Sporotrichosis in dogs: epidemiological and clinical-therapeutic profile and the emergence of itraconazole-resistant isolates.

Sporotrichosis is a neglected and emerging mycosis caused by the traumatic implantation of Sporothrix propagules into the (sub)cutaneous tissues of humans and animals. We evaluated canine sporotrichosis's clinical-therapeutic, epidemiological profile and in vitro susceptibility of isolates to itraconazole. The variables were evaluated by a chi-square test. Sixty-nine dogs were infected with Sporothrix spp., and the molecular identification revealed an overwhelming occurrence of S. brasiliensis as the etiological agent. The epidemiological profile was male (56.5%), adults (4.9 ± 1.92 years old; 69.6%), and mongrels (53.6%). The clinical signs were 76.8%, ulcers, draining tracts, and nodules were predominant, mainly in the nasal region (82.2%). Dogs were diagnosed late with an evolution time of up to three months (34.8%). According to the prior therapeutic information, 52.2% received empirical therapy, 79.2% antibiotics, and had a 0.29 significantly greater chance of presenting lesion evolution time greater than three months (p < 0.05; OR 1/0.29). Additionally, 25 Sporothrix brasiliensis isolates recovered between 2006-2012 (n = 15; MIC: 0.06-2 μg/ml) and 2013-2018 (n = 10; MIC: 2→16 μg/ml) were tested against itraconazole. These findings highlighted the resistance to itraconazole in clinical cases due to Sporothrix brasiliensis occurring after 2013, showing the temporal evolution of itraconazole resistance. We warn of the importance of accurate and early diagnosis in Sporothrix-affected areas, and we report the emergence of itraconazole-resistant isolates in Southern Brazil.