My female dobie who is now 15months has not had a season. I have kept a watchful eye on her from the age of 6 months and nothing at all. When she was 1 years I mentioned this to my vet and she told me not to worry it will happen. 5 months later nothing. I am thinking about taking her back to the vet. Can anyone help me with this. Why is it taking so long, is there any possible cause or problems relating to this. She is a very fit, energetic dog. Eats well and basically healthy and in tip top condition. I would like her to be spayed but prefer her to have her first season.