User blog comment:Wiryawan310/Error: Deformed Animals in The Sims 3/@comment-4072597-20111125204527/@comment-98.155.29.185-20111126013002

Sounds like your graphics card can't handle the rendering, so it's simplifying your pets by removing the details like fur. This happens to me when switching between very large, high detail lots (lots of objects) but everything will load after a second and look normal.