The practice of using dogs and other animals as a part of therapy dates back to the late 18th century, when animals were introduced into mental institutions to help socialize patients with mental disorders.[201] Animal-assisted intervention research has shown that animal-assisted therapy with a dog can increase social behaviors, such as smiling and laughing, among people with Alzheimer's disease.[202] One study demonstrated that children with ADHD and conduct disorders who participated in an education program with dogs and other animals showed increased attendance, increased knowledge and skill objectives, and decreased antisocial and violent behavior compared with those who were not in an animal-assisted program.[203]
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]
Wolves kill dogs wherever they are found together.[111] One study reported that in Wisconsin in 1999 more compensation had been paid for losses due to wolves taking dogs than for wolves taking livestock. In Wisconsin wolves will often kill hunting dogs, possibly because the dogs are in the wolf's territory.[111] A strategy has been reported in Russia where one wolf lures a dog into heavy brush where another wolf waits in ambush.[112] In some instances, wolves have displayed an uncharacteristic fearlessness of humans and buildings when attacking dogs, to the extent that they have to be beaten off or killed.[113] Although the numbers of dogs killed each year are relatively low, it induces a fear of wolves entering villages and farmyards to take dogs, and losses of dogs to wolves has led to demands for more liberal wolf hunting regulations.[108]
The scientific evidence is mixed as to whether companionship of a dog can enhance human physical health and psychological wellbeing.[191] Studies suggesting that there are benefits to physical health and psychological wellbeing[192] have been criticised for being poorly controlled,[193] and finding that "the health of elderly people is related to their health habits and social supports but not to their ownership of, or attachment to, a companion animal." Earlier studies have shown that people who keep pet dogs or cats exhibit better mental and physical health than those who do not, making fewer visits to the doctor and being less likely to be on medication than non-guardians.[194]
The majority of contemporary dog owners describe their pet as part of the family,[146] although some ambivalence about the relationship is evident in the popular reconceptualization of the dog–human family as a pack.[146] A dominance model of dog–human relationships has been promoted by some dog trainers, such as on the television program Dog Whisperer. However it has been disputed that "trying to achieve status" is characteristic of dog–human interactions.[150] Pet dogs play an active role in family life; for example, a study of conversations in dog–human families showed how family members use the dog as a resource, talking to the dog, or talking through the dog, to mediate their interactions with each other.[151]

In domestic dogs, sexual maturity happens around six to twelve months of age for both males and females,[17][68] although this can be delayed until up to two years old for some large breeds. This is the time at which female dogs will have their first estrous cycle. They will experience subsequent estrous cycles semiannually, during which the body prepares for pregnancy. At the peak of the cycle, females will come into estrus, being mentally and physically receptive to copulation.[17] Because the ova survive and are capable of being fertilized for a week after ovulation, it is possible for more than one male to sire the same litter.[17]

This article was co-authored by Pippa Elliott, MRCVS. Dr. Elliott, BVMS, MRCVS is a veterinarian with over 30 years of experience in veterinary surgery and companion animal practice. She graduated from the University of Glasgow in 1987 with a degree in veterinary medicine and surgery. She has worked at the same animal clinic in her hometown for over 20 years.
Humans would also have derived enormous benefit from the dogs associated with their camps.[136] For instance, dogs would have improved sanitation by cleaning up food scraps.[136] Dogs may have provided warmth, as referred to in the Australian Aboriginal expression "three dog night" (an exceptionally cold night), and they would have alerted the camp to the presence of predators or strangers, using their acute hearing to provide an early warning.[136]
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.
Pets with special needs: Our salon safety protocol is maintained to the highest safety standards. Express service is available for pets who prefer to be hand dried only. For pets with flatter faces (also known as brachycephalic), your stylist will recommend this option as this will greatly decrease the amount of time your pet will spend in the grooming salon, and may be a better option for the health of certain breeds. Please note that we cannot accept wolf hybrids at this time, due to vaccination limitations.