Background Reports of canine pyoderma gangrenosum (PG) are uncommon in the veterinary literature. Rarer still are cases describing dogs with both skin lesions and internal organ involvement. Objective To describe a case of canine PG with skin and internal organ involvement. Animals A client‐owned dog. Methods and materials Complete blood count, serum chemistry, C‐reactive protein and SNAP cPL tests, and abdominal ultrasonography and fine‐needle aspiration of the spleen were performed. Results The dog was treated with oral prednisolone and ciclosporin. After three months of therapy, ultrasonography revealed normalization of the spleen and resolution of skin lesions. Conclusion and clinical importance Dogs with skin lesions compatible with PG should be screened carefully for internal organ involvement. Ciclosporin may be a useful treatment for the immediate and long‐term management of canine PG.