menstruation of dogs

[vivi]

I have a 9 months old mix dalmation and rottweiler, my question is how long is the duration of her menstruation?

[toyah]

Normally 3 weeks

[ezapf]

True. From what I have read, it can be from 2 to 4 weeks. 3 weeks being normal. I have a 6 year old lab who seems to be at the short end and young pup whose first heat cycle was at the longer end.