Microphthalmia in Texel lambs.

AIM: To describe an outbreak of congenital microphthalmia in Texel lambs in New Zealand.

METHODS

Affected eyes were fixed in 10% formol saline, processed routinely for histopathology and stained with haematoxylin and eosin, Holme's silver and haematoxylin with and without luxol fast blue, and luxol fast blue alone.

RESULTS

Macroscopically, the globes and optic nerves were hypoplastic. Histologically, all embryonic components of the eye were present, but the lens, ciliary body, iris and retina were dysplastic. Axons of the hypoplastic optic nerve were poorly myelinated.

CONCLUSIONS

Congenital microphthalmia occurs in Texel sheep in New Zealand, and is likely inherited as an autosomal recessive trait.