|Incest, or inbreeding is forbidden on moral and legal grounds in most human cultures but
the prohibitions also make sense on from a biological sense.
Inbreeding depression is the loss of viability or function resulting from inbreeding. The
signs of inbreeding depression most easily identified as reproductive failures. These
reproductive failures may show themselves as stillborn and deformed offspring, small
litters, low sexual libido in the parent dogs, low sperm count in males while females may fail
to get pregnant, have unusually small litters, or exhibit poor mothering ability.
Inbreeding depression may also manifest itself as poor health, temperament problems,
mental health disorders, and reduced ability to learn new tasks.
Inbreeding depression can be manifested as a high frequency of immune-mediated
diseases, significantly higher incidence within a line or breed of one or more diseases than
is seen in the species as a whole, or even things as subtle as dogs that seem to catch
every illness that comes along. In some cases, a very inbreed lines may go extinct
|"In general, the average poodle inbred less than 6% will outlive those inbred over 25% (10
generation calculation) by about 3
John B. Armstrong PhD
|”…the breeding of purebred dogs is akin to [breeding laboratory mice]…[most breeds] are
becoming progressively more inbred. My observation is that most are on the road to
extinction, but most breeders do not even realize they are part of an experiment.”
John B. Armstrong, PhD
|Another Good Reason for not inbreeding: Low Genetic Variation:
Genetic variation is the raw material of evolution. Without genetic variation, a population cannot evolve in
response to changing environmental variables and, as a result, may face an increased risk of extinction. For
example, if a population is exposed to a new disease, selection will act on genes for resistance to the disease
if they exist in the population. But if they do not exist—if the right genetic variation is not present—the
population will not evolve and could be wiped out by the disease.
As an endangered species dwindles, it loses genetic variation—and even if the species rebounds, its level of
genetic variation will not. Genetic variation will only slowly be restored through the accumulation of mutations
over many generations. For this reason, an endangered species with low genetic variation may risk extinction
long after its population size has recovered. Evolutionary theory suggests that, for the long-term survival of a
species, we need to conserve not just individual members of a species, but also a species’ ability to evolve in
the face of changing environmental variables—which means conserving individuals and genetic variation.
When a species loses too many individuals, it becomes genetically more uniform and less adaptable to
changing ecological conditions. Now one may ask what this means to domesticated pets? Well if there was a
deadly disease introduced and the population of dogs lacked genetic variation there is a very good chance
very few dogs would survive the epidemic. Genetic Variation is vital in ensuring our breeds survival.
So what does this mean to the Standard Poodle and us here at Paris Poodles? As one of the breeds biggest
fans and one of its breed wardens we accept the responsibility of ensuring the breed has a future. We will
simply not allow our breed to go extinct.
|Why inbreeding Rarely occurs in Nature
Wild species of all kinds employ a number of behavioral strategies to avoid inbreeding. If Nature does
something so consistently, you can bet there is good reason. Among social animals, the young of one or both
genders may disperse to form or join other groups. Dominant breeding males may hold their position only a
short time. Solitary animals tend to be territorial, at least in breeding season, with a male’s territory
overlapping that of several females. Their offspring must disperse and seek territory elsewhere, sometimes
traveling long distances to do so. But even in nature, conditions are occasionally such that an animal has no
choice but to mate with a relative.
Islands that are well away from the nearest mainland gain species only rarely, when a very few individuals
arrive through some accidental circumstance. If they survive the initial inbreeding depression they adapt to
their new environment, sometimes to the point of forming entirely new species as can be seen with the
finches and tortoises of the Galapagos Islands. But because island species have such a narrow genetic
foundation they are highly susceptible to anything that changes their environment. Native Hawaiian species
have been severely impacted and many driven extinct by their inability to adapt to the presence of species
that accompanied early Polynesian migrants as well as more recent introductions by American, European and
The Standard Poodle is lucky to have begun with many founders. This means there should be many dogs to
choose from to avoid inbreeding. However, our breed, like most others, has experienced historic inbreeding
stemming from the choices made by recent generations of breeders who have used one sire more than
others or frequently sought the output of a particular kennel.
Lab mice are arguably the most inbred of domestic mammals; so much so that members of a strain are near
clones of one another. This extreme inbreeding is necessary so researchers will know exactly what to expect
from that particular strain.
Strains are developed by breeding mice brother to sister for many generations, producing levels of inbreeding
unheard of in dog circles. But there is a price to be paid for this. In 20 generations, 80% of the lines
descendant from the original pair will have gone extinct due to lethal health problems or an inability to
reproduce. Even those that make it through the genetic bottleneck are hardly the mice their ancestors were.
Take any pair of field mice put them in a laboratory cage and they survive very well, living longer than they
would in the wild. Take any pair of lab mice and put them in a field and their “wild” life expectancy is zero.
They are suitable only to the very controlled environment of a laboratory, where the “weather” never
changes, food, water and housing are provided and there are no predators.
|The level of inbreeding is usually measured using a formula called Wright’s Coefficient of
It calculates the probability that genes may have been inherited from both sides of an individual’
s pedigree. It is far too complex to do by hand over more than two or three generations, but
some of the better pedigree software will calculate coefficient of inbreeding (COI) for you.
The usual 3-5 generation pedigree won't give sufficient information for a useful calculation.
The best indicator for calculating inbreeding COI is 10 generations. (Going back 10
generations represents 1024 ancestors)
Modern breeders should know the COI of each of their dogs and determine what the COI will
be on planned litters.
Standard Poodles average around 18%. (This is roughly equivalent to all of them being half-
brothers and sisters. Some of the tops stud dogs in the Show World average over 25% or
more!) This is unacceptable!!!
Any mammal whose COI is over 6 % is inbred.
|Although inbreeding in dogs has had very little study from the scientific community;
This theory of inbreeding as been proven, in ALL OTHER SPECIES studied, to be a faulty and deadly.
|Effects of Inbreeding in Standard Poodles - By Dr. Armstrong
There are a small but growing group of dedicated breeders who are refusing to inbreed their beloved dogs.
Paris Poodles is a dedicated breeder who refuses to inbreed.
|What does this graph show?
Therefore an inbreeding COI of less than
6.25% should be the MAXIMUM
acceptable inbreeding Coefficient!
|Inbreeding has been extensively studied in other species.
The professionals in those areas also agree that a low inbreeding COI is imperative:
|Inbreeding in Cattle:
TRAIT PERCENTAGE WHEN INBREEDING DEPRESSION OCCURS
Milk Yield 3%
Calves born 4%
Calves weaned 10%
In Holsteins a 10% increase in inbreeding has been shown to decrease milk production by about 270kg
Just a 1% increase in inbreeding (that is, a 1% increase in the probability that a calf receives the same
gene from both parents) results in a measurable decrease in milk quantity and quality, shortening of
productive life, and increase in calving interval in studied breeds of cattle.
|Strive to keep inbreeding below 5% per generation. As the coefficient of
inbreeding (COI, the degree of relatedness) increases in a flock,
inbreeding depression may occur, during which fertility, growth, and
other reproductive traits tend to decline. Such declines are especially
dramatic when the COI reaches or exceeds 30%.
|Inbreeding in St. Croix Hair Sheep:
|Inbreeding In Race Horses:
A number over 10% indicates too much inbreeding and generally such
horses don't do well at the track.