Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

At What Age Do Dogs Reach Sexual Maturity? What Science Says!

cardigan welsh corgi puppy

Like children, puppies grow and mature way too quickly. One minute you are delighting in the “puppiness” of your new addition, then before you know it, your adorable pup is on the sofa humping away at the pillow.

Unfortunately, they do not stay puppies for long, and most dogs become sexually mature between 6 and 9 months old. It can vary, however, according to the size and breed of the dog.

divider single dog paw oct 2024

When Do Puppies Reach Sexual Maturity?

The age of sexual maturity for your pup will depend on the size and breed of your dog. While the average age is between 6 to 9 months, a small breed male dog can be fertile and sire pups as young as 5 months old. However, most dogs become fully fertile at around 12 to 15 months old, and giant breeds may not be sexually mature until they reach 12 to 18 months of age.

Since spaying and neutering your dog can alter hormones that aid in healthy bone growth, many veterinarians do not recommend having the procedure done until the canine’s growth plates close. This usually occurs by the time a dog reaches 9 to 11 months of age.

What Happens as Your Puppy Reaches Sexual Maturity?

As your pup begins to hit sexual maturity, hormonal changes may affect their behavior and personality. These changes will differ between males and females.

Female Dogs

Signs that your sexually mature female is in heat include a swollen vulva, frequent urination, and licking of the genital area. The dog will have a red vaginal discharge which resembles a woman’s period for 7 to 10 days, but the fertile time for a female dog can last up to 3 weeks.

The first female heat can begin between 6 and 15 months of age, depending on the individual breed. Although a female can get pregnant during her first heat, it is not recommended. During this time, it is important to watch her closely and keep her on a leash when outside until she gets spayed. Otherwise, you can end up with an unwanted pregnancy.

Dog Heat Cycle
You are free to use this image but we do require you to link back to Dogster.com for credit

Male Dogs

Male dogs are most fertile after they reach 12 to 15 months of age. They can make puppies as young as 5 months old, however. Males are full of testosterone and sexually active all year round at this stage of sexual maturity. As a result, other dogs may begin to show signs of aggression if they sense elevated levels of testosterone, and this can also be a frustrating time for pet parents since males may start to urine-mark their surroundings, even in the home.

At this stage of sexual maturity, both male and female dogs are known to begin to wander away from the house in search of a mate and should be closely monitored, leashed, or contained.

Neutering and Spaying

You’re welcome to use our images, but we require you link directly to this site for credit (ex. Image from Dogster)
You’re welcome to use our images, but we require you link directly to this site for credit (ex. Image from Dogster)

Once your dog reaches sexual maturity, you will need to decide when to have the dog spayed or neutered. Most veterinarians will recommend having the procedure done unless you plan to show or breed the dog. However, some vets will recommend having a male neutered before sexual maturity, and others will advise you to wait until he is 7 to 15 months of age.

When to have your female pup spayed will depend on the individual dog. It is important to wait until she is finished growing and has completed one heat cycle. Otherwise, you run the risk of orthopedic problems in the future.

According to the American Kennel Club (AKC), “Research results have shown that early spay or neuter (before the age of 12 months) can impact the incidence of different types of cancer, hip dysplasia, and development of canine cruciate ligament ruptures.”

Since having your pet spayed or neutered is an individual decision, you should discuss any concerns with your veterinarian. Then, you and your vet can make the best decision that is best for your dog.

Did you know you can talk to a vet online? Click on the image or button below to schedule a call: PangoVet_Mention-in-Content Savings V1


divider dog paws 3 oct 2024

Conclusion

Sexual maturity in dogs is inevitable. It is important to identify the behaviors associated with sexual maturity so you can avoid unwanted pregnancies. Whether you have a female dog in heat or a male that is humping and marking everything in sight, you will need to decide if you are going to have the dog fixed. It is recommended that you discuss any growth concerns with your veterinarian prior to scheduling the procedure so you can prevent orthopedic problems in the future.

See Also: 


Featured Image Credit: Liliya Kulianionak, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Red and Red Fawn French Bulldog: Info, Pictures, Origin & History

Standing only a foot tall and built like a tank with their signature bat ears, the French Bulldog is one of the most...

Chemotherapy for Dogs: Costs, Side Effects, & What to Expect (Vet-Approved)

Finding out that your dog has cancer is a heart-dropping moment. Although it can be a heavy diagnosis, it’s important to know what...

Do Puppies Need Puppy Food? Vet-Verified Facts & FAQ

When you stop to really think about it, it may seem like a no-brainer that puppies would need different food from our adult...

Is a Mini Goldendoodle Hypoallergenic? Vet-Verified Facts & Allergy Care Tips

If you’ve been looking into giving a Mini Goldendoodle a forever home but have dog allergies, you might wonder if the dog is...

More related

100+ Airedale Terrier Names: Ideas for Classy & Graceful Dogs

If you’ve just adopted an Airedale Terrier, you have a big decision ahead of you: what on earth should you name your pup?...

11 Signs Your Dog Wants to Go for a Walk: What to Watch-Out For

If your dog is like most, they’re always looking to go for a nice, long walk. But sometimes, they’re a little more adamant...

My Dog Feels Neglected After We Had a Baby: 5 Vet-Approved Ways to Help

No matter how well you plan, every baby comes with an adjustment period, and it isn’t just the parents who feel the immediate...

Do Pugs Make Good Pets? Info, Traits & Tips

Pugs are those adorable, flat-faced, snorty dogs we all know and love. You see them everywhere, and sometimes you hear them before you...

Keep reading

7 Best Nom Nom Dog Food Alternatives in 2025: Reviews & Top Picks

Nom Nom is a dog food subscription service. You sign up, choose your dog food and delivery rate, and you can have dog food delivered to your door. It provides the benefits of feeding a freshly made diet, combined with...

dog eating wet food

Can Dogs Eat Rice? Vet-Verified Nutrition Facts, Benefits & Risks

Rice is a staple food found in almost every kitchen worldwide, and there are many different varieties to choose from! If your dog is eyeing your rice-based meal, you might wonder if it’s safe for your dog to eat rice....

Can Dogs Eat Rice

10 Best Non-GMO Dog Foods in 2025: Reviews & Top Picks

There are so many different types of dog foods on the market. From “grain-free” to “holistic” to “human-grade,” how do you choose the best one for your canine pal? Many marketing terms are used on dog food labels nowadays, and...

Gizmo white fluffy dog with Ollie dog food box

Can Dogs Eat Raspberries? Vet-Verified Nutrition Facts & FAQ

Although dogs are facultative carnivores, many enjoy snacking on fruits and veggies and they can provide additional health benefits. However, it can be tricky for dog parents to remember which fruits are entirely safe for canines. For example, can dogs...

Can Dogs Eat_Raspberries

Can Dogs Eat Carrots? Vet-Approved Nutrition Facts & FAQ

While we all love a tasty treat occasionally, we often wonder if the foods we’re snacking on are safe to offer dogs, especially when they look at us with those pleading puppy-dog eyes. If you are a carrot fan or...

Can Dogs Eat Carrots

20 Best Dog Food Affiliate Programs in 2025 – Reviews & Top Picks

Caring for a pet dog is one of the most fulfilling things you can do. They are great companions and help us learn a thing or two about love. In the U.S., the number of pets has increased overwhelmingly to...

Golden Retriever dog eating

Can Dogs Have Chia Seed Pudding? Vet-Reviewed Health & Nutrition Guide

Chia seed pudding is a delicious vegan snack made by soaking chia seeds in plant-based milk. It’s often enjoyed as a breakfast or dessert and pairs well with fruit. If you enjoy eating chia seed pudding, you may be wondering...

two fruit with Chia Seed beverages on glass cups

8 Best Low Sodium Dog Foods In 2025 – Reviews & Top Picks

There are tons of dog foods out there—so much so that some pet stores have almost half of their floor space dedicated to it. One type of dog food that doesn’t get a lot of coverage, though, is low-sodium dog...

Dalmatian dog eating dry food from a bowl