Hi, My dog, Star, loves to run at the dog park, pretty much nonstop, for a few hours. She does drink a lot of water while we're there and everything is fine. About 30-60mins after we get home, she then begins gagging and then throwing up what looks mostly like saliva and water. Is there any way to stop this from happening? Does this mean she's running too hard at the park? Too long? Again, she's fine the whole time we're at the park, it doesn't happen until she settles down in her bed. Any input is appreciated.