Chihuahuas, rat terriers and miniature poodles are muscling in on strength contests long dominated by big dogs. It takes high-protein diets, sharp nails and cinder blocks.

The 173 pound Golden Retriever was almost put down and then he met his new mom. Kai weighed a whopping 173 pounds when Pam Heggie started fostering him -- more than 100 pounds overweight for an adult ...