How long?

Once she is bleeding in heat, what's the normal time span? She started swelling around March 18.

I know very little about heat.

An average heat cycle usually lasts 3 weeks. Some have it for only 2, while others, 4 weeks.

Thanks

This should answer your questions

Anatomy and Function of the Reproductive System in Dogs

I always considered 4 weeks to be on the safe side !

Confine your bitch from other dogs for thirty days from the first show of blood.

Another very good educational link about canine reproduction.

http://www.aces.edu/pubs/docs/U/UNP-0052/UNP-0052.pdf

I have kept her isolated in the house (no walks) and in the backyard ONLY under my eye since she first started swelling. I am paranoid about "oops" litters. I don't want any litters. If I had my way, and I hadn't had to promise to show her, she would have been neutered already. My other dog is fixed, so that's not a problem. It's everyone else I have to worry about!!!

Egads.