Feline botulism: two decades and two reports

Abstract

This study describes an outbreak of type C botulism in domestic cats in central region of Brazil, two decades after the only previously reported natural case in the specie. Between August and October 2024, 21 cats presented with flaccid tetraparesis and were clinically evaluated. The course of the clinical signs varied from acute to subacute, with signs including hypotonia of all limbs, bladder and intestines, hypophonia, and flaccid paralysis of masticatory muscles. Eight cats died due to cardiorespiratory arrest. Necropsy and histopathological analyses revealed no significant macroscopic or microscopic lesions. Botulinum toxin type C was detected in five cats through standard mouse bioassay: in feces (n = 3), liver (n = 1), and intestinal contents (n = 1). Although the toxin was not found in the remaining animals, botulism was not excluded based on clinical and epidemiological findings, absence of spinal or other neurological lesions, and the exclusion of other infectious agents. All cats tested negative for FeLV, Coronavirus, Toxoplasma gondii, and Neospora caninum, and were also screened for intestinal parasites. Despite the strong epidemiological evidence, including common exposure to commercial diets, hunting behavior, and outdoor access, the source of intoxication was not identified. This study highlights a rare and severe outbreak of feline botulism and reinforces the importance of considering this diagnosis in similar clinical scenarios.