A very liberally edited version of an article by Jerold S. Bell, D.V.M.
that appeared in the September 1992 American Kennel Club
Gazette, "The Ins and Outs of Pedigree Analysis, Genetic Diversity,
and Genetic Disease Control"
... followed by some
Without exception all breeds of dogs are the result of
inbreeding. Inbreeding has either occurred through natural
selection among a small isolated population (i.e. the dingo) or
through the influence of man breeding selected animals to derive
specific traits. Either way intensive inbreeding is responsible
for setting enough of the dominant traits that the resulting
group breeds true to type. At which point a population of dogs
can be said to be a breed.
Dogs actually have more genes than humans. Tens of
thousands of genes interact to produce a single dog. All genes
are inherited in pairs, one from the sire and one from the
dame. If the inherited genes from both parents are identical
they are said to be homozygous. If the pair of inherited genes
are not similar they are said to be heterozygous. The gene
pairs that make a German Shorthair breed true to type are
obviously homozygous. However, variable gene pairs like those
that control coat color, size, scenting ability, etc. are still
heterozygous within the breed as a whole.
Linebreeding concentrates the genes of a specific ancestor
or ancestors through their appearance multiple times in a
pedigree. When a specific ancestor appears more than once
behind at least one animal on both the sire's side and
yet another animal on the dame's side
homozygosity for that animal's traits are possible.
However, if this specific ancestor appears only through a
particular offspring of the ancestor
in question then the Breeder is actually breeding on this
offspring of the ancestor rather than
on the ancestor
itself. This is why having many "uncovered crosses" to a
specific ancestor ( those that come through different offspring
of this specific ancestor) gives the Breeder the greatest chance
of making the desired traits of the specific ancestor
Homozygosity greatly improves the chances that the resulting
pups will in turn pass on the desired traits of the specific
ancestor to their pups. When selecting pups from a line breed
litter the Breeder must choose pups that display the desired
traits of the specific ancestor or they have accomplished
little. In fact, if these traits are not present in a linebred
pup it is very likely that it inherited its genes from the
remaining part of its pedigree and will be unable to
breed true to type. Because the Breeder selected “out” for the
pups that didn’t display this original
Inbreeding significantly increases homozygosity, and
therefore uniformity within a litter. One of the best methods
of evaluating how successful a linebreeding has been is to gauge
the similarity of the littermates as compared with pups of other
litters with similar pedigrees. Considerable similarity among
littermates tells the Breeder the genes have "nicked" or paired
together as anticipated. The resulting pups will likely be able
to pass these genes to the next generation.
Undesirable recessive genes are always masked by a dominant
gene. Through inbreeding a rare recessive gene can be passed
from a common ancestor on both the sire and the dame's side
creating a homozygous recessive offspring. The resulting
offspring actually displays the trait neither of their parents
displayed ( even though both of them carried it ). Understand
that inbreeding does not create undesirable genes it simply
increases the chance that traits which are already present in a
heterozygous state within the breed will be displayed.
Too many Breeders outcross as soon as an undesirable trait
appears, blaming the problem on breeding "too close." Nothing
could be further from the truth. In fact out-crossing insures
that the undesirable trait will be carried generation after
generation in a heterozygous recessive state only to rear its
ugly head again and again. Therefore the Breeder who turns away
from breeding “close” is simply passing a known problem on to
succeeding generations and future Breeders.
When an undesirable trait is "unmasked" the Breeder who does
his breed a real service is the one that stays with his line
long enough to rid it of the undesirable trait. By controlling
which specimens within their line are used for breeding in
succeeding generations this Breeder can eliminate the
undesirable trait. Once the recessive gene is removed it can
never again affect the Breeder's line. Inbreeding doesn't cause
good genes to mutate into bad genes it merely increases the
likelihood that they will be displayed.
The Inbreeding Coefficient (or
Wrights coefficient) is an estimate of the percentage
of all variable genes that are homozygous due to inheritance
from common ancestors. It is also the average chance that any
single gene pair is homozygous due to inheritance from a common
ancestor. Our pedigrees display the Inbreeding Coefficient for
each dog in the first 4 generations of a specific dog's
ancestry. Each Inbreeding Coefficient is calculated from that
dog's 10 generation pedigree.
NOTE: Inbreeding does not cause good genes to somehow
mutate - it only increases the likelihood that existing genes
will be displayed - allowing the Breeder the chance to eliminate
what had previously been unseen in their particular line
although it was always present.
At Westwind GSPs we gauge the amount of homozygosity in an
animal using their Inbreeding Coefficient (or
Wrights Coefficient) -
which can be seen as an estimate of the percentage of all
variable genes that could be inherited from common ancestors.
It is also give us a mathematical value for the average chance
that any single gene pair is homozygous due to inheritance from
a common ancestor.
Our pedigrees display the Inbreeding Coefficient for each
dog in the first 4 generations of a specific dog's ancestry.
However, the Inbreeding Coefficients displayed for each dog in
our pedigrees is in turn calculated from that particular dog's
10 generation pedigree. We can trace most of our dogs back more
than 20 generations – some as far back as 35 generations.
Four generation pedigrees that contain 28 unique ancestors
for the 30 positions in the pedigree would obviously generate a
low inbreeding coefficient. Yet a ten generation pedigree for
the same dog might look quite different. If this dog
were to have say 700 unique ancestors
filling the 2048 positions in the pedigree the results for the
same dog would be a much higher and truer inbreeding
coefficient. Sometimes what appears to be an out-bred mix of
genes in the first few generations (especially with owners
naming their own dogs) ends up being a fine example of
linebreeding when the pedigree is extended.
However, it must be remembered that simply knowing the
inbreeding coefficient of a dog does nothing to help us
understand which ancestors the dog is actually bred on. We
know that the animal in question has many crosses to the same
ancestors but we don't know which ancestors they are. To
understand this, and to unlock the secrets of a dog's pedigree,
we must do a homozygosity study.
A homozygosity study is not a percent blood
calculation. The percent blood of a dog and its immediate
ancestors is relatively easy to estimate but not that
important. In fact the dog will have 50% of
its blood be from it sire and 50% of its blood be from its dame.
But if these two dogs have no common ancestors the inbreeding
coefficient would be 0%. Homozygosity is far more
important in determining what traits a dog is capable of passing
on to its offspring than percent blood but
it is extremely difficult to calculate without the use of
So while knowing a dogs inbreeding
coefficient is important in accessing its
potential to throw its type we still need to clearly
understand which dogs behind a
are the most influential. Simply knowing how homozygous
a particular animal is does nothing to help the
conscientious Breeder understand this.
To understand this and to unlock the secrets of a particular
dog's pedigree we must do a homozygosity study. We need to know
which ancestors the dog in question is bred on.
On more than one occasion we have seen pedigrees in which
the most influential ancestor for a homozygous trait doesn't
even appear in the first three generations. In this type of
situation it is not unusual for this particular ancestor to
contribute 50% of the homozygous genes
of the dog in question. In this case if a dog is 16% inbred one
ancestor would be responsible for 8%
or 50% of the dogs homozygosity. It is
of paramount importance for the dedicated Breeder to know not
only the inbreeding coefficient for the resulting litter
before the mating is done but also which dogs in the pups
pedigree are influencing their genetic
Far too many matings have been done only on the basis of
physical appearance with little if any regard to the sire's and
dame's respective pedigrees or the interplay between the two.
Novice Breeders don't realize that individual dogs may share
desirable traits but inherit them differently. This is
especially true of polygenic traits, such as ear set, bite, or
length of forearm. And many Breeders fail to understand that
breeding dogs which are phenotypically similar but genotypically
unrelated won't produce the desired traits in the current litter
- and will actually reduce the chance of these traits
being reproducible in the next generation.
Conversely, individual German Shorthairs with the same
pedigree do not inherit exactly the same genes and will not
breed identically. Dogs in a litter are no more similar than
brothers and sisters in a human
family. Think about it. If dogs have more genes than people and
they are as dissimilar as human siblings need we worry so much
about the “too close” we hear sounded
by all those who know little or nothing about linebreeding.
At Westwind GSPs we regularly breed
litters with a Wright’s Coefficient of more than 20% with
superior results. There have been
examples in German Shorthairs of fine animals
with inbreeding coefficients as high as 65%.
The secret is that all linebreedings must be made on
a combination of performance, appearance and ancestry.
If a Breeder is going to be successful in solidifying a certain
trait they must rigorously select breeding specimens which
display the desired trait and have similar pedigrees.
In so doing Breeders have a chance of making this
desired trait homozygous over time. This is the one key to
successful linebreeding that is most often missed by
In choosing a line of dogs within any
bred it is wise to choose a line with "critical mass". Find a
line within your breed where the most prepotent individual was
mated many times and produced many superior offspring. Without
enough genetic diversity it will be more difficult to find
animals within the line that do not
also share the faults of the pre-potent individual. These are
the faults the Breeder will have the most difficulty in
No matter how limited the critical mass the Breeder must
never breed animals that are poor examples of what the
Breeder is trying to produce simply because they share
common ancestors. Breeding
“paper” is the quickest way to ruination and is largely
responsible for the negative attitudes people have toward
linebreeding. To a Breeder no dog is worth
more than what it is able to produce. No amount of titles
can overcome an animals inability to reproduce its own great
traits. Look at the lack of production from Secretariat.
Most beginning Breeders suspicion they should start with a
brood bitch of a particular line and they are
correct. If at all
possible the new Breeder should obtain
females that come not just from the same important stud but
actually come from the same Motherline that is behind the stud
in question. Instead of trying to get a
bitch as close to the stud in question look for a
pedigree in which the mothers of the sires are themselves from
the same genepool. This is the female who
will likely produce great pups.
In all mammals the females are "X" "X" and males are "X" "Y"
which means that only females carry the genetic code particular
to the part of the gene string that is missing in all males.
Horse Breeders refer to it the "X Factor" and have demonstrated
that the gene responsible for the large heart so many great
racing stallions have can be traced back thru their motherlines
to a single mare that lived more than 100 years ago. If a
stallion has an oversized heart - like Secretariat - this
particular mare will show up in his motherlines over and over
again. The mares themselves don't have the large heart but they
carry the gene for it on their “X” chromosome.
Like wise the stallions do not throw the
large heart themselves.
And so it is with German Shorthairs. The bitches are far
more important than the studs in carrying particular genes
forward. Understand that this is true even if the genes most
sought were originally found in a pre-potent male. The key for
any successful Breeder is to isolate those females that carried
his traits and breed off of them. It has been our experience
that many important traits are indeed sex linked and carried by
the dames from generation to generation.
Successful Breeders realize they are fighting "the drag of
the breed," which is the tendency for all animals to breed back
toward mediocrity. If it didn't work this
way super species and super
races would have developed long ago in every animal on earth.
For instance in human beings it is
impossible to breed parents with high IQs together to produce
higher IQs. Even when two genius
have children the average IQ of their
children will be half way between normal and the average of
By the way Einstein himself was the off
spring of parents who were themselves first cousins
- and he married his first cousin. So much for the tails
of woe you heard in school about the effects of inbreeding.
In fact the history of the German Shorthaired Pointer is replete
with many examples of intensive inbreeding that produced some of
the more influential dogs in our breed.
Unsuccessful Breeders regularly
overlook an animal that has a great trait because it also has a
minor fault in favor of an animal that has no faults but no
great traits. Successful Breeders use specimens within their
line that have at least one truly great trait and breed
them with specimens that in turn are great where the other dog
is weak. This is the "secret to line
breeding" - the only way to successfully fight off the drag of
In so doing it is possible to linebreed offspring that are
better than both the sire and the dame.
Mathmatically fully ¼ of the resulting pups have the
possibility of getting the great
traits from both parent. Plus, the
resulting specimens in turn can pass these
great traits on to the next generation, unlike the F1 hybrid
animal that results from outcrossing that
carries the same traits. This
is how a successful Line
Breeder can actually improve his line as he condenses his
So much is made about the perceived problem of a limited
gene pool in pure bred dogs it has caused some "experts" to
advocate out-breeding of all dogs. However, studies in genetic
conservation of rare and endangered
species have shown this practice
actually contributes to the loss of genetic diversity.
If we were to uniformly out-cross all "lines" in any breed we
would eliminate the differences between the lines and therefore
reduce the diversity between individuals within the
breed. The process of breeding toward genetic purity of any
particular line of German Shorthairs will in fact contribute to
genetic diversity within the breed itself.
In fact what few people understand actually happens is that
as a line is successfully bred over the years
a concentration of good recessive genes
is happening. Assuming the Breeder is a person of
integrity and doesn't knowingly breed animals that have
disqualifiable faults or traits. Over
a period of time this Breeder will clean up his genepool. While
it is true that linebreeding gives the opportunity for the worst
traits to display themselves in any
individual animal, it is not true that the Breeder is required
to use that animal in his genepool. In fact if the Breeder is
concerned with his genepool and not just
about producing pups he actually has the opportunity to
clean up genes that would go unnoticed in an outcross breeding.
What actually happens in a successful linebreeding program
is that over the years the dominate genes in the line tend to
lessen in number. This is because unless a dominate gene was
selected out for in each successive animal
it can never "reappear" in the same way that
a recessive gene can. Obviously if neither of the
parents displays this dominate gene then none of the offspring
can - because it no longer exists in the
Dominant genes are either displayed or they don't exist.
And it should be noted by any serious Breeder that the
"Original Animal" his particular line
was built on was the only animal in his line to carry all
of the dominate genes originally possible. From that point in a
truly closed breeding program there is only the chance that the
number of dominate genes will decline as they are
slowly being replaced on each point of
the gene string by recessive genes. There is no other
possibility unless a breeder outcrosses.
Therefore if the Breeder isn't skillful in accessing and
selecting offspring they will lose some of their precious
dominant genes over time. Often we hear Breeders say they are
“needing an outcross” - what they are really saying is that they
have lost their original dominant genes and have no other means
of getting them back. These could be some of
the most cherished traits of the Fountainhead Animal.
If possible it is wise for you as a lineBreeder to freeze
semen on old stud dogs in your genepool who are known to throw
the dominate genes you value. This gives any Breeder the
ultimate insurance policy - the ability to "outcross" within
their own genepool if they were unfortunate enough to lose
valued dominant genes over time. We have made
good use of frozen semen on a number of occasions.
One of the more interesting things about a linebred genepool
is that it is difficult if not impossible to pass
a linebreeding program on to another
Breeder. Lets assume that you have put
in the work and made the difficult decisions not to use
certain specimens (even those with
highly touted titles and awards)
because they pass on undesirable genes.
Let's assume you have managed to clean up
your genepool. At
the point another Breeder is lucky enough to bred to some of
your best specimens it will improve
virtually anything the other breeder has.
Unfortunately, while those who
outcross to your line will improve
their genetic structure the genes
of your inbred line will tend to
vanish because these genes will very
likely be more recessive than the outcross
genes. In effect the outcross
genepool will "cover up" your more recessive
inbred genes. And there is not much either breeder can do about
it - even if you wanted to.
Unfortunately many breeders do this to themselves.
We have seen this many times over the years especially from
those who think they can "buy their way in."
The fallacy in their thinking is that
they can buy a line breed brood bitch from one line and a
line bred brood bitch from yet another
line to breed to their great new Stud
Dog – often their first German Shorthair. They think they can
start a breeding program overnight from three
different genepools because the dogs are such fine specimens.
Oh if it were so simple.
Often overly enthusiastic newbies
in their over simplified thinking take this exact approach.
Unfortunately, it is the third generation
where the wheels come off. Why the third generation?
Well the first two liters were dynamite because they were both
F1 hybrid liters. But when the F1 hybrid offspring from
one linebred bitch are bred to F1 hybrid offspring of the other
linebred bitch things come apart.
In fact this "well laid plan" is a
sure receipt for breeding straight downhill.
So what is the answer? Wherein lies
the truth? It is not what you want to hear but here it
is: Years and years of line breeding by a committed ethical
Breeder - someone with a vision of perfection and the tenacity
to make difficult decisions. The only way to consistently
produce superior animals is to linebred. Period ... it’s that
Those who argue against linebreeding are inevitably those
who have never successfully bred animals themselves - most often
they are college professors. The same people who have bred
nothing more complicated than fruit flies or no more demanding
than lab rats are often the most vocal
about how others should breed
performance animals. These "know-nothings" advocate the notion
that out-crossing is in and of itself good because it produces
some thing they often refer to as "hybrid vigor".
To them, and to you, we pose this question: "If out-cross
breeding is the answer then why don't the owners of successful
herds of Holstein milk cows out-cross to the American Shorthorn
milk cow?" In theory this would produce super milk cows
by combining a milk cow that has the genes for high milk
production like the Holstein with one that has the genes for
high milk quality like the American Shorthorn.
Oh yes on both paper (the stuff of academia) and in theory this
should produce the best milk cows
But this is where the theory that reigns
supreme in the professor’s lab meets the reality of the
milk barn. Some of the most inbred animals on the face of the
earth are Holstein Cattle. The reality is that dairy farmers
know all too well is that they would go broke from the inferior
milk production of the resulting out-crossed animals. Crossing
to an animal with such poor milk production would be disastrous
fore them. And here in lies the rub
for all of us ...
Understand something and don’t let anyone sway you again.
Outcrossing does NOT produce “more” –
the genetic material remains the same. Nor
do the qualities of the subject animals
it produces multiply. Just as
linebreeding doesn’t damage genes - outcrossing doesn’t magnify
what’s in the genome. There is no magic in out crossing!
Note: So called "hybrid vigor" is never in and of itself the
answer to breeding better specimens. The quality of the specimen
used in any breeding is far more important than whether or not a
particular animal has a very low inbreeding coefficient or
whether the proposed breeding will result in a low inbreeding
And for those who continue to stubbornly
advocate outcrossing we ask you this final question:
"Even if by random chance the outcross
breeding in question would actually
produce a superior specimen would the animal in question be able
to reproduce itself? Would the greatness be passed on
to its get?" No.
The sad fact is that this superior
specimen would likely not be able to reproduce itself.
It will likely never throw a single specimen
as good as it is in its lifetime. This is because by
definition this “super specimen” is of the F1 generation. And
animals of this generation are rarely able to reproduce
themselves. So what has been accomplished by even a successful
outcross? Little or nothing other than
to put a single animal on the ground.
For fun I would like to invite
this no-nothing college professor to
the race track where for an afternoon he would have the
opportunity to bet on all the outcrosses and I would bet on all
the linebred race horses. I believe we call them Thoroughbreds
for a reason don’t we? Oh but I forgot he wouldn’t
be the betting kind would he? Not in his lifestyle
and not in his career. No, he would be the man of theory.
He would be a man who lives in the world of theory.
Not us my friend!
No, we both live in the world of
fact. Yes, we live in the world of bird hunting where what
separates the wheat from the chafe are immeasurable traits like
“heart” and “bird sense”. At Westwind GSPs we understand how
much is expected of these amazing athletes we call
German Shorthaired Pointers. You see we own
performance animals not lab rats.
Think about it. Those who advocate the outcrossing of
birddogs are effectively proposing that bird hunters entrust the
development of their performance dogs to the whims of random
chance. If you believe this is a wise course then you need to
locate another Breeder. May we suggest that you check the want
ad section of your local newspaper where you will find many
splendid examples of outcross breeding.
Successful linebreeding is a long and arduous task - one
that requires a lifetime's commitment to a particular line of
dogs. We have great respect for the few Breeders of German
Shorthairs who successfully developed and perpetuated their
particular line of GSPs in the past – fighting negative public
opinion all the way. Even if we don't have a single dog from
their particular line in our pedigrees we have studied their
breeding patterns and over the years have developed a deep
appreciation for their work.
It is from the legacy of Breeders who refused to settle, who
held to their standards when things didn’t go as planned that we
owe so much. It is from those Breeders who bred to the brother
of the champion because he produced better pups than the titled
dog that all of us enjoy a robust GSP gene pool today. To them
we all owe a huge debt of gratitude.
Although our breeding program remains a "hobby" our
commitment to the German Shorthaired Pointer remains strong. We
are looking forward to many more fine litters and many more
years of great hunting behind our beloved Westwind GSPs. Which
remains the single driving force behind our breeding program.