I have 3 huge great danes and they cost me around $70 dollars a moth for feeding hardly a set back.
Also I wanted to say shabbos is not as big as problem with pets as people say Rav Wosner paskened to my father that since the animal wants to be petted it is not a problem of muktza, and walking them is only a problem of carrying if thers no eiruv and the lead is not taut.