Where the domestication of the dog took place remains debated, with the most plausible proposals spanning Western Europe,[9][28] Central Asia[28][29] and East Asia.[28][30] This has been made more complicated by the recent proposal that an initial wolf population split into East and West Eurasian groups. These two groups, before going extinct, were domesticated independently into two distinct dog populations between 14,000 and 6,400 years ago. The Western Eurasian dog population was gradually and partially replaced by East Asian dogs introduced by humans at least 6,400 years ago.[28][2] This proposal is also debated.[2]

Brush the dog's teeth.[2] Ideally, brushing your dog’s teeth every day with dog toothpaste is the route to healthy teeth and gums. Use dog toothpaste instead of human products, so you don't poison your dog with fluoride. If there is any chance that you may get bitten by your dog, do NOT attempt to brush your pet’s teeth. At any point, if the dog gets overwhelmed, give him a break to calm down.

Clip the dog's hair methodically.[9] You can place the blade against the body safely, so long as you don't press the blade strongly into the skin. Brush against the direction of hair growth(back-brush) before running the clippers the other direction; with the direction of hair growth. Using the clippers against the growth of hair will have the same effect as back-brushing, but will leave a shorter length than the clipper blade that you are using. If you want to shave against the growth of hair, a blade size gets two blade sizes smaller when cutting against the grain. For example, when cutting with 4# against the grain check how long a 7# leaves behind when cutting with the grain. Move the clippers surely, but slowly across the dog's body to remove the hair — moving too fast might leave uneven lines. Always move the blade with the direction of the hairs' growth unless you want a shorter length than your blade claims to leave. Begin at the neck, then move down to the shoulders, under the ears, and toward the chin, throat, and chest areas. DO NOT use a size seven or any skip blades around the throat area or any flaps on the body that can fit between the teeth, such as the Achilles' tendons, arm pits, genital area, tip of tail, or anus. Then, clip the dog's back and sides. Finally, clip the hair on the dog's legs. Be careful when cutting the neck with any blade as it's the most dangerous to cut. Never cut straight down, do so at angles to avoid flaps you can't see in the neck getting cut.
Dog behavior is the internally coordinated responses (actions or inactions) of the domestic dog (individuals or groups) to internal and/or external stimuli.[94] As the oldest domesticated species, with estimates ranging from 9,000–30,000 years BCE, the minds of dogs inevitably have been shaped by millennia of contact with humans. As a result of this physical and social evolution, dogs, more than any other species, have acquired the ability to understand and communicate with humans, and they are uniquely attuned to human behaviors.[18] Behavioral scientists have uncovered a surprising set of social-cognitive abilities in the domestic dog. These abilities are not possessed by the dog's closest canine relatives nor by other highly intelligent mammals such as great apes but rather parallel some of the social-cognitive skills of human children.[95]

In 2013, an estimate of the global dog population was 987 million.[104] Although it is said that the "dog is man's best friend",[105] this refers largely to the ~20% of dogs that live in developed countries. In the developing world, dogs are more commonly feral or communally owned, with pet dogs uncommon.[50] Most of these dogs live their lives as scavengers and have never been owned by humans, with one study showing their most common response when approached by strangers is to run away (52%) or respond aggressively (11%).[106] Little is known about these dogs, or the dogs in developed countries that are feral, stray or are in shelters, because the great majority of modern research on dog cognition has focused on pet dogs living in human homes.[107]
Try to avoid getting shampoo into your dog's eyes. It could seriously irritate them. Put shampoo into your hands before spreading it into your dog's fur instead applying it straight from the bottle. Don't let suds get into your dog's eyes when rinsing, and gently squeeze his ears shut to keep water out when working on those areas. You can place cotton balls in your dog’s ears to prevent water from getting into the ear canals. Make sure to remove the cotton balls when you're done. You may also keep the cotton balls in during the drying process as the noise of the dryer scares them.

A common breeding practice for pet dogs is mating between close relatives (e.g. between half- and full siblings).[81] Inbreeding depression is considered to be due largely to the expression of homozygous deleterious recessive mutations.[82] Outcrossing between unrelated individuals, including dogs of different breeds, results in the beneficial masking of deleterious recessive mutations in progeny.[83]
The breed with the shortest lifespan (among breeds for which there is a questionnaire survey with a reasonable sample size) is the Dogue de Bordeaux, with a median longevity of about 5.2 years, but several breeds, including miniature bull terriers, bloodhounds, and Irish wolfhounds are nearly as short-lived, with median longevities of 6 to 7 years.[64]

Experienced pet stylists hired from outside the company must complete a personal skill evaluation by a Petco Certified Pet Stylist or Grooming Salon Leader, as well as four weeks of safety and pet grooming operations training. They must also complete and pass a technical skills assessment within 14 days of hire. If the candidate does not pass the technical evaluations, they must complete Petco's 12-week Pet Stylist Apprentice & Certification program and retake the skills assessment.