Use PubMed to search for veterinary medicine by adding veterinary[sb] to your search! For example:prion AND veterinary[sb]
You can also navigate to Special Queries (from the left, blue side-bar). Select Veterinary Medicine/Animal Health and click veterinary search (link from explanatory text at top of page). Then, use your search History to combine the veterinary subset of PubMed to your other search terms (e.g. #1 AND #2).
Veterinary[sb] is a comprehensive search strategy of subject terms, title words and veterinary and animal health journal titles.It includes 171 core veterinary journals and currently retrieves over 1.4 million PubMed citations. Its oldest citation is from 1867!
For more information on the Veterinary/Animal Health special query, go to http://www.nlm.nih.gov/pubs/techbull/mj07/mj07_vet.html
With thanks to librarian, Barbara L for this blog post.