Sexual Maturity and Reproduction in Dogs

Females can start to become pregnant between 6-10 months old. Males aren't sexually mature until they're 1.
Sexual Maturity and Reproduction in Dogs

Last update: 20 October, 2018

There have been many debates about sexual maturity and reproduction in dogs. There are also lots of opinions about when exactly a dog reaches sexual maturity and the best time for mating. Today, you can find out everything you need to know about the topic.

Canine Sexuality

It’s also worth mentioning that dogs have a very different concept of sex than humans. You might hear things like how if a female doesn’t give birth she’ll get cancer, or how neutering a male makes them depressed, or we’re taking away something that’s only natural for them.

None of those things are true. Dogs have a very clear idea of sexuality, which is intended for reproduction. They might enjoy themselves in the moment, but that’s an instinctive reaction to the stimuli. So, when dogs look for a mate, they do it for reproduction purposes only, not pleasure.

In spite of all the supposed drawbacks, spaying and neutering can prevent a lot of problems, such as breast cancer in females and aggressive behavior in males.


Two Jack Russel terriers mating

Sexual Maturity and Reproduction in Dogs: Females

Females reach sexual maturity between 6-10 months old, which is the first time they go into heat. However, that’s the general age range, there are some cases where it doesn’t happen until they’re 1.5 years old.

There are multiple phases to heat:

  • Proestrus. Takes place before she is ready for mounting, but has already started to bleed and spread pheromones.
  • Estrus. The next phase starts 7-10 days after the bleeding. This one lasts 9 days and is the phase where she’s ready to mate.
  • Metestrus. This phase only happens if she has gotten pregnant. It’s the one that involves fertilization, pregnancy, and milk production.
  • Anestrus. This is the last phase in reproduction. It begins with birth and ends with her bleeding at the beginning of her next heat cycle.

Sexual Maturity and Reproduction in Dogs: Males

Males generally take a bit longer because they reach sexual maturity at the age of 1 year. It doesn’t matter how old they are when they reach it: once they have, they’re always ready to mate.

Lady holding a litter of puppies

Once a male notices a female in heat, they’ll smell each other, but she’ll only accept him if she’s in the estrus phrase. If she is, she lifts her tail and turns around to show him her private parts as a sign to allow mounting. Her body then secretes pheromones and cause the male to get an erection.

In general, a female will become pregnant after mounting and give birth to the puppies a few months later. A puppy will need to stay with their mother and siblings for at least 2-3 months. That way they can socialize properly.

Hopefully, this article has cleared up all your doubts about sexual maturity and reproduction in dogs. There are all kinds of myths out there, but now you have a definitive answer to your questions.

Remember, if you want your dog to have puppies, then you have to take responsibility for them once they’re born. They’ll need a home with owners who love and care for them too!

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.