A 3‐month‐old male, entire, English bull terrier was presented for investigation of a 24‐hour history of lethargy, pyrexia and neck pain. Inflammatory cerebrospinal and synovial fluid analyses with identification of Pasteurella multocida in the left stifle were supportive of a steroid‐responsive meningitis‐arteritis (SRMA) and immune‐mediated arthritis secondary to septic arthritis in the left stifle. The patient was successfully treated with amoxicillin/clavulanic acid and immunosuppressive doses of corticosteroids. Follow‐up sampling of cerebrospinal and synovial fluids revealed resolution of the septic arthritis and SRMA after 6 weeks of treatment. Medications were tapered and discontinued after 16 weeks of treatment without any signs of relapse. Follow‐up was 16 weeks. This is the first case report of SRMA with the identification of P. multocida septic arthritis as the suspected trigger.