Multifocal Cervical Instability and Cervical Spinal Cord Impingement in a Masai Giraffe (Giraffa camelopardalis tippelskirchi)
A female, hand-reared, Masai giraffe calf (Giraffa camelopardalis tippelskirchi) presented with an acute onset of localized swelling on the mid-lateral neck region at 18 weeks of age. The lesion progressed to a mild kink or lateral deviation of the neck and within one week was associated with incoordination, weakness, head-resting behavior, and occasional regurgitation. Radiographs showed complete destruction and collapse of the joint between cervical vertebrae 4 and 5 (C4, C5) with shortening, lysis, and proliferative remodeling of the adjacent vertebral bodies. Differential diagnoses considered included trauma (fracture, subluxation), osteomyelitis (discospondylitis), and neoplasia. Treatment consisted of stabilization of the neck by an external splint (Orthoplast™, AliMed®, Dedham, MA; 15 weeks), and systemic antibiotics (15 weeks). Upon removal of the splint, radiographs showed osseous bridging and callus formation. The giraffe developed a permanent bend, decreased range of motion, and decreased flexibility in the neck associated with the eventual fusion of C4 and C5. No other obvious clinical, developmental, or neurologic problems were noted.
The giraffe was transferred to another zoo at 1.5 years of age. At about three years of age, the giraffe began showing clinical signs of intermittent regurgitation, decreased activity, abnormal gait, frequent resting of the head and neck, a low neck posture, and progression of the bend in the neck. Radiographs revealed hyperflexion at C2–C3, fusion of C4–C5, lateral displacement and hyperflexion of C5–C6 with extensive bone proliferation ventrally and narrowing of the vertebral canal, and hyperextension and malalignment at C6–C7 with bone proliferation. Within two weeks of the radiographs, the giraffe became laterally recumbent and unable to rise due to paraparesis and ataxia. The giraffe was humanely euthanatized. Postmortem dissection and computed tomography of the cervical spine confirmed the antemortem diagnoses.
The assistance, photographs, and care provided by the Toledo Zoological Gardens, Louisville Zoological Garden, and their staff are gratefully acknowledged.