Dogs are domesticated mammals of the Carnivora order. Descendants of wolves, dogs are the first animals to have been domesticated by humans—roughly 30,000 years ago. Dogs are bred for particular physical and emotional characteristics to assist humans with work and service tasks or to serve as companions, or pets. Dogs are differentiated as either purebred, or pedigree, with parents of the same breed, or as mixed-breeds, mutts, hybrids or mongrels with parents of multiple breeds. Dogs are often referred to as ‘man’s best friend’ referring to the high degree of loyalty that dogs share with humans.

Domestic dogs, beloved companions to many, exhibit a wide range of sizes and shapes, but share common anatomical traits. Their bodies, whether lithe or robust, are built for movement, with muscular legs for running and a flexible spine. Their paws have pads and nails suitable for various terrains. Dogs communicate through barks, whines, and growls, and also convey emotions through body language, especially their tail. Their keen sense of smell is legendary, outperforming our own by magnitudes, and they possess sharp hearing. While their vision is different from ours, with a broader field of view and enhanced night sight, it's adapted perfectly for their needs.

Dogs and humans share a bond tracing back thousands of years, evolving from wolves into our hunting partners and protectors. This age-old alliance has transformed dogs into "man's best friend." Their impact on culture is vast: from ancient legends to modern films like "Lassie" and "Old Yeller," they're celebrated symbols of loyalty and love. Literature, music, and art frequently feature canines, underscoring our shared history.

While most breeds aren't endangered, some face health issues due to overbreeding. Various organizations and individuals champion canine welfare, combating puppy mills, promoting adoption, and ensuring our four-legged companions receive the love and care they've historically given us.