This morning I heard one of my dog's yelp. I went to check on her and she didn't jump on me like she normally does. I also noticed her tail was limp. It would hang low but it would still wag, just not as much. I checked for bite marks, swelling, or any other abnormalities (none) and for snakes (none). She's still eating a little (which isn't unusual b/c of the heat) but she seems a little down. Has anyone seen this before?