Hereditary neuraxial oedema in a Poll Hereford herd.

Cases of neuraxial oedema in a Poll Hereford herd were investigated and the pedigrees of affected calves determined. In all cases, and over no more than 3 generations, the pedigree led back to a common bull. Analysis of the herd breeding records supported an autosomal recessive mode of inheritance of the disease. Fractures of the femoral heads, acetabular cartilage and/ or bone, or both, were seen in some affected calves. This lesion was probably induced during birth or soon after, and the suggestion is made that such hip lesions could be regarded as highly suggestive of hereditary neuraxial oedmea of Herefords. The majority of calves showed clinical signs at birth, but 2 calves did not develop clinical signs until they were 2 days old.