Primary phenotypic features associated with caudal neck pathology in warmblood horses.

Background: Detailed descriptions of clinical signs associated with radiological findings of the caudal cervical vertebral column are not available.

Objectives/hypotheses: Describe the clinical features associated with neck pain or stiffness, neck-related thoracic limb lameness, proprioceptive ataxia consistent with a cervicothoracic spinal cord or nerve lesion, and their frequency of occurrence compared with control horses.

Animals: A total of 223 Warmblood horses.

Methods: Case-control study. Controls and cases were recruited prospectively. All horses underwent predetermined lameness and neurologic examinations. The frequency of occurrence of each clinical feature was compared between cases and controls and relative risk (RR) were calculated.

Results: Ninety-six cases and 127 controls were included. Forty-seven (49%) of the cases were classified as neurologic, 31 (32.3%) had thoracic limb lameness, and 18 (18.7%) had neck stiffness or pain or both. Focal caudal cervical muscle atrophy (46, 47.9%), hypoesthesia (38, 39.6%), patchy sweating (16, 16.7%), hyperesthesia (11, 11.5%), and pain upon firm pressure applied over the caudal cervical articular process joints and transverse processes (58, 60.4%) were only observed in cases (P < .001). Sideways flexion of the neck was restricted in a higher proportion of cases (47/96, 49%) compared with controls (40/127, 31.8%; P = .009, RR 1.5). Hopping-type thoracic limb lameness was only observed in cases, (30, 31.6%). Deterioration in lameness after diagnostic anesthesia occurred in 13/31 (41.9%) cases.

Conclusions And Clinical Importance: Systematic clinical evaluation using the methods described should enable clinical differentiation between horses with caudal cervical lesions and horses with other causes of gait abnormalities.