The Unique Characteristics That Define Dogs as Mammals

Dogs have all of the attributes to define them as mammals. Man’s best friend has a long history of living alongside humans. Dogs are closely related to foxes, jackals, and gray wolves. Dogs are indeed mammals, but what defines them as such?

These are the traits that make a dog a mammal.

They Give Birth To Live Young

Like other placental mammals, dogs give birth to live young. They gestate between 58 and 68 days. The young are born helpless. For the first two weeks, puppies are fed, cleaned, kept warm, and cared for by their mother. They can pull themselves around in a slow crawl.

At two weeks, puppies will open their eyes and their eyesight will improve over the next several weeks. They will interact with their siblings and mother, and their deciduous teeth will begin to poke through their gums.

They Have Hair

Like other mammals, dogs have fur. Depending on the breed, the hair may be short and thin, long and thick, or somewhere in between. It can be straight, wavy, or curly. Many dogs developed coats for a specific purpose, such as hunting dogs whose coats protect them from underbrush and retrievers who have a waterproof outer coat.

Their Lower Jaw is Made From a Single Bone

The structure of the lower jaw in dogs, like in many mammals, is composed of a single bone called the mandible. The single bone, attached to the skull, gives the jaw incredible power. This makes it easy for the dog to chew and bite. Because of the strength of the jaw, proper training is important to ensure safety for everyone involved, and keep puppies from chewing on household items they shouldn’t.

They Have One Set of Replacement Teeth

Mammals do not continually replace their teeth. Their deciduous, or baby teeth, start coming in when they are between two and three weeks old. These teeth begin to fall out at around 12 weeks, and by six months most dogs will have a full set of permanent teeth, which must last them a lifetime.

They Are Warm-Blooded

Like other mammals, dogs are warm-blooded. This means they can regulate their temperature on their own. Unlike a reptile that needs heat to provide energy for hunting and other movements, a dog’s body can heat and cool itself on its own.

Internal Composition

There are several internal features that all mammals share. While you cannot see these things with the naked eye, they are all part of what makes a dog a mammal. One feature is a four-chambered heart. The four-chambered heart oxygenates blood more efficiently than the three-chambered hearts of reptiles and amphibians and the two-chambered hearts of fish.

Another feature that all mammals have in common is their well-developed diaphragm. While birds and reptiles also have diaphragms, they aren’t as well-developed as the ones in mammals. This allows for more efficient breathing and better use of oxygen.

Finally, all mammals have three bones that make up the inner ear. These bones are responsible for transporting sound waves and transforming them into neural impulses which can be interpreted by the brain as sound.

Closely Related Mammals

Dogs are in the family Canidae. 35 other species make up this group, and they all have a few things in common. Whether you are talking about domesticated dogs or the wild members of the canine family, such as dingoes, foxes, coyotes, and wolves, they all rely heavily on scent for nearly every aspect of their life.

In the wild, these animals use their nose to not only find prey but also recognize predators, find a mate, and avoid trouble. While a domestic dog doesn’t need to do all of these things, they still have a highly developed sense of smell and use it to explore their world.

Many mammals are omnivores, meaning they eat both plants and meat, but many are strictly herbivores or carnivores. Some, such as wolves, are carnivores, and eat only meat. Canines that rely entirely on hunting to meet their nutritional needs often live in social packs, which makes hunting game easier.

The History of Domestic Dogs

Archeological research has yet to pin down the exact time when canines joined with humans and became domestic dogs. What is known is that they are the oldest species domesticated by humans and have probably lived alongside humans as companions for over 15,000 years.

Dogs are believed to be among the first animals domesticated by humans, potentially before horses and cattle, but the exact timeline is still debated. It isn’t certain where dogs were first domesticated, but it was thought to be in Western Europe and Central and Eastern Asia. The beneficial relationship developed from there and continues to this day.