Dog Breed Info Center(R) DBIC

The Structure of a Dog's Body

A Dog with bowed out front legs is sitting outside on a brick surface with its mouth open and tongue out

Just like humans, the structure of a dog’s body has a lot to do with its general, overall health. For example, if a human's legs are bowed out to the side, bowed inward or the spine is curved, we try and do what we can to correct the structure. Bad bone structure often causes pain and other health problems. This is an accepted fact when it comes to the human body. Not everyone thinks of this when it comes to dogs, however. This page gives examples of good and bad body structure in dogs to help you see what to look for when picking out a puppy. This page only gives general information. Check the standard of your breed to see its accepted bone structure.

The topline is the line formed by the withers, back loin and croup. It is the area from the base of the neck to the base of the tail on a dog. Most breeds are meant to have a level topline, meaning this area is flat. However, some breeds do have an arch that is accepted in their written standard, such as the Whippet.

A Mastiff puppy being posed by its owner

This Mastiff puppy has a good, level topline. The back from the neck to the base of the tail is flat.

A Wet Havanese being posed by its owner

This Havanese puppy has a good, level topline. The back from the neck to the base of the tail is flat.

A Wet Havanese that is standing on a table

This is an example of a bad topline in a Havanese. The back is curved and not level.

The forelegs are the front legs of a dog. The legs in a dog should be straight and not bowed inward or outward. When a dog's legs are bent, just like a human, it can cause health issues such as arthritis.

The front legs of a mastiff standing on a red backdrop

This Mastiff puppy has a good front line. The forelegs are nice and straight.

The front legs of a wet havanese standingon a towel

This dog also has a good front line. The forelegs are nice and straight.

A Beagle is sitting outside in front of a tree and looking towards the camera holder

This Beagle has a bad front line. Notice how the Beagle’s forelegs are bent and not straight. If this dog were human we would consider it deformed.

Max the Basset Hound is standin on concrete and looking toward the right

Max the Basset Hound at 11 years old has a bad front line. Notice how his front paws turn outward rather than face front.

The front Legs of a dog inside of a dog crate

This dog has a bad front leg structure. The legs are bent and not straight.

The front legs of a wet dog standing on a towel

This dog has a bad front leg structure. The legs are bent and not straight.

The hindquarters are the back end of the animal. The back legs of a dog should be straight and not bowed in or outward.

The back end of a mastiff that is standing on a blue backdrop with a person holding its tail up and out of the way

This Mastiff puppy shows a good back end. Notice how the back legs are straight.

The back end of a wet Havanese that is standing on a towel with a person touching them

This Havanese puppy shows a good back end. Notice how the back legs are straight.

The back end of a wet Havanese that is standing on glass on a gray marble countertop

This is an example of a bad rear in a Havanese dog. Notice how the legs are bowed outward and the feet curve into the foot.

The backside of a beagle that is standing on dirt and in front of a chain link fence

This is another example of bad body structure in a hound-type dog. The back legs should be straight, but they curve inward and then turn back outward near the paws.

Koa the Bullypit is sitting outside on a brick surface. Koas mouth is open and tongue is out and his front legs are bowed way out to the sides

Koa the Pit Bull / American Bulldog mix (sometimes called a Bullypit or Colorado Bulldog) at 3 years old—"Koa was born deformed with extreme bow legged-ness. It’s the ankle bone that has the issue, which causes her to walk on her outer feet and makes the curvature so severe looking. There is no surgery that can fix this. I think all of her weight looks like it’s being taken by the enlarged ankle bone area. Koa acted like she was in 7th heaven, happy as can be and totally enjoying my attention and affection. She relished in it. She is a total people lover."

Koa the Pit Bull / American Bulldog mix (sometimes called a Bullypit or Colorado Bulldog) at 3 years old. She was born with a bone structure deformity.

The Bite

A scissor bite is when the upper incisors just overlap the lower incisors, such that the rear surface of the upper incisors touches the outer surface of the lower incisors. An underbite is when the lower incisors extend beyond the upper incisors. An overbite is when the upper incisors overlap the lower incisors, leaving a gap between the teeth.

Most breeds are to have a scissor bite, but some breed standards accept or even consider it normal to have an underbite. It is usually not accepted to have an overbite in a dog.

Close Up Left Profile - the Teeth of a dog. The dog's teeth line up

This puppy has a nice scissor bite. The top teeth meet the bottom teeth.

Close Up front view - a person exposing the teeth of a dog. The dog's teeth line up

Example of a good scissor bite in a puppy

Side view of a person exposing the teeth of a dog. The dog's teeth line up

Example of a good scissor bite in a puppy

Close Up Right Profile - a person exposing the teeth of a dog, the dog's teeth line up

Example of a good scissor bite in a puppy

Close Up - A person exposing the slight underbite of a dog by pulling up their upper lips

This dog has a small underbite. Notice how the top teeth are on the inside of the lower teeth.

Close Up - A person exposing the large underbite of a dog by pulling up the dog's top lips

This dog has a large underbite. The top teeth are so far inward that the dog bites his own tongue. This dog has a hard time holding onto things with this mouth. Underbites this bad should never be accepted by anyone.

Close Up - A person pulling up the lips of a dog to show the severe underbite

Dog with a very bad underbite

Close Up - A dog with crooked bottom teeth

Dog with crooked teeth