When I straighten my dogs front paw she cries out in pain and tries to keep me from touching her paw again. However when I was feeling her bones she had no reaction and I felt no difference when compared to the other paw. Sometimes she limps and other times she’s fine, even has the energy to chase after me and play. I’m really worried because she’s a small 2 year old 4 lb. Yorkshire Terrier and when she cries out in pain it sounds like she’s screaming.

today she was running through bush chasing squirrels
when we called her she came running towards us “lop-sided”; looked as if hind left leg wasn’t working
it was not any kind of limp I’ve seen before; the leg didn’t look being favored but looked not working, not providing the right support properly
Cookie sat down while we were going to try to see what’s going on
meanwhile she heard another squirrel and dashed off back into the bush again
looked like the leg wasn’t quite right but she didn’t seem to care
we then fetched and leashed her and after short time everything seemed fine until the time of this writing 4:19PM
often problems resurface after some rest so I’m concerned what she’s going to look like after longer rest; so far she seems perfectly normal again, though

Seeing a vet tomorrow but hoping for some comforting thoughts on what the heck it could have been … ?

Toby is a 3.5 month old tabby.
It’s not too bright in my apartment.
He’s eating well, pooping well, chasing around after things — seems to be in very good energy.