Delayed swayback in goat kids, a study of 23 cases.

Abstract

The results of a retrospective study of 23 goat kids with delayed swayback are reported. Principal clinical signs were ataxia, loss of postural control, spasticity of the hindlimbs, and muscular weakness, often progressing to permanent recumbency. Denervation of skeletal muscles was demonstrated by electromyography in 2 kids. Three kids slowly recovered during hospitalisation. Histopathological changes were characterized by degeneration of selected neuronal populations with their processes within the central and the peripheral nervous system. Affected systems included upper motor neuron, vestibular, general proprioceptive, and lower motor neuron pathways, with additional involvement of the cerebellar cortex in some animals. Our findings, including limited ultrastructural observations, support the notion that the neuraxon rather than the myelin sheath is the prime target of disease in delayed swayback. The available copper values of affected kids and their unaffected herd mates were significantly lower than those of random control goats, which provides further support for a role of copper deficiency in the aetiology of this disease in the goat.