A medium size dog weighs between 16 and 60 Kilos (35 and 65 pounds) and stand 18 to 25 inches tall at the shoulder. These are the top breeds. Some place more emphasis on weight, others on height.
Labrador Retreiver: AKC Rank #1
There's a reason why the Lab is the #1 dog in the country: the breed's personality, temperament, intelligence and size makes it a trusted companion and excellent family dog. The Labrador Retriever is most commonly black, tan and chocolate brown. The coat is water resistant and sheds seasonally. Labs love to be with people. Take a Labrador Retreiver to water and he's in his element.
Beagle: AKC Rank #5
Tri-coloured hound, bred for hunting rabbits. They make great family pets. They need lots of exercise; otherwise, they'll find ways to keep themselves busy, which will likely involve the destruction of family property. They are highly social, so if your beagle is an only dog, crate training is advised or else they can get into trouble. Beagles are scent hounds and can track a scent for miles. It is not advised to let a beagle off leash except in fenced areas.
Boxer: AKC Rank #6
Boxers have tremendous heart, energy and intelligence. They love people, especially children. Boxers are classified as working dogs and are excellent watchdogs. They make wonderful companions when they have access to regular, and hard-working, exercise.
Bulldog: AKC Rank #7
Bulldogs make excellent family pets due to their reputation for forming strong bonds with people. They don't need a lot of exercise and are easily trained. Because of their short nose, Bulldogs can easily overheat, so they can't be left outside or in homes without air conditioning.
Standard Dachshund: AKC Rank #8
Dachshunds get their shape from decades of breeding to hunt badgers. They are affectionate and love to be around people. They are playful and need moderate exercise to stay happy and healthy. The Dachshund coat can be smooth, wiry or long, requiring regular grooming.
Miniature Poodle: AKC rank #9
Don't let the name fool you. A miniature poodle stands 10 inches to 15 inches tall at the shoulder and is technically medium size. Hypoallergenic coat makes them a great option for owners with dander allergies. Energetic and athletic. Requires daily exercise. Needs regular grooming. Good in nearly every living situation.
Shetland Sheepdogs: AKC rank #18
Shetland Sheepdogs, commonly known as Shelties, are loyal companions. Their loyalty can make them wary of strangers, but when properly introduced are welcoming. Shelties are herding dogs, so they need lots of exercise and a "job" to keep them from getting into trouble. Professional grooming is required to ensure the breed's double-coat doesn't get matted.
American Cocker Spaniel: AKC Rank #23
Cocker Spaniels continue to be one of the top medium dog breeds due to their excellent disposition and desire to be around people. They are intelligent and easy to train. Cocker Spaniels are hunting dogs and require daily exercise to burn off their natural energy. The longhair coat requires professional grooming.
Pembroke Welsh Corgi: AKC Rank #26
The Pembroke Welsh Corgi is bred as a cattle dog. They are hard working and thrive in outdoor activities. The breed, a favourite of Queen Elizabeth of England, is not to be confused with the Cardigan Welsh Corgi, which has a long tail and sturdier bone structure. Corgi's have outgoing personalities and enjoy spending time with people.
Basset Hound: AKC Rank #34
Basset Hounds are immediately recognisable by their long ears. They come in tricolour and two-tone colours. Bassets are intelligent and can be equally as stubborn, so training requires persistence and patience. They are deceptively athletic and do well with lots of exercise. These scent hounds can track for miles, so keep the dog on a leash.