Aim. To determine the cause and nature of a disease in newborn New Zealand
Romney lambs characterised by progressive weakness and premature death.
Methods. Affected lambs were examined clinically, humanely killed and submi
tted to necropsy. Selected formalin-fixed tissues were examined histologica
lly. Data on the parentage of the lambs were collected.
Results. The principle lesions found were degeneration and loss of neurons
in ventral horns of the spinal cord and brain stem and Wallerian degenerati
on of motor nerves and denervation atrophy of skeletal muscles fibres.
Conclusion. The lesions are those of a lower motor neuron disease which app
eared to have a genetic cause.