?? is stray cat in heat??

Question
i have a stray that i have been trying to save.  she is declawed and litter box trained.  she has been getting more friendly and i hope to take her into the vet to have her shots updated and her checked out.  i have 2 male cats, both about 1 1/2 yrs old(adopted).  we have had "smokey(we believe is female)" in our screen room and decided to open up the sliding glass door.  tux started sniffing her through the screen and then started howling.  is she in heat?  what else could be going on?

thanks, mechelle

Answer
If she's declawed, I'd be very surprised if she's not spayed - those operations are usually performed together.  And if she's spayed, she won't go into heat anymore. However, people don't always make sense, so it certainly is possible she may be in heat.

Personally, I would suspect more that Tux's howling was a warning to her that she's on his turf.  Howling is a noise cats use to communicate with each other, and the message isn't good - it means the cat is ready to fight.  So while you have howling, definitely keep them separated through the screen.  A screen is actually quite the perfect way to introduce cats.  They can get used to one another's appearance and scent without being able to hurt each other.  

Once there's no more howling, you can see how they do without the screen PROVIDED that you have confirmed she's been spayed, or that both of your males are neutered.  I would also highly recommend having her tested for feline leukemia before introducing them, as this is an incurable, terminal viral disease that is pretty easily spread through grooming each other, or maybe even sharing water bowls.