A neurological locomotor disorder in sheep grazing Stachys arvensis

Objective To describe the clinical signs and pathology of a neurological lo comotor disorder in sheep associated with ingestion of Stachys arvensis. Design Field observations and laboratory examinations. Procedure Clinical and pathological examinations were performed on sheep wi th suspected S arvensis intoxication. Field observations Merino sheep in a flock on the southwestern slopes of Ne w South Wales developed a neurological disorder after grazing S arvensis. A ffected animals had pelvic limb paresis and a proprioceptive deficit. When forced to exercise they stumbled and collapsed. Recovery following removal from the plant was slow. Many deaths were associated with the outbreak. Results Affected sheep developed a mild degenerative myelopathy and periphe ral neuropathy. Deficiencies of vitamins A and E were also observed in the affected flock. Conclusion Grazing S arvensis is sometimes associated with a neurological l ocomotor disorder in sheep.