My dog (3 years old) has been acting very depressed and not her normal self. She used to wag her tail and lick us, and also was very excited when we came home, or if we were going on a walk. We got a new puppy about 3 weeks ago. They got on really well at first, and my older dog liked to play with the puppy and wrestle about. But now she is acting withdrawn. She is only eating small amounts and not playing at all. She does not come to greet us or visitors at the house, and does not wag her tail at all, keeping it tucked under her. She is sleeping lots and now wont play with the puppy. She is also running away from me when i get her lead out, and does not want to go for a walk. If I make her go, she will drag behind on the lead and keep looking back to the house. I don't know if she is getting sick, or if she is depressed. I am so worried about her. I will take her to the vet if I think she is sick, but she does not have any symptoms apart from this depression. I have had bad experiences with the vet a few times before, when I have ended up paying a lot of money for unnecessary tests and medicines that did not work (for my cat and chickens). So I don't want to go down that road again. Thank you for any advise.