Serial MRI to monitor the progression of a case of sphenoid bone osteomyelitis in a dog (Canis familiaris)

A 2‐year‐5‐month‐old, male, neutered, crossbreed dog presented with third eyelid protrusion, right eye exophthalmos and facial hyperaesthesia. Neurological examination was suggestive of a lesion affecting the right optic nerve. Magnetic resonance imaging allowed a presumptive diagnosis of sphenoid bone osteomyelitis, meningitis and right‐sided optic neuritis. The dog was discharged with clindamycin (13 mg/kg/8 h), amoxicillin–clavulanate (25 mg/kg/8 h), gabapentin (10 mg/kg/8 h), paracetamol (15 mg/kg/8 h) and prednisolone (0.5 mg/kg/24 h). Paracetamol, gabapentin and prednisolone were gradually stopped. A 3‐month follow‐up revealed right‐eye blindness. Magnetic resonance imaging showed improvement in changes compatible with osteomyelitis and meningitis resolution, prompting clindamycin cessation. At the 6‐month follow‐up, magnetic resonance imaging indicated only right optic nerve atrophy. Amoxicillin–clavulanate was stopped. There had been no relapses at 12‐month follow‐up. Serial magnetic resonance imaging studies were pivotal in adjusting antibiotic therapy, and instilled confidence for treatment cessation upon lesion resolution. This marked the first use of serial magnetic resonance imaging to modulate sphenoid bone osteomyelitis treatment in dogs.