I have a 2 year old Jack Russell Terrier. She did not act like herself yesterday. She refused to walk or eat and has been sleeping for long periods throughout the day. She's also been restless, wandering around too much in search of a comfortable sleeping position and sticking her tongue out continuously. She's also been pooping out diarrhea. I also noticed she was shaking in her sleep today, which she had never done before. I'm not sure whether I should take her to the vet or wait and see if she improves.