Only a few states allow service cats such as Maryland Alaska Montana and Oregon 
But there lies the problem many cats can work as service animals just as well as a small dogs in fact they can even be better for some people like 
people scared of dogs people that have allergies to dogs or just a cat suits them better and several other reasons too please keep in mind that those reasons do not apply to everyone 
Cats are viewed as skittish and mean most of the time but there are many cats who are just as sweet as dogs 
Cats live longer than dogs on average so them being service animals would probably even be better than dogs and miniature pony’s as they wouldn’t have to retire as early
It would mean a lot to a lot of people if you would sign a petition for cats to be service animals in all states of the USA