Labs are hands down the most popular domestic breed. In many respects they are the quintessential family dog; loyal, good with kids, friendly but big enough to make a burglar think twice, and long-lived. They do need room to play so a yard or frequent trips to the dog park are ideal. They also love water! They do shed seasonally, so regular brushing is necessary. As they age, labs are prone to hip dysplasia and arthritis, and frequently suffer knee ligament injuries in middle age. For a large breed dog, labs have a fairly long life-span up to 12-13 years, so geriatric issues, urinary incontinence, cognitive dysfunction (dementia), hearing loss, and heart problems are not uncommon.

German Shepherd dogs, or GSD for short, are a perennial top dog on the AKC most popular breed list. Loyal and intelligent, these guard dogs are great for families and do well with children. Their large size and exuberant nature may mean you want to keep a close eye if you have small children, just to avoid any tumbles, and their sweeping tail can clear a coffee table in the blink of an eye. Because the breed standard for GSDs states that they should have sloping hindquarters, they are prone to hip dysplasia, and like any large breed dog, frequently suffer knee ligament injuries. As they age, German Shepherds are also often predisposed to heart disease.

The epitome of the family dog, Golden Retrievers are beautiful and friendly, this intelligent breed is frequently trained as service dogs. They are smart, gentle, and loyal dogs that perform the tasks they have been assigned flawlessly. They are calm yet friendly in nature and are known to adapt to new situations and socialize into various environments. Their ability to learn quickly and retain information over a while is incredible. Goldens do well with children and are great house dogs, but their long coat does need frequent brushing to avoid matting and help with shedding. They are also prone to hip and knee injuries as well as heart disease and GDV.

Tiny chihuahuas pack quite a punch for their five-pound average weight. They are devoted to their owners and tend to gravitate or lay claim, to one member of a family. Because of their small size and sassy temperament, they are not an ideal choice for families with young kids. Since they don't require much exercise, though, they are great apartment dogs. The shed seasonally and don't require frequent grooming. Like other small breeds, chihuahuas commonly have a genetic condition called the luxating patella, which means their knee caps pop in and out. The condition can cause problems with mobility but can be surgically repaired.