The Plague Dogs (1982)

Synopsis
Like Watership Down, Plague Dogs is an animated cartoon feature based on a novel by Richard Adams and produced by Martin Rosen. And also like Watership Down, it is more appropriate for an older audience. Two dogs escape from a British government research lab. As the authorities hunt down the canine fugitives, the two dogs search for their original master and for a place where they'll be free from the iniquities and cruelties of Mankind. Plague Dogs was completed in 1982, but was not released in the US until two years later. ~ Hal Erickson, All Movie Guide