Case Report Streptococcus constellatus-associated pyoderma in a dog

This report describes a case of chronic and deep pyodermitis in a 4-year-old male dog with a 3-month skin problems history that had been treated unsuccessfully with fluoroquinolone therapy, prescribed by a private medical veterinary practice, without an early diagnosis. Microbiological examination and antimicrobial susceptibility testing were performed in our laboratory (Faculty of Veterinary Medicine) and a diagnosis of Streptococcus constellatusassociated pyoderma in the dog was made. A new antimicrobial treatment, with tetracyclines, was designed after the definitive diagnosis and antimicrobial susceptibility testing performed by the Kirby–Bauer disc diffusion method. The dog remained free of clinical illness at completion of therapy. To our knowledge, this is the first case of a canine pyoderma caused by S. constellatus, a commensal organism which may also cause pyogenic infections. Furthermore, this study confirms that a fluoroquinolone represents a poor empirical choice for initial therapy of canine pyoderma.