|There is a mis-conception that a cross-bred dog is healthier
than a purebred. In truth a cross-bred dog can have all the
health problems that BOTH breeds have instead of just one.
For example the Golden Retriever has high rates of hip
problems. The Standard Poodle rarely does- but the Standard
Poodle can get SA. There for if you breed a Lab to a
Standard Poodle you could get a pup who has BOTH bad hips
|The reason this misconception started is because of several factors:
Most cross bred dogs are products of back yard breeders who do not know better and therefore do not health test
their breeding animals for hidden genetic issues which may show up on their puppies. Nor do back-yard breeders
know the pedigrees behind their dogs. Knowing the ancestors to the dogs you intend to breed AND health testing
must be done to insure healthy offspring.
Regardless of what anyone tells you about testing, there are only a couple of genetic tests for poodles. The genetic
tests for vonWillebrands disease (affects 1% of Standard Poodles) and Progressive Retinal Atrophy, which affects
toys and minis.
There are few, if any, true genetic tests in the other breeds (the ones frequently crossed with poodles) either. If
someone claims differently, they are not being truthful.
A breeder can test hips, skin, eyes, etc etc....but all those tests tell you is that the dog is healthy (or not) on the day
of the test! The tests are not a predictor of the health of any proposed offspring.
The ONLY way to make informed and healthy decisions about breeding is to insure that the parents are healthy by
testing, avoid all inbreeding AND to do research back up to 20 generations.
Most reputable breeders who have worked long and hard to breed better, healthier dogs and who have done
exhaustive amounts of research, are unwilling to let their purebred dogs be crossed with other breeds.
That leaves the cross breeder to pick from backyard bred or puppy mill foundation dogs that don't have in depth
health histories done generations back. Genes for some of these diseases can hide for generations. It is impossible
to create a healthy cross-bred dog without healthy parents from healthy lines. Like the saying goes "Garbage in...
This is being illustrated as a result of the recent popularity of the crossing of the Poodle to the Labrador Retriever
"Labradoodes" (a so-called hybrid).
The OFA (records health issues for various breeds) has recorded Hybrid dogs as being number 26 for hip dysplasia
out of 142 breeds listed. This makes the hybrid worse than the German Shepherd (39), Golden Retriever(32),and
much worse than the two founding breeds: Labrador Retriever (74), Poodle (70).
How is it possible to make a 'breed' worse than the foundation stock breed average??? Because the foundation stock
of the cross bred dog is NOT quality!
Again "Garbage in.... Garbage out!"
Therefore it is safe to say this:
A Pure Bred dog from a reputable breeder is actually healthier than a cross-
| Hybrid Vigor Explained by Karen Peak
The concept of hybrid vigor assumes that a crossbred animal (and this term is most often used in discussing dogs) will be healthier
than a purebred. In reality, this is often false.
In order to be a hybrid, an animal must be the product of two different species: donkey and a horse, offspring is a mule; lion (m)
and a tiger (f), offspring is a liger; tiger (m) and lion (f), offspring is a tigon; wolf and domestic dog, off-spring is called a wolf
hybrid. Remember high school Biology, animal classification: Kingdom, Phylum, Class, Order, Family, Genus, and Species?
Each animal in the crosses mentioned share the same Family (Equus, Felis, Canis) but are different species. The offspring are
hybrids. Domestic dogs are the same species familiaris. When you cross breed domestic dogs (Canis familiaris ), you are within
the same species; therefore, not creating a hybrid.
Hybrids are not problem free. In Ligers, no fertile male has ever been found and necropsies have proven sterility in them. Other
issues in ligers and tigons: ligers may be prone to gigantism and tigons may be prone to dwarfism. Both hybridizations have
shown an increase in cancer rates and decrease in lifespan. (Tiger Territory, M. Annabell, 2001). In wolf/dog hybrids, there are
often behavioral issues. The domestic dog differs greatly in behavior from a wolf. Dogs were bred to be cooperative with humans
while wolves fear humans and try to avoid us.
Even domestic Wolves are far different from dog in terms of behavior. Dogs often accept leadership happily while adult wolves will
fight for leadership within the pack. The wolf/dog hybrid can be a time bomb temperamentally when they hit full maturity. Wolves
also differ from dogs in other ways including: skull structure, nutritional needs, estrus cycles, etc. (Canine Hybrid Issues
Surrounding the Wolf Dog , M. Sloan, J. Moore Porter, 2001)
Returning to the domestic dog: Canis familiaris. A breed is not a separate species, it is just a set of genes specifically bred to
exhibit certain traits like the coat an Old English Sheepdog has or the build of a Rottweiler. With C. Familiaris, we just took traits
An example that may clarify this: all humans are Homo sapiens regardless of color, eye shape, etc. Nature helped develop certain
traits to best suit the environment the H. sapiens were developing in. All domestic dogs are C. Familiaris; we just developed them
into different breeds.
Species is the same but there are differences based on need.
What determines a breed in the loosest sense is that when bred to another of the same breed, you will end up with the same traits.
When you breed a German Shepherd Dog to another GSD, you only get GSDs. You will not get something that looks like a
Labrador Retriever. If you cross a GSD and a Lab, you can get offspring that look more GSD, more Lab or resemble both parents
in varying ways. With purebreds you have a predictable outcome.
With crosses, you do not.
It takes many generations to fix the traits in a new breed – not just four or five. For example, the Shetland Sheepdog, a breed from
the Shetland Isles is NOT a miniaturized Collie. But the Sheltie is a breed that is only about 100 years old – relatively new. Collie
was crossed into the early Sheltie to add to certain traits, but this also added the problem of oversized Shelties – something
breeders have struggled with for many decades to correct due to the infusion of Collie blood into a developing breed.
Crossbred dogs such as the Cock-a-poo are NOT hybrids nor are they breeds. The Cock-a-poo Club of America states in its
guidelines that in order to be a cock-a-poo, that you breed Cocker (American or English) to a Toy or Miniature Poodle. This is not
a breed; it is a cross – a mutt. Cock-a-poos may look very Poodle, very Cocker or somewhere in between.
Even a Cock-a-poo bred to a Cock-a-poo is not a breed. Remember, it can take decades or more to get true-breeding traits – or
to repair damage done when something else is crossed in during the early history of a breed just beginning to come together.
There is research that states the domestication of what we know today as a dog may have started longer ago that assumed –
maybe as much as 100,000 years ago based on mitochondrial DNA studies of wolves and dogs. (The Truth About Dogs, S.
Budiansky, 1999) No one really knows for certain when wild canines began domesticating themselves or we began domesticating
Therefore, the creation of specific breeds is relatively new in the grand scheme of the history of the domestic dog. Bones of truly
domesticated dogs were found dating back to as early as 5,000 BC. Ancient pictures show dogs that were of definite sight hound
type. (Dogs of Ancient Egypt, J. Dunn).
Back to Hybrid Vigor: is it true? No. Returning to the cock-a-poo example. Poodles and Cockers have many of the same
health problems; therefore, a cross of them might actually stand a higher risk of inheriting a problem than a purebred pup from a
Some of the problems in both breeds are: hip dysplasia, progressive retinal atrophy, epilepsy, poor temperaments, allergies, skin
and ear problem, Legg-Calve-Perthe's, luxating patellas, hypothyroidism, cryptorchidism, gastric torsion ( Cock-a-poos, Cindy
Tittle Moore, 1997). Yes, things like ear infections, allergies, temperaments and gastric torsion have hereditary as well as
Now, why did I state a cross might stand a higher risk of a hereditary problem than a dog from a good breeder? Rarely
do people breeding crosses do any health tests – genetic or otherwise. They assume that an annual veterinarian visit and shots are
all that is needed. Maybe for a pet dog, but breeders need to consider the genetic health of puppies produced.
Things such as Hip and Elbow Dysplasia, Luxating Patellas, various eye problems, von Willebrand's (a bleeding disorder) and
Thyroid function are common in many, many breeds and crosses.
The myth that purebreds are unhealthy or nasty came about due to bad breeders who either did not care about health testing or
who were ignorant and felt that dogs who show no outward signs of a problem do not have it.
A purebred dog from a good and educated source has a greater chance of being healthier than a crossbred.
So, the next time you hear about hybrid vigor and how mutts are healthier, remember this: hybrid vigor as related to dogs is a
Hybrid Vigor Myth Explained
|My wonderful cross bred mutt Ayla...
Her body failed her by 7 years old.
She was my wonderful companion and my agility dog.
I miss you Ayla!