”

“…The organisms are divided into the serotypes I to VI based on the somatic O antigenic structure, and serotype III has been found to be associated with the disease in a wide range of ungulate species, such as sheep, goats, pigs [13,15,16] and less frequently cattle [4,14]. Stress factors are generally thought to be necessary to precipitate the disease.…”

“…Y. pseudotuberculosis, a gram-negative and aerobic or facultatively anaerobic coccobacillus, is an infrequently incriminated pathogen responsible for enteritis and septicemia in various species of mammals and birds with seasonal prevalence in the cooler months [12]. The lesions are characterized by microabscesses with bacterial colonies in the intestine and mesenteric lymph nodes, and often in visceral organs [1,13,15,18]. The organism is also associated with mastitis [5,9] and abortion [10,21].…”