my cat is 12 years old and about a year ago i noticed her hair was clumping and recently she started drooling and blood was also visible in her saliva, and noticed a tooth was missing, she has also been acting very different, shes an indoor cat but now when the door is open she goes out for a little while and comes back(its weird because she has never been outside before beside laying right outside the door) it seems like shes out of it because she has a dogs mind all of the sudden, when ever she sees food she like stalks you or runs into the kitchen( i dont know if shes getting all this from my neighbors dog, because their dog is constantly i my house) i dont know what is wrong with her the worst part of all is that her breath is horriffic and anywhere she drools it clings to, please Help!! i dont know what is wrong