The Myth of the Healthy Designer Dog
How often have you heard it said that designer breeds are healthier than pedigree breeds, even claiming a hybrid vigour from the cross, a statement that seems accepted at face value, and justification for any number of first cross matings. Any investigation will show that this is not the case. Most inherited diseases are potentially in the genetic make-up of all dogs with the exception of very rare breed specific conditions like von Willebrands Disease, a blood clotting disorder, in Dobermans.
For example, Hip and Elbow Dysplasia are common to all larger, heavier dogs and may be (almost certainly are) exacerbated by poor rearing including over-feeding and excessive exercise during the growth period. Precisely how much environment and hereditary factors count isn’t known, but this certainly isn’t a breed exclusive to pedigree dogs.
Progressive Retinal Atrophy is another serious inherited disease, as are other eye diseases causing blindness, that is common to all dogs.
How Inherited Diseases Work
- Dominant Inheritance – only one parent needs to carry the gene to potentially affect a puppy
- Recessive Inheritance – both parents need to carry the gene to potentially affect a puppy
Neither parent need necessarily show any sign of disease, either at the time of breeding, or ever. These dogs are known as carriers and can only be detected through health screening.
Labradoodles and Goldendoodles
The mix of Labradors or Retrievers with a Standard Poodle brings together an inheritance pattern of hip, elbow and eye problems. Breeders of Labradors and Golden Retrievers should screen dogs they are breeding from for:
- BVA/KC/ISDS + AHT/ECVO Eye Schemes and BVA/KC Hip SchemeBVA/KC Elbow Scheme - which cover a range of eye problems, Hip and Elbow Dysplasia
Standard Poodles should be screened by a responsible breeder for:
- BVA/KC/ISDS + AHT/ECVO Eye Schemes and BVA/KC Hip Scheme – again, like the Retrievers, Eyes and Hips
Any responsible breeder of these two crosses should be able to show certificates showing the dog’s scores and results. Hip and Elbows are scored at 2 years old and Eyes are tested annually in all breeds and up to the age of 8 in Labradors to detect late onset hereditary cataracts.
Cavalier King Charles Spaniels Crosses
This is a popular breed for crossing – Cavachon and Pugalier come to mind – but has a terrible health record. Syringomelia, a devastating condition where basically the skull is too small for the brain causes great pain and is virtually untreatable; the inheritance mode isn’t yet known, but what is definite is that it is inherited.
Cavaliers also suffer to an unacceptable level from Mitral Valve Disease, a heart problem which ultimately causes heart failure and death. Half of all Cavaliers are affected by the age of 5 years and virtually all by the age of 10. A breeding protocol was introduced to eliminate it in the UK in 1996 but this has not been observed, making any cross using a Cavalier potentially extremely unhealthy. The majority of Cavaliers will die of heart failure, a disgraceful situation when the breeders have a protocol to address this defect.
In addition, Cavaliers should be screened for eye problems under the BVA/KC/ISDS + AHT/ECVO Eye Schemes. Poodle mixes of all sizes should also be examined under the Eye Scheme.
There are other reasons for buying a mixed breed dog, but don’t be taken in by the myth that they are healthier than purebred dogs, and do ask the breeder what health screening they have done and ask to see the results. If they have tested their dogs appropriately then they are to be congratulated; if not, then they are acting irresponsibly and not in the best interests of the puppies they are breeding.