Most vets say 6 months in the UK and prefer to perform the op when they are not in heat although I don't think it's a huge problem if they are in heat. Our Milly and Ruby had their ops just before 6 months and I recall one of them was in heat. Ruby I think.
I certainly recall Milly being in heat from 5 months. What a tart! She wouldn't leave poor Fred alone
![Embarrassed :-[](https://www.purrsinourhearts.co.uk/Smileys/purrs smilies/blush.gif)
He didn't know where to look
![Shocked :shocked:](https://www.purrsinourhearts.co.uk/Smileys/purrs smilies/catshocked.gif)
Good job he was nutless
![Wink ;)](https://www.purrsinourhearts.co.uk/Smileys/purrs smilies/wink.gif)
![](http://i264.photobucket.com/albums/ii191/Rosella100/CIMG44861600x1200.jpg)