Is my kitty in heat?

I posted previously about my boyfriend and I finding a white kitty, not sure of the age. But she did not get along with my puppy AT ALL. Well the beginning of this week they started sniffing each other more, my puppy has finally gotten used to the idea that she isn't going anywhere. Well, the cat would still hiss and growl a bit up until tonight. She was hissing slightly last night but not too bad. But tonight... shes like being completely submissive to my puppy. She will walk up to the kitty and the cat will just roll over and let the puppy lick her ears! . I'm sightly on the weirded side. Anyway, down to the real question. The past three days the cat has been standing at the door meowing like crazy just wanting to go outside. Well, tonight shes worse and everytime you touch her she just rolls over and if you pet her butt, she will lie on the ground and stick her butt WAY up in the air. She wasn't doing this about three days ago. And this thing with the puppy, shes completely letting the dog lick her. I have a girl dog, so i have had to deal with her going into heat, and this just kind of seemed a bit like what Dutchess, my dog, went through. Now, we don't know much about the cat since she was lost, and we havent had the money to take her to the vet yet, so we dont know if she is a he or a she. Also, we dont know if she has been fixed. So, I don't know if she could even be in heat. Does anyone know what could be going on? Thanks so much.

It does sound like she is in heat.You should be able to tell if indeed your cat is a female by looking! Either way your cat should be vet checked Asap and spayed or neutered. Be very carefull female cats in heat are very persistant on getting out. Do Not let her sneak out by you.

She has all the symptoms of being in heat! So please do make sure she doesn't get out - she will try anything when in that state. It could last anything from a few days to a couple of weeks. But then it can re-occur within a fortnight during the spring season, until she is mated or spayed. So really you need either to get her spayed quickly or give her to someone who can. It does sound as if she has a good temperament, so I hope you can keep her and that she and the puppy become permanent friends!