Steroid-responsive generalised sterile necrotising pyogranulomatous lymphadenitis in a cat

A 1.5-year-old neutered male cat was presented with fever, inappetence, lethargy and marked generalised lymphadenopathy of 4 days duration. Excisional biopsy of peripheral lymph nodes revealed necrotising pyogranulomatous lymphadenitis. Extensive investigation failed to identify an underlying infectious [bacterial (Bartonella, Mycobacteria, Mycoplasma, other Gram-positive or -negative bacteria), viral (feline infectious peritonitis), protozoal (toxoplasmosis), or fungal], neoplastic or inflammatory condition. No improvement was observed with short-term antimicrobial therapy with amoxicillin-clavulanate. Treatment with an immunosuppressive dosage of prednisolone resulted in complete resolution of clinical signs. Seven months after prednisolone withdrawal, the cat remained in good general condition. This is the first description of a steroid-responsive necrotising pyogranulomatous lymphadenitis in a cat, and this entity might be considered in cases with generalised lymphadenopathy and fever.