Jack russel -

Question
I have a female Jack Russell who will be 1 year this month, I've had her since she was 6 weeks, i have read many articles which say that they should start the bleeding around 6-8mths. My JR has not yet shown any signs of bleeding is this normal. The only sign is that she like to mount a specific teddy and go for it but she does this every day since she was around weeks.
Is their any reason why she hasn't started, she is a very slim and petite dog for her age can this contribute

Answer
Hello,
6 weeks is much too early for a puppy to be away from it's mother and siblings. That could be one of the reasons she is so slim and "petite". My puppies don't leave her until they are 10 weeks old. This is a public forum and it's my goal to try to educate people which is why I wanted to mention that - thank you -
To answer your question, 6-8 months to begin the estrus cycle is an "average" only. Every dog is different, one of my dogs didn't go into her first season until she was 18 months old. Your dog, who is still practically a puppy herself, might not go into heat for another year, but I assume it will be soon. Also, you may have read about "silent heats" where the dog is actually in heat but shows no signs of it.  NO dog should be bred during their first heat cycle; it is always best to wait until the second one.  Mounting stuffed animals, peoples legs, etc. is just the dog trying to show dominance and has nothing to do with breeding whatsoever. Hope this helped!