Hello, my sister is about to pick up a rescue in the next hour and he's 15 weeks, but she's just realised her bitch is in heat....is it safe or is he old enough to mate her....obviously if he is she'll have to postpone....please advise....thanks

Yes he is, he may not be fertile but he can and no doubt will perform the actions, probable encouraged by the bitch.

I see what you're saying, but is that a problem, in its self....or just harmless?? Is he too young to castrate? My sister could keep them apart for a few days....

She would have to keep them apart for three weeks at least. I doubt a vet would castrate him at that age, and even if he was castrated it would be a few weeks before he could be considered sterile.

Would be strongly against castration at 15 weeks old, 15 months may be ok depends on what breed or cross he is. He or the bitch could be damaged if they attempted to mate and there is always a chance that he may be fertile.

thanks to all for replies...my sis has decided against it, for obvious reasons, and he has another home to go to, thank goodness. thanks again