Almost two year old pug suddenly peeing as if marking territory everywhere in house. Started in the bedroom where the kitty cat resides. Started just in that bedroom when he could get in. now it is more frequent and on the couch or curtains, or on the floor outside bedroom door. It is just a lift of his leg and a little squirt squirt. He is not fixed... never been studded... is he marking his territory? Or do we need to see a vet.

Did you just recently get the cat? Also, is the cat spayed or neutered? These can all cause your dog to mark his territory

I would call the vet and also consider neutering. He may have a urinary infection but it sounds more like marking. My personal preferrence is all pet dogs should be neutered or spayed

If there is ANY change in an animal's behavior, yes, the animal needs to see a Vet.