EXPERIMENTAL CEREBROSPINAL ELAPHOSTRONGYLOSIS (ELAPHOSTRONGYLUS-RANGIFERI) IN SHEEP

Seven lambs were inoculated with 150-3,000 infective larvae of Elaphostrongylus rangiferi and subsequently killed for autopsy. From one week post inoculation (p. i.), a marked eosinophilia was found, and one of the lambs showed signs of coughing, increased respiratory frequency and elevated body temperature. Pruritus was observed in three lambs during the period 5 - 10 weeks p. i. Gross and microscopic lesions were found in the liver, lungs, myocardium, kidneys, spinal nerve roots and in the central nervous system (CNS). The lesions resembled those previously reported in experimentally infected goat kids. The migratory route of the infective larve seemed to be haematogenous. Developing nematodes were sectioned in the CNS of a lamb killed at day 30 p. i. The nematodes found in the brain of this lamb were significantly thicker than those observed in the spinal cord. Intact nematodes were not detected in the remaining lambs which were all killed 149-151 days p.i. None of the experimental lambs shed E. rangiferi first-stage larvae in the faeces. These findings indicate that E. rangiferi gradually dies out in sheep and will not complete its life cycle in this animal species.