Finances: All dogs are going to cost you beyond the upfront costs - but different breeds carry different price tags, says Gillian Ridgeway, director of Who's Walking Who dog training. Bulldogs, for example, are predisposed to expensive medical conditions, she says. Transportation, boarding, medication and X-rays for larger breeds will be costlier: The bigger the dog, the bigger the bill.
Physical activity: Know who you are and the amount of exercise you get. Don't think a dog is going to change that. If you're a couch potato, avoid the sporting, herding and working breeds. Consider toy breeds such as a pug, Yorkshire terrier or Pomeranian - but know that every dog, no matter the breed, requires daily exercise.
Hair care: Some people don't want to deal with shedding: In that case, a hairless (Chinese crested, for example) or hypoallergenic breed (think poodle or Portuguese water dog) is a good option.
"Personally, I'd focus on getting a dog with a good disposition - and a vacuum," says Ms. Ridgeway.
Family: If you have small kids, research breeds that are better suited for young ones. "Herding dogs - sheltie, border collies - don't always like to be grabbed," says Ms. Ridgeway. "But a chocolate lab? No problem."
Time commitment: All dogs will need training to behave well at home, on a walk and in the dog park, whether you take a class or have someone come to your home. But some breeds need to be mentally challenged more than others, says Ms. Ridgeway. "Border collies need you to teach them something new. … They're clever and have a better chance of becoming destructive out of boredom."
Any dog, she emphasizes, is a serious time commitment. "If you're going to come home from work, let your dog out, then leave - that is not okay. Get a cat."