Figure 14-102.

Meningeal Fibrosis, Leptomeninges (Pia-Arachnoid Mater), Dog.

In old dogs the leptomeninges can have areas of fibrosis (white areas around blood vessels in sulci), particularly in the sulci. This lesion must not be confused with acute leptomeningitis and accumulation of exudate in the leptomeninges and subarachnoid space. In the latter the exudate extends into the sulci and also covers the gyri (see Fig. 14-43, A).

(Courtesy College of Veterinary Medicine, University of Illinois.)