This is one of the most difficult questions to answer, as all dog breeds will have their own health issues, so to advise on the healthiest dog breed is near enough impossible.
Buying a mongrel or crossbreed doesn't always guarantee you a healthy dog. Research does show that smaller dogs do tend to live longer, but this does not mean that they don't come with their own health issues.
Unfortunately, the vast majority of dog breeds have been bred for aesthetics rather than behaviour, although this is now starting to change. Mongrels and crossbreeds are thought to be the healthiest of dog breeds as they come from a wider gene pool. Again,this doesn't always mean that they don't come with their own health issues.
It's always worth understanding that you shouldn't choose a particular dog breed based on their future health. You should also consider whether they would fit into your life and home.
Following on from this, below is a list of dog breeds that are less likely to suffer from health issues. It is important to understand that this list is based on an opinion and must not be subjected as true to every dog in this particular breed.
Siberian Husky
The Siberian Husky is dog breed that is known to have fewer health-related issues in comparison to other dog breeds. They are prone to potentially developing hip dysplasia and diseases in their eyes. They make great family pets because of their gentle, loving temperament.
Foxhound
The Foxhound has shown not to have as many health issues as other dog breeds and is often rarely affected by genetic disorders. They are prone to obesity if not fed and exercised properly. They do require lots of exercise and make excellent companions.
Border Collie
This is another breed that is considered to be normally very healthy. This dog breed is on the larger side, so can develop hip dysplasia. Regular exercise and correct supplements can help combat this. The Border Collie is very intelligent and athletic.
Beagle
The Beagle is normally a healthy dog if given the correct treatment and healthcare. They are prone to becoming obese; a healthy diet and plenty of exercise should help to prevent this. Their long ears are prone to sometimes becoming infected. This dog breed is less prone to hereditary diseases in comparison to other dog breeds.
Maltese
The Maltese are known to have hardly any serious health conditions. Tear staining can sometimes occur, but this isn't known to be life threatening. Their coats are pure white and the dog is in the smaller size range. They're an affectionate breed and very playful. Making them wonderful family pets.
Lakeland Terrier
As with many dog breeds, terriers are prone to health issues, including issues with their eyes, joints and skin diseases. The Lakeland Terrier is normally thought to be a strong, hardy breed of dog, living up to 16 years of age.
Japanese Shiba Inu
This breed of dog is normally considered to be on of the healthiest dog breeds. They are very independent and extremely clever, They often live between 12 - 15 years.
