Is my baby ok?

I have a russan blue (mixed with something else) I took her to the vet almost a week ago. She was in heat, and just came out yesterday. The vet gave her the first shots, and gave her some revolution. In the spot where he put it, there is now no hair. It's really weird. It wasn't like that yesterday, but today there is a spot on her neck that is bald. She stays inside, so she didn't get into a fight or anything. She's about 2 years old (the vet told me) and her nose is warm and a bit dry, it could have been because she's been laying on the bed. For the past two days she's stayed in the bed and hasn't really been running around. While she was in heat and before she would be all over the house, now she's just in the bed. She does get up and eat and stuff. is it just a by product of being in heat? I am going to call the vet tomorrow, but I'm just looking for your thoughts to ease my mind. I just noticed the patch today when I came home, so it happened sometime today. It's about dime size and where her hair was is now BRIGHT wite, a little in a pin size spot, but she won't let me look at it much. She doesn't like being held. Do you think she's ok? What do you think could be wrong?

I'm not expert in the whole, cats being in heat thing, and I'm not sure about the revolution causing, but right now... I would say it's possible that either one of those two things could cause her to act this way, (or any number of other things.) Someone else can handle that part of the post.

But I do have one question, why haven't you spayed your beloved cat? Specially if she's a mix, so he's obviously not top purebred breeding material.

I haven't had her all that long. I got her in December and because she was a stray from the pound I waited a few weeks until she was comfy with us before I took her to the vet the first time. And when I took her the fist time she was in heat. So, she kinda beat me to that. The vet said he wanted to do it in 3 weeks. (She has another round of shots then too) I am going to do it, I just haven't been able to yet.

Hi Harley's mom-

This is actually a common side effect to using Revolution. The hair loss and white powdery residue is temporary and will be better in a few days. The lethargy is also a side effect of the flea treatment. If you are really concerned, I would take her temperature- you really can't tell by touching ears, nose or paws if a cat is running a fever. If she is running a fever, then I would call a vet and talk to him. But all that you are describing is common for this product.

Next time, try Frontline- it is a bit milder and effective on fleas.

You are a gem! Thanks! The vet put that on her, but he won't next time. Thanks a lot!