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.

How to Tell if a Puppy Is a Boy or a Girl: Vet-Approved Way

Share

veterinarian examining a labrador retriever puppy

While you can’t always tell the difference between male and female adult dogs from a distance, there are physical and behavioral clues that can help. When it comes to puppies, however, especially newborns, it can be a lot harder to tell if a puppy is a boy or a girl.

If you’re dealing with a litter of newborn puppies or just aren’t sure how to determine the sex of your new baby dog, we’re here to help. In this article, we’ll teach you how to tell if your puppy is a boy or a girl and discuss the differences between the two.

divider dog faces oct 2024

Before You Begin

Be cautious about removing newborn puppies from their mother. Some mother dogs are very protective and it’s important to give them time and space to bond with their puppies. While you should keep handling to a minimum for the first few weeks of their lives, you will need to touch the puppies occasionally.

For example, you’ll want to monitor their weight to make sure they’re growing properly and to see if they are boys or girls. Consider having someone else take the mama dog for a short walk in the yard while you check on the puppies if she is especially protective.

Playing puppies
Image Credit: Anita Kot, Getty images

How to Tell if a Puppy Is a Boy or a Girl

1. Don’t Rely on Size

For most breeds, adult male dogs are taller and heavier than females as a breed standard. However, you can’t rely on the size of newborn puppies to tell the boys from the girls.

The birth weight, overall health, and other factors play a role in the puppy’s size. You can’t always assume the bigger babies are the boys.


2. Don’t Rely on Behavior

We’ll discuss some of the behavior differences between male and female adult dogs later in this article. Many of those behaviors are related to hormones and other changes that occur once the dog reaches sexual maturity.

Newborn puppies haven’t undergone these changes yet, so you can’t rely on their behavior to tell you which are boys or girls.


3. Physically Examine the Puppy

To tell if a puppy is a boy or a girl, pick the dog up and look at the belly. At this age, the penis and vulva are similar in size and appearance but are in different locations.

Girl puppies have a visible vulva, often described as leaf-shaped, between their hind legs below the tail. Boy puppies have a penis further up their belly, just below their umbilical area or belly button. These physical features are apparent even in puppies who were just born.

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

dogster paw divider

Why Is It Important to Know if a Puppy Is a Boy or a Girl?

If you’re selling or adopting out puppies, you’ll need to be able to tell new owners the sex of the dogs. Most owners prefer male or female dogs based on past experience, the sex of dogs currently in their family, advice from other dog owners, or general assumptions about the behaviors of the two sexes.

According to research, there are differences between male and female dogs, but the data shows some variability. For example, male dogs are more likely to be aggressive and courageous than females. Females show more fearful behaviors on average but are more inclined towards social interactions with humans that require cooperative skills. Males were more inclined towards social play with people.

However, whether your puppy is a boy or a girl isn’t the only factor that controls how they act. Early socialization and training play a vital role in shaping a puppy’s temperament and behavior as they develop.

If you like to talk with a vet to clear out any other doubts you might have regarding this topic, you can consult one online.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's our online service where you can talk to a vet online and get the advice you need for your dog — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

dogster face divider

Conclusion

Determining if a puppy is a boy or a girl at any age is easy once you know what you’re looking for. Deciding whether a boy or girl dog is the best fit for your family might be a bit harder. As we mentioned, it often comes down to the owner’s personal preference. If you don’t plan to breed your boy or girl puppy, talk to your veterinarian about the best time to have them spayed or neutered.


Featured Image Credit: IgorAleks, 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

What Does a Therapy Dog Do? Facts & FAQ

Every dog owner recognizes the positive impact their pet has on their lives. When they promote them to being therapy dogs, they give...

Is a Labradoodle Hypoallergenic? Vet-Verified Facts & FAQ

Labradoodles are incredibly loyal and friendly, making them ideal for families with kids and the elderly. Since the dogs are easy to train,...

Perfectly Natural Soap’s Good Dog Grooming Starter Set Review 2026: The Perfect Way to Clean your Dog

Just like humans, dogs can suffer negative effects from chemicals and synthetic ingredients added to shampoos, conditioners, and other grooming staples. In fact,...

How Much Exercise Does My French Bulldog Need? Vet Approved Advice

French Bulldogs are among the most popular and desirable dog breeds. They are lively, outgoing, affectionate, and have personalities that are hard to...

More related

Why Does My Dog Have a Favorite Toy? Vet-Verified Behavioral Facts

A dog’s life is filled with simple pleasures—a tasty treat, a walk to their favorite park, a snuggle session with you, and, of...

12 Best Emotional Support Dog Breeds: Descriptions & Traits (With Info & Pictures)

It is not just in modern times that people have been turning to animals for companionship and emotional support. People from all walks...

How Long Does a Swedish Vallhund Live? Vet-Reviewed Average Lifespan, Data & Care Guide

If you have a Swedish Vallhund or are considering getting one as a pet, you should familiarize yourself with the breed and understand...

Bullmastiff vs French Mastiff: Visual Differences & Overview (With Pictures)

If you like big dogs, then you likely already know about Mastiffs. There are multiple breeds that fall into the Mastiff category, but...

Keep reading

Primal vs Stella & Chewy Dog Food: Our 2026 Comparison (Vet-Reviewed)

When you’re shopping through the ever-growing sea of commercial dog food selections, you might come across these two companies: Primal and Stella & Chewy’s. If both brands strike your attention due to their similarities and dog-conscious recipes and you want...

Dogster_Dog Food Primal VS Stella & Chewy

10 Best Puppy Foods for Chihuahuas in 2026 – Reviews & Top Picks

One of the best-known toy breeds, the Chihuahua is a small, energetic dog bursting with personality. Most Chihuahua owners take their dogs everywhere, and they’re ideal “purse” dogs. Chihuahuas have unique energy needs, however. They require a balanced diet for...

two chihuahua puppies eating food from a bowl

Can Dogs Eat Mussels? Vet-Approved Benefits & Safety Tips

Dogs can eat mussels in moderation. Mussels are high in protein and other nutrients that may benefit your dog; however, they don’t provide everything your dog needs, so they should only be considered an occasional treat. It’s best to steam...

Can Dogs Eat_Mussels

Nutro vs Blue Buffalo Dog Food: Our 2026 Comparison

Choosing the best food for your dog can be tricky, given the quality of kibbles available today. Nutro and Blue Buffalo are well-regarded pet food brands that have many fans, not only canine but also human. They both offer a...

Dogster_Dog Food Nutro VS Blue Buffalo

Can Dogs Drink Wine? Vet-Verified Risks & FAQ

If you enjoy relaxing with a glass of wine in the evenings, you might feel inclined to give your dog some. Their adorable begging as you sip the wine could make you question whether a small sip could do them...

Can Dogs Drink Wine

Can Dogs Eat Sunflower Oil? Vet Reviewed Facts & FAQ

Sunflower oil sounds about as natural as it gets. Whole foods have taken root in the dog food market as obesity rates are on the rise, and pet parents have become more knowledgeable about how to care for their fur...

Can Dogs Eat_sunflower oil

Can Dogs Eat Caviar? Vet-Reviewed Nutrition Facts

As dog owners, we want the best for our pets, including what they eat. However, some dog parents take things to the next level by offering their pups gourmet human foods, such as caviar. While dogs can occasionally eat caviar,...

Can Dogs Eat_Cassava

10 Best Wet Dog Foods in Canada in 2026 – Reviews & Top Picks

Choosing the best dog food for your best friend is an essential part of being a dog owner. While kibble has its benefits, notwithstanding the lower price, canned dog food is high in fibre and protein, low in fat, and...

shih tzu dog getting wet food from owner at kitchen

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Dogster Email Newsletter