We were at the dog park yesterday. Bento was playing around with a 5 month german shepherd when another dog can running in to join the fun. This action caused Bento to start a game of "chase me!"
Unfortunately for Bento, this other dog (an akita mix?) was much more coordinated and powerful than the puppy. The other dog ran after Bento, caught up with him, and knocked Bento over--possibly stepping on him in the process. Bento let out a loud yelp and tumbled over and over and over. When he stopped rolling, he got up and limped over to us. We left after that.
Bento's been limping since. When he gets up from sitting or lying down for a period of time, he doesn't put any weight on his back left paw. After a while, he puts some weight on it, and there's a noticeable limp.
We've gently checked his paw pad, paw, ankle, knee, and hip, but there's no one spot that seems to bother him. But he still limps.
I'm so sorry Bento. Mommy failed you.