There are approximately 78 million dogs owned in the United States. And 53% are mixed dogs, which means their parents and family members were different breeds. That means many new owners, rescues and animal shelters must guess what breeds their dogs are! But how a dog looks isn’t always the answer.

Dogs evolved from the grey wolf. Humans bred dogs by selecting specific traits (like the type of fur, color, size, intelligence or speed). As different qualities were chosen, each new generation of pooches grew different from the rest. On top of that, different parts of the world bred dogs for different traits, causing dogs to change even more.

The grey wolf and all breeds of pet dogs are still the same species. However pet dogs have become a sub-species, and dog breeds are a further classification within the species (think of your golden retrievers, collies, pugs and more!). Breeds can be defined as a group of animals that all look similar.

You may have also heard about “designer breed” dogs where a few dog breeds were mixed on purpose to create a certain quality, like non-shedding fur—one example is the “doodle,” which may be a retriever and a poodle. What’s the difference between a mutt and a designer breed? The answer is nothing, as they are both mixed breeds!

Why may it be important to know what breeds make up a dog? Lots of reasons! Certain breeds can get health issues, so you want to know what to watch out for when you bring home that kind of dog. Plus, it can help estimate a pup’s size when he is an adult dog, and give you an idea of the kind of activity level and enrichment a dog may need. (For example, some dogs may be eager to learn and enjoy lots of training classes.)

You can test your dogs’ DNA at home to find out what breeds are in them with a simple kit purchased online or in a pet store.