This list of animal anatomy resources includes skeletons and musculature of horses, dogs, cats, and birds.
Dog Anatomy
An informative site with illustrations, which also discusses variation between breeds and the factors that influence a dog's anatomy.
Cat Anatomy
Basic cat anatomy, with a link to musculature and a claw function, as well as a breed index and search function for further information on specific varieties.
Bird Skeleton
Extensive introduction to the bird skeleton, with a basic overview followed by detailed, labelled diagrams of main body parts.