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When does a large breed dog typically go into her first heat?

Updated on September 23rd, 2025

Pet's info: Dog | Labrador Retriever | Female | 1 year and 7 months old

What range should one expect a large breed canine to experience her first estrus?

1 Answer

Most Helpful Answer

Answered By Dr. Strydom, DVM

Veterinarian

Published on December 10th, 2017

Average age for the first estrus in a large breed dog is about 6-9 months of age. It is not usual for large breeds to not have their first heat until somewhere between 12 and 18 months of age. So, as you can see, it varies widely when a large breed dog may go into heat for the first time. Some dogs come into heat and don't outwardly show any signs so you may not even notice their heat cycle.

My best recommendation is that if you have a breeding bitch that is 18-19 months old and she has not had her first heat cycle, you should have her evaluated by a reproductive veterinarian to make sure she is sound for breeding.

Hope this helps. Best wishes.

1Pet Parents found this answer helpful

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