After hundreds of years of breeding, an incredible number of varied breeds exist, from the smallest Chihuahua to the biggest St. Bernard.
Several breeds can be lumped into categories based on their size, so what are some of the biggest differences between large breed and small breed dogs?
Big dogs tend to have shorter lifespans
Big dogs age faster and are more likely to develop cancer than smaller dogs, with toy breeds sometimes living twice as long as giants like Great Danes. A study of over 56,000 dogs and 74 different breeds found with every 4.4 pound increase in weight, a dog's life expectancy decreases by about a month.
Small dogs eat less
Because of their size, big dogs require more calories to maintain their weight and are usually more expensive to feed than small dogs. It's not unheard of for a Great Dane to eat 14 cups of dry food a day on average, while an adult Chihuahua might only eat half a cup or less.
Since food is one of the biggest – or at least the most constant – dog-related expenses, it's worth keeping in mind that the costs associated with feeding a large dog can add up quickly.
Big dogs generally need more exercise
Although every dog needs at least some exercise to stay fit and happy, large breeds tend to need more than their small counterparts.
If you're looking for a canine companion who will joyfully join you on hikes in the woods or long jogs through your neighborhood, a big dog like a German shepherd or a Labrador retriever is more likely to have the boundless energy to match your own. If you're more of a couch potato, many small breeds such as pugs and bulldogs are happy with far less exercise.
Small dogs are perceived to have more behavior problems
Small dogs certainly have a reputation for being a little rambunctious, or even yappy. Do they deserve the bad rap? Studies have shown some of this difficult behavior might be genetic – but training also plays a big role in shaping any dog's manners. Still, if you're considering getting a small breed, bear in mind that they'll need just as much (if not more) training, boundary-setting, and socialization as a big dog if you want them to be well-behaved.
Big dogs usually need more space
While there are exceptions to every rule, small breeds often require less space (both indoor and outdoor) and are happier in apartments compared to the typical large, high energy dog. As long as they're given adequate exercise and opportunities to relieve themselves, small dogs are often perfectly content without a fenced yard to frolic in or a large house to explore.