I went to the vet today, because my old cat is having some health problems. While there I asked the vet about this, because I had planned to take Tila in to get spayed before her first heat too. She's almost 10 months and is now in her first heat. My vet told me, they can do it while she is in heat, but it's more costly and will take longer. She was saying something about the blood vessels. But she told me it would probably be better to wait until she's done her heat before taking her in to get spayed. It'd probably be best to ask your vet to see what they say, just to be sure.
