Maybe call the vet and see what they say.... Maybe they can cut you a deal or something it's woth a try... Better to be safe then sorry, i'm sure most vets understand about money and all that... When my kirby was sick we couldn't pay right away so we just paid bit by bit... You already have a dog with medical problems so at least they would know your good for the money and wouldn't take off... Who knows maybe the vet will say the cat will heal on his own... Does he have his shots??