Epidemiological and pathological aspects of salmonellosis in cattle in southern Brazil

Abstract

Salmonellosis is a bacterial disease that affects several domestic animal species, and is commonly diagnosed in cattle, horses, and pigs. This study aimed to describe the epidemiological and pathological findings of eleven cases of enteric salmonellosis and two cases of salmonellosis with pulmonary involvement in cattle in Rio Grande do Sul State, Brazil. Clinical signs included fever, yellow diarrhea, sometimes with blood streaks, and dyspnea, with a clinical course ranging from 1 to 30 days. Eight cases occurred as outbreaks, whereas five cases occurred individually. Risk factors included inadequate handling practices, such as overcrowded facilities and comorbidities, including anaplasmosis. The main gross finding of the enteric presentation was fibrinonecrotic enterocolitis, occasionally associated with button ulcers, mesenteric lymphadenomegaly, splenomegaly, cholecystitis and hepatomegaly. In addition, one steer with a chronic clinical progression presented severe segmental thickening of the ileum, associated with intestinal rupture and peritonitis. In the respiratory system, the main findings were reddened, non-collapsed lungs, with multifocal areas of atelectasis. The main microscopic findings were observed in the small and large intestines, and these were characterized by severe necrosis and mucosal ulceration, associated with marked inflammatory infiltrate of neutrophils and fibrin deposition intermixed by rod-shaped bacterial aggregates, and fibrosis, as well as interstitial pneumonia. Seven cases yielded positive bacterial cultures for Salmonella spp. and three serovars, namely Typhimurium, Dublin, and Panama were identified. All cases exhibited immunolabeling for Salmonella spp. using immunohistochemistry.

A Case Report of Hepatosplenomegaly Due to Chronic Salmonellosis in Holstein Calves

“…Hepatosplenomegaly may have been caused by the calves being in the chronic stage of the disease and the spread of infection by haematogenous route. Mild jaundice detected in only one calf is consistent with the literature data (Molossi et al, 2021;Casaux et al, 2023).…”

“…is a major cause of diarrhea, serovar and host-associated factors can lead to severe systemic consequences. Hyperemia in the heart and intestine, enlarged mesenteric lymph nodes, thickening of the intestinal wall and hepatosplenomegaly observed at necropsy are consistent with the literature data (de Aguiar et al, 2021;Molossi et al, 2021;Casaux et al, 2023). At necropsy, hepatosplenomegaly was remarkable in the calves.…”

“…observed in calves may partially benefit from antibiotic treatment (de Aguiar et al, 2021), but generally do not respond to antimicrobial agents due to resistant Salmonella spp. strains (Molossi et al, 2021). Especially in calves with septicemic, aggressive antibiotic treatment in the early period of infection and treatment according to the antibiogram result is recommended (Wray & Davies, 2000).…”

“…Infection can be seen in epidemic as a result of management mistakes and exposure of calves to stress (Hadimli et al, 2011). Although pathologists usually associate salmonellosis with enteric lesions such as diphtheritic membranes (Wray & Davies, 2000), highly variable necropsy findings have been identified in various literature data (de Aguiar et al, 2021;Molossi et al, 2021;Casaux et al, 2023).…”

Investigation on some bacterial and fungal causes of buffaloes calves diarrhea with emphasis on suitable treatment

“…Infected calf considered a source of infection either through direct contact or food borne routes where shedding the organism for variable periods of time and intermittently depending on the degree of infection. Diarrhea due to salmonella infection is watery and mucoid with the presence of blood and fibrin calves can shed salmonella for variable periods of time and intermittently depending on the degree of infection (Molossi et al 2021).…”