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

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.

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


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

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

10 Best Dog Strollers in 2025 – Reviews & Top Picks

Unfortunately, not all dogs are at their peak physically. Elderly, injured, or recovering dogs can be severely limited in mobility. As owners, we...

What Does Raining Cats & Dogs Mean? Pet Idioms Explained

If you’ve heard the expression, “It’s raining cats and dogs,” you may wonder what it means. Rest assured that it has nothing to...

How to Get Rid of Dog Anal Gland Smell: 5 Vet-Approved Tricks

With a scent often described as “fishy,” anal gland smell is not one you’ll want hanging around your dog or house. Whether your...

What Happens If a Dog Licks Human Blood? Vet-Verified Health Risks & Care

If you are a pet owner and have found yourself bleeding or injured, you might have noticed that your dog wants to lick...

More related

Is Coconut Oil Good for a Dog’s Itchy Skin? Vet-Verified Health Facts

Coconut oil is known for its health benefits, and many people either cook with it or use it topically. Some of the benefits...

11 Fascinating German Shorthaired Pointer Facts For Dog Lovers

The German Shorthaired Pointer has an aristocratic and noble appearance, but this dog is no snob. It is enthusiastic, affectionate, and eager to...

My Dog Is Getting Old: Vet-Approved Tips on How to Prepare

You watch as your excitable young puppy slowly matures until they are a stately adult dog, and then one day, you notice a...

9 Best Dog Ramps for Beds in 2025 – Reviews & Top Picks

Many dog owners love to snuggle in bed with their pups, but some dogs can have trouble getting up there on their own....

Keep reading

Can Dogs Have Matcha? Vet-Verified Dangers & FAQ

Matcha can be found in a plethora of food and drink items, from lattes to ice cream. If you’re a fan of occasionally giving your canine companion a treat in the form of human food, you may be wondering if...

Dogster-Can-Dogs-Have-Matcha

10 Best Foods for Husky Puppies in 2025 – Reviews & Top Picks

Siberian Huskies are working dogs who were bred to pull sleds across the tundra, but they’re also affectionate companions that enjoy being around humans and other pets. To keep your Husky puppy healthy, you’ll need to serve a nutritious diet...

young siberian husky eating

Can Dogs Eat Spam? Vet-Verified Nutritional Facts & FAQ

Protein is an important part of a healthy dog’s diet, and there are few protein sources that are as beneficial as meat. Whether you feed your dog chicken, beef, salmon, or other animal-based protein, you can keep your dog healthy...

Can Dogs Eat Spam

Can Dogs Eat Flan? Vet-Reviewed Potential Risks & Safety Guide

Flan is a custard-like dessert that can contain several ingredients. However, it typically contains eggs, milk, and sugar. While dogs can eat a small amount of dairy products like flan, it isn’t recommended. While flan isn’t toxic, it isn’t usually...

Can Dogs Eat Flan

Freeze-Dried Dog Food: 8 Vet-Verified Pros & Cons

Freeze-dried raw dog foods are becoming a popular option because of their high palatability and ability to provide a raw diet rich in vital nutrients. These diets also take the guesswork out of feeding a raw diet, ensuring your dog’s...

Freeze Dried Cat or Dog Food

10 Best Dog Foods for Rottweilers in 2025 – Reviews & Top Picks

Rottweilers may look big and intimidating, but these dogs are gentle giants that are often misunderstood. If you haven’t met this breed before, then you don’t realize how sweet they really are. Aside from their kind temperance, they are most...

Rottweiler puppies eating from a bowl

6 Best Spot and Tango Dog Food Alternatives in 2025: Reviews & Top Picks

When you have a dog, you want only the best for them, from their healthcare to their food. Fresh food subscription services offer some of the best nutrition available for your pooch and, as such, are becoming more and more...

Italian Greyhound dog eating from bowl at home

KOHA Dog Food Review 2025: Pros, Cons & Recalls

Review Summary KOHA Pet Food manufactures premium food for dogs with allergies and food sensitivities. Several things set KOHA apart from most premium dog food brands. First, KOHA doesn’t sell dog food through retail stores like PetSmart or online retailers...

Dogster_KOHA Dog Food Review