Do dogs menstruate and how?

No, dogs do not menstruate, instead they go through "estrus" or "heat cycles" - meaning they are also fertile during these periods - approximately twice a year and last around 21 days. The dog may...

Here's a little more information about what I am talking about. My menstrual cycle has always been like clockwork. I've never been late by more than a day, but for some reason it was a full week...

Yes, and normally he tries to jump up and shoot right for the owners crotch region. This is a very normal behavior for dogs, but with preventative care and attack the crotch.

No, this is often one of the most common reasons for spaying. Not only will it make for a happier healthier dog (if you are not intending to breed/show her) but it will stop the menstruation.