Took the dog for a two hour run on Saturday. She was kinda limping that afternoon. Just took a little walk on Sunday and gave her some asprin before bed. This moring, she couldn't stand up. I carried her to vets right away and at the end of the visit, she is running around like a normal Brittany. Vet took blood for tests but didn't give any definite answer for what was wrong. If this has happened to you, I would appreciate some sage advice.