Despite their close genetic relationship and the ability to inter-breed, there are a number of diagnostic features to distinguish the gray wolves from domestic dogs. Domesticated dogs are clearly distinguishable from wolves by starch gel electrophoresis of red blood cell acid phosphatase.[41] The tympanic bullae are large, convex and almost spherical in gray wolves, while the bullae of dogs are smaller, compressed and slightly crumpled.[42] Compared with equally sized wolves, dogs tend to have 20% smaller skulls and 30% smaller brains.[43]:35 The teeth of gray wolves are also proportionately larger than those of dogs.[44] Dogs have a more domed forehead and a distinctive "stop" between forehead and nose.[45] The temporalis muscle that closes the jaws is more robust in wolves.[5]:p158 Wolves do not have dewclaws on their back legs, unless there has been admixture with dogs that had them.[46] Most dogs lack a functioning pre-caudal gland and enter estrus twice yearly, unlike gray wolves which only do so once a year.[47] So-called primitive dogs such as dingoes and Basenjis retain the yearly estrus cycle.[48]
According to statistics published by the American Pet Products Manufacturers Association in the National Pet Owner Survey in 2009–2010, it is estimated there are 77.5 million people with pet dogs in the United States.[152] The same survey shows nearly 40% of American households own at least one dog, of which 67% own just one dog, 25% two dogs and nearly 9% more than two dogs. There does not seem to be any gender preference among dogs as pets, as the statistical data reveal an equal number of female and male dog pets. Yet, although several programs are ongoing to promote pet adoption, less than a fifth of the owned dogs come from a shelter.
^ Jump up to: a b Axelsson, E.; Ratnakumar, A.; Arendt, M.L.; Maqbool, K.; Webster, M.T.; Perloski, M.; Liberg, O.; Arnemo, J.M.; Hedhammar, Å.; Lindblad-Toh, K. (2013). "The genomic signature of dog domestication reveals adaptation to a starch-rich diet". Nature. 495 (7441): 360–364. Bibcode:2013Natur.495..360A. doi:10.1038/nature11837. PMID 23354050.
Take extra care with dark-nailed dogs not to clip to the quick (blood vessel). Go slowly, and only take a little bit off at a time. Dremeling is much safer and easier to avoid hitting the quick, as it shaves only a little bit at a time. Use a cordless pet-safe Dremel tool, as the corded ones will not stop turning if they catch hair. Don't dremel for too long as it will burn the nail and prolong the trimming process for the dog which causes more stress. The best recommended process is trim first then dremel to shorten a little bit and round out the nail do it's not sharp.

A number of common human foods and household ingestibles are toxic to dogs, including chocolate solids (theobromine poisoning), onion and garlic (thiosulphate, sulfoxide or disulfide poisoning),[54] grapes and raisins, macadamia nuts, xylitol,[55] as well as various plants and other potentially ingested materials.[56][57] The nicotine in tobacco can also be dangerous. Dogs can be exposed to the substance by scavenging through garbage bins or ashtrays and eating cigars and cigarettes. Signs can be vomiting of large amounts (e.g., from eating cigar butts) or diarrhea. Some other signs are abdominal pain, loss of coordination, collapse, or death.[58] Dogs are susceptible to theobromine poisoning, typically from ingestion of chocolate. Theobromine is toxic to dogs because, although the dog's metabolism is capable of breaking down the chemical, the process is so slow that for some dogs even small amounts of chocolate can be fatal, especially dark chocolate.

Amongst apprenticeship programs and other hands-on training activities, Petco pet stylists who are trained from within the company are required to attend and pass Petco's comprehensive 12-week Pet Stylist Apprentice & Certification academy program. In addition to hands-on grooming training with a Petco-certified pet stylist mentor or instructor, all participants receive instruction in health, safety protocols and grooming salon operations. At the end of the program, candidates must pass a technical skills assessment in order to become a Petco Certified Pet Stylist.