Dandy-Walker malformation in two calves.

Two calves with unusual malformations of the skull and brain are described. Both calves showed doming of the posterior skull due to enlargement of the posterior fossa and cyst-like dilatation of the fourth ventricle. The cystic dilatation of the fourth ventricle formed a meningocoele in one calf. Aplasia of the cerebellar vermis was present in both calves. One calf showed agenesis of the corpus callosum. These features are consistent with the Dandy-Walker malformation of man.