I hope Buddy is okay!

When Mickey was a pup, my brother accidentally fell on him (he was running in the hall and Mickey came up behind him and surprised him). He cried and couldn't walk without wobbling or limping. So my mom lay him down on the floor and massaged his legs. The more she did it, the more it helped.

I hope the aspirin helps but maybe you can try massaging his legs too. It might relieve some tension.

Good luck.