Are cross breeds healthier and more robust than their purebred counterparts? Tim Falk finds out.
The belief that cross-breed dogs are healthier and more robust than purebred canines is widespread in the dog world. It’s influenced many when choosing a family pet, prompting them to go for a hardy cross over a purebred, but is there any truth behind the idea that cross-breeds are healthier than purebred dogs?
“While it has been commonly thought in the past that mixed-breed dogs are healthier than purebred dogs, this is not always the case,” says Dr Gretta Howard from Cherrybrook Vet Hospital. “So-called ‘puppy farms’ can be disastrous if two poor-quality dogs are bred with each other, even if they are different breeds.”
Even so, the concept of “hybrid vigour” does have some weight behind it. Genetic problems are more likely to be phenotypically expressed (displayed rather than just carried in the genes) when closely related animals are bred. With this in mind, the concept of hybrid vigour is definitely true if you directly compare breeding two closely related dogs compared with two unrelated dogs.
“However, the concept of hybrid vigour cannot be directly extrapolated to purebred versus mixed-breed dogs because well-respected registered breeders have a highly controlled program in place and detailed records so that they can select appropriate dogs to breed with one another,” Dr Howard says.
“In fact, breeders will widen the gene pool by ensuring they introduce healthy new stud animals from interstate or even overseas. There are even artificial insemination programs for the less common breeds of dogs which reduce the risk of inheritable genetic diseases even further.”
In a study done by the University of California, Davis in 2013 looked at 90,000 medical records of dogs over a 15-year period. The study revealed that genetic diseases are statistically equivalent in both mixed-breed and purebred dogs. In fact, it was found that a ruptured cruciate ligament was actually more common in mixed-breed dogs.
“To sum it up, there are genetic disorders that are seen at a higher frequency in purebred dogs, but for the most common genetic diseases seen in vet practice, they tend to be diagnosed equally in both mixed-breed and purebred dogs,” Dr Howard explains.
Each pure breed dog has its own set of breed pre-dispositions which place it at a higher risk of inheriting certain conditions. Dr Ben Willcocks from pet health website vetico.com.au says that brachycephalic dog breeds, such as Pugs and French Bulldogs for instance, share breed predilections towards anatomical issues, such as elongated soft palates. German Shepherds and Labradors have a higher likelihood of developing bone and joint issues, such as hip dysplasia, and Cavalier King Charles Spaniels have a predisposition to cardiac issues.
However, responsible registered breeders are doing a lot to reduce the occurrence of hereditary health issues. “Often, there are a number of screening tests and pedigree assessments that can be done to the prospective parents to reduce the likelihood of developing these problems,” Dr Willcocks says.
“Breeders of dogs that have an increased likelihood of developing hip dysplasia, for instance, can get hip scoring done to ensure the parents don’t suffer from hip dysplasia, and thereby the offspring are less likely to develop these problems. And often, for breeders to be registered breeders, they have to abide by these breeding regulations as it is,” he says.
The right breed for you
Leaving aside the debate about whether one type of dog is healthier than another for a moment, it’s important to remember that dogs of all shapes and sizes can have a special place in our heart. For some of us, the dependability of a purebred and the ability to fall head over heels in love with one particular breed is what determines the type of pooches we like to add to our family.
For others, there’s simply so much to love about the humble cross-breed or mutt. “My current dog is a bitser made up of all things white and fluffy,” says Dr Belinda Parsons from drbelindathevet.com.
“I think more often than not you get the best of the bunch with a bitser. You get the energy of one breed, with the coat of another, facial features and expressions of another and a great combined personality that just works.
“I also think many of us love to give a rescue dog a good home. With so many dogs in shelters I think it’s becoming second nature for people to adopt rather than shop for a dog. This means they’ll be looking for lifestyle features in a dog but not necessarily for a breed.”
Regardless of whether you love purebreds, mixed-breeds or simply anything with a wet nose, four legs and a tail, the important thing is that we work towards improving the health of all dogs. When you consider the amount of joy they bring into our lives, this really is the least we can do.
Questions you should ask your breeder
How can you be sure you’re buying a puppy from a breeder who is working to ensure the health of puppies and to improve the future of the breed? Dr Belinda Parsons recommends asking a breeder the following questions before you take home a puppy:
- Have the parents been hip and elbow scored? What type of hip and elbow scoring was performed? PennHip is considered one of the best.
- Can you meet the parents of the puppies? Temperament has a genetic component, so aggressive parents are more likely to result in aggressive offspring.
- Are the puppies and the parents vaccinated and can you see the vaccination records?
- Are they a registered breeder?
- Are they accredited by the appropriate breed society? (This won’t guarantee good breeding habits but hopefully means it is less likely to be a puppy mill).
- If you’re concerned that the breeders are a puppy mill, ask how many litters the mother dog has per year, how old she was when she had her first litter — she should have been at least 18 months old, ideally over two years old before she has a litter. Puppy mills often breed the bitches from eight months old and repeatedly without giving them a break. Responsible breeders care about their bitches and will give them time off between litters and will not breed them to death.
- What is the lineage like for the last three generations of dogs? Do they have a wide gene pool or are the father, grandfather and brother all the same dog?