Acute Leptospirosis Outbreak in Cattle: A Case Report.

Leptospirosis is a globally distributed re-emerging zoonotic disease caused by Leptospira species. In cattle, the clinical course varies from a subclinical-chronic infection, commonly found in adult animals, to a severe acute syndrome mostly found in calves. The present study reports an outbreak of acute leptospirosis, following favourable climacteric conditions. Seven affected farms were monitored. Clinical observations from infected animals (n = 30) revealed two distinct patterns: lactating calves experienced hyperacute courses, often culminating in death, and older animals, mainly steers, displayed signs of apathy, anorexia, icterus and haemoglobinuria. Necropsies confirmed jaundice and haemoglobinuria, aligning with a presumptive diagnosis of leptospirosis. Haematology and serology results further supported this diagnosis. Pomona and Mozdok serovars were the most prevalent (62.5%) and had the highest mean agglutination titres, 1:1160 and 1:700, respectively. Antimicrobial treatment of sick animals consisted of oxytetracycline. Chemical metaphylaxis and prophylactic measures were established to control the outbreak in cohabiting animals. Environmental factors like climate change are expected to contribute to more frequent leptospirosis outbreaks. Comprehensive serological surveys are recommended to develop region-specific control measures, emphasising the importance of vaccination as a practical and effective prophylactic measure.