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From: [email protected] (Cindy Tittle Moore)
Subject: rec.pets.dogs: Breeding Your Dog FAQ
Summary: This introduces the reader to the difficulties of breeding dogs.
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Breeding Your Dog

Author

Cindy Tittle Moore, [email protected]
Copyright 1995.

Table of Contents

* Should I Breed My Dog?
+ I want to make some money!
+ My kids should see the wonders of birth and life!
+ I want another dog just like mine!
+ Every bitch should have a litter!
+ But my dog is registered!
+ So I should breed when...?
* Potential Hereditary Problems
+ Eyes
+ Hip and joints
+ Other things to check for
* Medical Checks before Breeding
* Temperament
* Pedigree Research
* Frequency of Breeding
* Care of the Pregnant or Nursing Bitch
* Caring for the Puppies
+ Prewhelping preparations
+ Postwhelping
+ Placing the puppies
* Considerations for Stud Dogs
* Genetics
* References

_________________________________________________________________

Should I Breed My Dog?

You may be wondering whether or not you should breed your dog. Here is
some information. The summary is that if you want to do it right, and
get healthy and happy puppies, it is very expensive and a lot of work.
Many people have written several treatises on this subject including
Ms Swedlow; this article compiles many similar points.

Remember that you are going to need a vet that is familiar with
whelping dogs. This will be your best resource, as well as any
long-time breeders that you know. Not all vets are knowlegeable about
whelping so be sure to ask around and especially look for
recommendations from local breeders that you may know.

I want to make some money!

Breeding, and doing it right, is an expensive undertaking. By the time
you've picked out a good bitch, waited for her to grow old enough
(minimum age: two years before breeding), picked out the best dog to
mate her with, gone through all the health checks she needs, ensured
that the dog you want to use also passes the same health checks,
you've invested a lot of time and effort. You still have to pay a stud
fee (or give a puppy back), you have potential extra expenses during
pregnancy, you have the time and expense of whelping (either you take
time off from work or something goes wrong and you have to take her in
to the vets). You need to keep the puppies for a minimum of 8 weeks
before sending them to their homes; you need to advertise and find
good homes for the puppies, you need to make sure they have had their
shots before going. You may have possible vet bills if the puppies
require extra attention. If some of the puppies die, or you have a
smaller than usual litter, you may not get as much money from the sale
of the puppies as you had though. There are even potential problems
later on with dissatified customers! You are better off consulting
with a financial wizard about investing the money you would otherwise
spend and lose on breeding!

Breeders frequently count themselves _lucky_ if they break even.

My kids should see the wonders of birth and life!

What if the whelping goes wrong and dead puppies are born? What if the
bitch dies? These are all very real risks that you are undertaking.
Much better alternatives include videotapes that are available. If
there are local 4-H clubs, those provide alternatives for children.

Or, you could contact your local shelter and see if there is a
pregnant bitch about to whelp or a litter of puppies that need to be
raised and socialized before being adopted out. This would allow you
to find out just what this could entail, while helping the shelters
rather than potentially contributing to the problem.

I want another dog just like mine!

If you want to breed your dog so as to get another dog like yours,
think about this for a moment. No matter how special your dog is to
you, a puppy out of it is not guaranteed to be just like or even
similar to your dog -- half its genes will be from another dog! You
will have to find another dog that also has the characteristics you
want in your puppy; that dog will have to be unneutered; and the owner
of that dog will have to be willing to breed her/his dog to yours. It
is much easier, often less expensive, and certainly less time
consuming to pick out an existing dog that you like from the shelter
or another breeder. Best yet, go back to the same breeder of your dog,
if possible, and pick another puppy out of similar lines.

Every bitch should have a litter!

This is flat out wrong. Bitches are not improved by having puppies.
They may undergo _temporary_ temperament changes, but once the puppies
are gone, she'll be back to her old self. Nor is it somehow good for
her physically. In fact, you will put her at risk of mammary cancer
and pyometra. There is absolutely nothing wrong with spaying a bitch
without her having a litter.

But my dog is registered!

Well, yes, but that doesn't _mean_ a whole lot. A registered dog, be
it AKC, UKC, CKC, etc., simply means that it's parents (and their
parents) are also registered with the same registry. This confers no
merit in of itself, it simply means that the dog's parentage is known.

Most registries do not make any assertions of quality in the dogs they
register (except for some limited breed-only registrations, but these
are uncommon). They do not restrict the breeding of their dogs and
hence there is no guarantee that a registered dog is a good specimen
of its breed.

The AKC has just started a "limited registration" program whereby
puppies out of such dogs are ineligible for registration. It remains
to be seen what the overall impact on AKC dog breeds will be. Other
registries have used similar programs with good results.

So I should breed when...?

The _only_ reason you should be breeding is that you honestly feel
that you are improving your breed by doing so. There are far too many
dogs in the country to breed without good reason. A dog in a breeding
program must be one whose genetic history you or its breeder is
intimately familiar with. Such a dog must represent the best efforts
of its breeder at that point. Such a dog must have good points to
contribute, whether that is in good conformation, good performance or
whatever. Such a dog must have some evidence of external evaluation.
That is, others besides the breeder or the owner must also think that
the dog is a good representive of its breed. That usually translates
into titles, whether for conformation, obedience, field, herding, or
whatever is appropriate for that breed. Such a dog must be tested as
it matures for any problems that tend to appear in its breed, whether
that is hip dysplasia, patellar luxation, von Willebrand's, cataracts,
PRA, fanconi syndrome, subaortic stenosis, etc.
_________________________________________________________________

Potential Hereditary Problems

Every breed has a different set of potential problems for it. I have
listed common ones below, but this is not to say that all dogs must be
checked for everything listed. You need to do research in your breed
to find out what the common problems are. You will also need to
research the particular bloodlines you are using to see if they are
prone to any additional problems you want to know about and screen for
as well.

Eyes

Most breeds require eye checks of some sort, for a variety of
problems. These include, but are not limited to problems such as
* Progressive Retinal Atrophy (PRA). This disease eventually causes
total blindness. In some breeds the onset is quick, before the dog
is two or three. In others, the onset is much later, when the dog
is four to eight years old (and may have already been bred). Irish
Setters have a test available that can detect carriers and
affected dogs; other breeds do not have this recourse. It appears
to be a simple autosonomal recessive, but the late onset
complicates breeding programs. If a dog is affected, then both
parents are either carriers or also affected.
* Retinal Dysplasia. Causes eventual blindness. This is believed to
be hereditary. Some dogs can be detected with this condition in
puppy hood, but carriers cannot be identified until they produce
such puppies.
* Collie Eye Anomaly (CEA). This affects the collie breeds (bearded,
border, rough, smooth) as well as some closely related ones. This
condition also causes eventual blindness and is inherited.
* Cataracts. There are many forms and causes for cataracts, but some
forms, such as juvenile cataracts, are inherited and such dogs
should not be bred.
* Entropion, Ectropion: These are conditions in which the eyelids
turn in or out, causing various problems and often pain for the
dog.

The Canine Eye Registry Foundation (CERF) in the USA registers dogs
that are found to be clear of eye problems by a board certified (AVCO)
veterinarian. Dogs need to be cleared yearly as there are some types
of eye problems that show up later in life.

Hip and joints

There are a variety of joint problems found in most breeds. Toy breeds
can have joint problems too; just because your breed is smaller
doesn't mean you can figure you are free of hip dysplasia and be done
with it. There are several problems that specifically affect smaller
dogs!
* Hip dysplasia is probably the best known problem. This is a
malformation or deterioration of the hip joint, so that the socket
it sits in is too shallow to secure the head of the femur. As the
condition progresses, arthritic changes begin to destroy the
protective cartilage and the dog may experience severe pain if the
condition is bad enough. Some dogs are asymptomatic, but still
should not be bred. This condition primarily affects the
medium-to-large breeds, but smaller breeds have been known to be
affected, for example Cocker Spaniels and Shetland Sheepdogs can
have this problem. To make sure your dog is free of hip dysplasia,
you need to have the hips radiographed and then obtain an expert
analysis of the xrays. Your vet isn't necessarily the one to do
this! In the US, you would mail the xrays to the Orthopedic
Foundation of Animals and wait several weeks for their evaluation.
In Canada, Europe and Britain, there are equivalent programs, but
all differ in the type of certification and age at which they will
certify; some organizations certify after one year of age, others
certify after two years of age.
* Osteochondrosis Dessicans (OCD) is an elbow joint problem. A bone
spur or a flake wears away at the joint which becomes stiff and
painful. Xray evaluations of these joints are also needed. Many
breeds that are prone to hip dysplasia may also have OCD.
* Patellar Luxation is a problem affecting the kneecaps. Smaller
dogs are more prone to this problem than larger ones are. The
kneecap will slide out of place and lock the leg straight.
Diagnosis is fairly straightforward and surgery can correct the
problem, but no dog with patellar luxation should be bred as this
is also an hereditary condition.

There are a few other types of problems, affecting other joints like
the hocks, or affecting the spine, that you should be aware of in some
breeds. This is only an overview to give you an idea of what kinds of
problems are out there. Remember that joint problems, even if not
hereditary, may make it problematic for a bitch to be bred. Pregnancy
is hard on the joints and on the body in general and if she isn't in
the best of physical health, it is much kinder not to breed her.

Other things to check for

* In some breeds, deafness is a potential problem. Puppies at risk
should be BAER tested and any that fail should be neutered.
* _Heart conditions_ in many breeds must be checked for. Subaortic
stenosis (SAS), other malformations of the heart or valves.
* Hemophilia type of problems, e.g., von Willebrand's disease and
others.
* Malabsorptive syndromes, digestive problems.
* Epilepsy.
* Allergies.
* Incorrect temperament for breed.

Finally, remember that not only the potential dam _but also the sire_
must be checked for all the things appropriate for their breed and
particular bloodlines.
_________________________________________________________________

Medical Checks before Breeding

You must make sure the bitch and the stud both are free from
brucellosis before breeding them. Brucellosis causes eventual
sterility in both sexes (sometimes non-obviously) and can cause a
litter of puppies to be aborted or die shortly after birth. In
addition, brucellosis is on occasion transmissible to humans via the
urine or feces of an affected dog. Between dogs, it is most commonly
passed in sexual intercourse, although an entire kennel can be
infected through contact with secretions.

The sire should be in excellent general health. The dam _must_ be in
good health, to withstand the stresses and rigors of a pregnancy. They
must both be up to date on their vaccinations.
_________________________________________________________________

Temperament

Never breed any animal that has temperament problems. In particular,
this has been the cause of the degeneration of many breed's general
temperament: Doberman Pinschers, Rottweilers, and so on. If your
animal is untrustworthy around people, overly aggressive to people,
excitable, or is a fear-biter, do not breed it. If it is shy or
submissive, don't breed it. Look for happy, confident and obedient
animals, and consider carefully the particular temperament
requirements for your dog's breed.

There are a variety of tests to indicate a dog's temperament. Many of
the working breeds have a temperament test (for example, the
Doberman's WAC test) for their breed. AKC has a Canine Good Citizen
test (open to all dogs) that gives some indication of the dog's
temperament (and, yes, training). Therapy Dogs International and other
Therapy Dog clubs have temperament testing that does try to separate
out actual temperament from training. Obedience titles can be (but are
not necessarily) an indication of good temperament.
_________________________________________________________________

Pedigree Research

You must carefully consider each dog's pedigree for compatibility. Try
to select strengths to offset weaknesses. Do not allow your bitch to
be bred to an unsuitable dog, and conversely, be picky about the
bitches you allow your dog to breed. This phase alone requires
considerable research to find a suitable candidate, and you should
definitely work closely with a knowledgeable person, ideally the
breeder of your dog. Simply because two dogs "look good" or even *are*
good does not mean that they necessarily complement each other:
suppose they are both carriers for the same disease? Suppose they both
have a tendency to overbites or other disqualifying faults?

Be honest with yourself. If your dog is not a good representation of
its breed, do not let it reproduce. It is much easier to improve a few
faults than to try and get excellent pups with a mediocre dog. Check
the breed standard for your dog and ask a knowledgeable person for
their evaluation of your dog.

We'll return the the importance of scrutinizing a pedigree in the
genetics section below.
_________________________________________________________________

Frequency of Breeding

Ideally, a bitch should only be bred every other year and she should
not be bred much before two years of age. The season closest to the
second birthday is a good one to start with; certainly no earlier than
this. In some breeds, you may need to wait one more season before
beginning. By this time, she is better prepared mentally for having
puppies than she would have been with her first few seasons. Her
physical growth is complete and pregnancy at this point won't endanger
her health, provided that she is healthy to begin with.

In breeds with Hip Dysplasia, many people wait until after two years
of age so that the parents can be certified; however if you have sent
in xrays to OFA for preliminary evaluation and they came back as fine,
many breeders consider it safe enough to then breed on the season
closest to the second year, which can wind up being before the bitch
is actually old enough to be certified. (And when the bitch is old
enough, she is, of course, duly certified.) But the preliminary xrays
_must_ be examined by OFA, not by a local veterinarian. There are many
dysplastic dogs out there that had vets look at their xrays and
pronounce them "wonderful."

It's important, however, to keep the frequency of breeding low. Even
at maximum, you want to allow at least one unbred season between
breedings. This allows your bitch to rest and regain her strength. A
bitch that whelps too often will produce weaker puppies more likely to
die, and the repeated pregnancies are pretty rough on her, too.

For dogs, they should definitely have all their certifications
necessary. For many breeds this means that they should be over two
years old. Since a dog can be bred at any time, unlike bitches,
waiting for two years is not a problem, whereas a bitch often has a
season just before two years of age and then has to wait until 2.5 or
three which sometimes presents problems in trying to time her litters.
But this does not apply to a stud dog, so he should definitely have
all of his checks and certifications before being bred. Frequency is
not generally a problem although some dogs have problems with sperm
production if they breed once a day for several days. They need
top-quality feeding and care if they are going to be bred often.
_________________________________________________________________

Care of the Pregnant or Nursing Bitch

You should make sure the bitch is up-to-date on all her vaccinations,
medications, and shots before she is bred. She will require
supplementary food during the last three weeks or so of pregnancy. In
general, puppy food is formulated both for puppies and pregnant or
nursing bitches.

She should be under the care of a vet for any related problems. Dogs
can have miscarriages. Illnesses, diseases, or infestations that the
bitch picks up during her pregnancy can affect the puppies.
Difficulties during whelping are entirely possible, and the rule for
some breeds. You must be prepared to get her to the vet quickly in an
emergency.

There are instances of "mummy puppies" where you have a puppy whose
development went awry, but it was not aborted. Instead, it dries and
shrivels up, and when born, looks like a mummified puppy, blackened
and ready to rot. Overbreeding and inadequate care are usually the
causes. It is quite likely that the dam will come down with an
infected uterus after such a puppy. "Water puppies" are another type
of problem in which the dead puppy appears to have never properly
developed a skeleton and appears to be full of gelatin. This seems to
be linked to a viral exposure.

Other congenital (but not genetic) defects can include: no anus, cleft
palates and hare lips. These conditions require corrective surgery or
the puppy will die.

While the bitch is nursing the puppies, she will require about three
times the amount of food she normally eats! It is also common for
nursing mothers to go out of coat at this time.
_________________________________________________________________

Caring for the Puppies

Prewhelping preparations

You should have a sturdy, clean, proper sized whelping box for the
litter. It MUST include a "pig rail" around the edge to prevent the
bitch from laying on or smashing her pups. It should be big enought to
allow the bitch to turn around but small enough to prevent the pups
from being "lost" in the unused portions. About six inches longer than
she is, fore and aft, when laying prone (as in suckling her puppies)
and about a foot on either side length wise.

To get the whelping box ready for your bitch, get a sheet of plastic,
such as you would use for painting a ceiling to protect the floor. Cut
it up into several pieces the size of the whelping box. Put one piece
of plastic down, several layers of newspaper, another piece of
plastic, more layers of newspaper and so on for four or five layers.
Then when your bitch is whelping puppies, you can roll off a layer
when it gets messy -- and it will! -- and throw it away to instantly
clean the whelping box.

Postwhelping

After the puppies are born, there are many strategies for lining the
whelping box. Some people continue to use newspapers, but puppies get
pretty dirty from both newspaper print and feces. Other people have
had success with synthetic materials on top of absorbent materials:
the synthetic material provides secure footing, but the urine and
other liquids pass through it to leave it dry. Other people use pine
shavings (about six inches deep). You will do a lot of laundering to
keep things clean no matter what you use. You will also have to clean
the feces out of the whelping box after your bitch decides that's no
longer her job.

Newborn puppies MUST be kept warm. The temperature in the whelping box
at birth should be 90 F. The temperature can then be decreased 2
degrees every other day. NEVER FEED A CHILLED PUPPY!!! If a puppy
becomes chilled it will cry continually and it will tuck its tail
between its little legs. A healthy, happy, litter will "purr" like a
swarm of bees and when feeding their tails will be straight out from
their bodies. Warm any chilled puppy by putting the puppy under your
shirt and under your armpit. The best method of warming a puppy is to
use a special whelping box heating pad with a towel over it to prevent
soiling the pad. Make sure the temerature does not go too high.
Heating lamps are ok but puppies can become dehydrated. If the litter
clumps together and cries, they are too cold; if they separate and try
to hide under shade, they are too hot.

Large litters will require supplemental feedings if you want all the
puppies to survive. Your bitch may not be able to care for a very
large litter. You will need to get the pups rotating on shifts. For
the first two weeks you may have to supplement as much as every four
hours. Use a good prepared milk-supplement especially formulated for
puppies. If you get in a bind you can use a goat-milk reciepe avilable
in most books about breeding and whelping pups. You may have to tube
feed those pups that will not suckle from a bottle!

Are you going to remove the dewclaws or dock a tail? This must be done
by 3 days old at the latest! Any later will not heal as nicely or
quickly!

If you have a purebred litter, you must record the date of birth and
all of the pups (including the dead ones) in your record book. Then
you will need to fill out and send in your litter registration form.
You want to do this as soon as possible, since many registries can
take up to 6 weeks to return the forms for individual registration to
you (which you will want to give to your puppy buyers later).

You will have to keep the whelping box clean. For the first two weeks
the bitch will keep the pups pretty clean, but the bedding should be
changed twice a day at minimum. Starting week three, the pups start to
eliminate some on their own.. then you will need to clean much more
often!

At four weeks, the pups usually become very active and it this time
may require a larger area then the welping box...you will need a large
ex-pen or some way of confining them safely. You do have a place to
keep them that they are safe in and can't destroy? Puppies at this
stage can devastate a room or garage in hours.

At week five you will probably want to introduce the pups to weaning
food. Usually you will have to mush up the dry puppy food for the pups
to be able to eat it. Use warm water and let the food stand in a bowl
for about 2 hours.

At week six you should vaccination and worm the pups, and have them
checked for heartmurmers, hernias, males for testicles (yes you should
be able to feel them at 6 weeks!), deafness, and eye problems.

You should be socializing now too... And are you going to do any puppy
testing for temperaments? At seven weeks you should be calling up
those poeple with deposits on your pups and getting your paper work
all sorted out. Are your spay/neuter contracts ready? How about
pictures of the pups for your clients?

And this is just if everything goes perfectly! What happens if one of
the pups has a heart murmer, or a hernia? What about a deaf puppy?
What if your whole litter gets parvo or distemper? What happens if one
of the pups is affected with "swimmer-puppy" syndrome? What about
fading-puppy syndrome? What happens if your bitch gets an infection or
mastitis? What if she dies?

Placing the puppies

After the puppies are born, if not before, you must consider placing
your puppies. Time and time again, people breed a litter because
friends and family want one of their dog's puppies -- and then none of
them will take one.

At six weeks is when even seasoned breeders wonder why they do this. A
healthy active litter of six will run you ragged at this age. They are
so curious, they want to explore everywhere, and they are at the prime
age for socialization and exposure to many things that you, as a
responsible breeder, want to give them a head start on.

At eight weeks, you may begin placing those pups that are ready to go
to their new homes. Insecure pups may need more time, how are those
puppy tests coming? You can't place puppies earlier than 7.5 weeks or
so (no matter how much you may want to).

Are you prepared to do some legwork to find GOOD homes for them, not
just hand them off to the first person who comes by? You are aware
that you won't always be able to sell all of your puppies locally,
aren't you? What assurances do you have that the puppies will not wind
up filling animal shelters, facing death because their parents were
thoughtlessly bred? Suppose you wind up keeping more of the litter
than you intended to? Suppose some of your puppies are returned? Can
you keep the extra puppies?
_________________________________________________________________

Considerations for Stud Dogs

First, remember that it is extremely difficult to come up with a top
quality stud dog that people want to use. After all, they will look
around and pick out the best male they can find. So your dog has to be
pretty impressive to be noticed in the competition.

Your male should be in top condition. He should be certified clear of
joint problems (and in many cases that means he has to be at least two
years old). His eyes should be checked annually. He should be clear of
any abnormalities common to his breed. No heart problems, no seizures,
no thyroid problems, etc. He should be clear of brucellosis. His
temperament should be good, and appropriate for his breed. If you have
such a dog, you will need to get your dog well known. This generally
involves showing your dog (in show, field, or obedience) and doing
other work with him. An unproven dog (that has no previous puppies or
only puppies too young to evaluate) will command a much lower stud dog
fee than a proven dog (with a record of puppies to examine).

You must be prepared to board the bitch. The common procedure is for
the bitch to be shipped out to stud, so you will need facilities to
board bitches in heat. These facilities should be adequate for up to a
week of boarding and to prevent any mismating. You might wind up with
more than one bitch at a time -- can you board them all safely?

You must monitor the mating and be ready to intervene if necessary.
Some breeds require intervention (such as Basset Hounds). Not all dogs
or bitches understand what to do, especially if it is the first time
for one or the other. It can be disastrous if two dogs are left alone
to mate. Additionally, if the mating doesn't take, are you prepared to
go through the whole thing again the next time the bitch comes into
season? Typical contracts call for free repeat breeding in the case
two or less puppies occur or the breeding doesn't take.

You need to be able to evalate the bitch's pedigree for compatibility
with your dog's. Any good points or bad points of the litter are
(rightly or not) attributed to the sire, so your dog's reputation is
at stake with each litter he sires. You should be reasonably confident
that the proposed breeding will result in good puppies.

If the owner of the bitch is a novice, are you prepared to assist with
advice on whelping and puppy care? These people will expect you to
have the answers. Sometimes entire litters of puppies are dumped on
the stud dog owner when the bitch's owners can no longer cope with
them because they didn't realize what a responsibility caring for a
litter involved. Are you ready to take care of and place your dog's
offspring if this should happen to you?

Are you prepared to deal with cases where you are certain your dog is
not the sire of the puppies but the bitch's owner insists that he is?
Or if the owner of the bitch insists that you must have allowed a
mismating to occur when she was boarded with you? Disputes of this
sort can become very ugly very quickly.
_________________________________________________________________

Genetics

_If a purebred dog of breed X mated with a purebred dog of breed Y,
both meeting health standards for their breed, is there a better
chance the offspring would be healthier than a same breed mating
because the gene pool is larger?_

In terms of health alone the first answer would be that in breeding
two healthy dogs it shouldn't matter if they're the same of
different breeds, you're apt to get healthy pups. But this doesn't
take into account the question of recessives. Suppose you breed two
dogs of different breeds that both have the same incidence of a
recessive health problem. The pups would have the same odds of
having that health problem as purebred pups of either breed. On the
other hand, suppose the two dogs were of breeds that have no
recessive health problems in common. This would reduce or eliminate
the odds of the puppies of having the health problems of either
breed. This is the classic explanation for the theory of first
generation hybrid vigor. The resulting pups should not be bred
though, since they'd have a good chance of having the recessives
from BOTH breeds, so the grandpups would be inclined to be worse
off than the purebred offspring of their grandparents. An excellent
set of articles dealing with "hybrid vigor" can be found in
_DogWorld_, Jan 1997 by George Padgett DVM. Another _very_
important point to keep in mind is that when a purebred carrying a
genetic defect is crossed with another breed or mixed breed, the
"bad" genes do NOT "go away" even though they may not be expressed
in the offspring. If crossed with another dog carrying the same
defect, the offspring of that breeding _will_ demonstrate the
defect.

_Purebred dogs have all these diseases, though! It seems that you
never hear about mixed breed dogs with problems._

Responsible breeders try to identify genetic diseases their dogs
might be carrying and to eliminate them by careful breeding. It is
ironic, though not surprising, that their efforts to identify and
weed out genetic problems have lead some to cry "look at all the
genetic diseases purebred dogs have!" A moment's careful thought
will lead you to the conclusion that mixed breeds carry the _same_
harmful genes (their parents, or their parents' parents, _were_
purebreds, after all). The differences are
* with some recessive disorders (though not _all_ genetic defects)
the disease is less likely to be _expressed_ (though it can still
be inherited by offspring)
* you have lesser likelihood of ever identifying or eliminating any
harmful genes your mixed breed may be carrying

Also, if you stop and think about it, many mixed breeds are simply
not tested for most problems. When they get older and limp, it's
just considered old age, although it could well be hip dysplasia.
When they get older and start to go blind, it could be PRA, but the
owners are unlikely to test for this. It's not that owners of mixed
breeds are bad, by any means, but they are not looking for possible
inheritable problems, either.

_When you breed two different breeds together, what kind of variation
can you expect?_

Pfaffenberger's book has some interesting data on this. He did some
experiments with four different breeds. They were dogs of
approximately the same size, but very different physical appearance
AND behavior. The results he saw in the first and in subsequent
mixed generations are pretty interesting.

Let's look at a common crossbreeding: "cockapoos" (which are _not_
purebred dogs, nor registered with any registry). These are crosses
between Cocker Spaniels and Minature or Toy Poodles. The dogs
actually vary quite a bit, some being more poodle like than others,
and some being more cocker like than others. However, they are
generally all a small sized, buff colored shaggy dog. If you breed
two cockapoos together (not generally done), you get an even wider
variation of dogs -- some look like Minature Poodles, others like
Cocker Spaniels. The reason for this is the recessive genes hidden
in the first cross that came out in the second generation. This is
actually a visual example of why "hybrid vigor" doesn't hold.

_What is outcrossing?_

Outcrossing is where the sire and dam are totally unrelated,
preferably for three or four generations. The true form of an
outcross is between two entirely different breeds because in
reality the members of most registered breeds come from a common
ancestor (althought it may be many, many generations back). It is
very rare for outcrossed puppies to be uniform in appearance.
Usually there are a very large ranges of sizes, coats, colors,
markings, and other distinctive characteristics. Outcrossed litters
are generally heterozygous, and do not reliably reproduce
themselves, so even the nicest puppy in the litter may not later
produce the best puppies.

Outcrossing is generally used to introduce something new to a line
-- a better head, better colors, better front, etc. Usually the
puppies retained from these breedings are bred back into the
breeder's original line to standardize them back into the line's
general characteristics and reproducibility -- with the one desired
characteristic. The tricky part is that other characteristics may
come along for the ride!

If you are dedicated enough, you can eventually continue breeding
by outcrossing alone (but don't expect instant or quick results).
You should pick dogs that complement eachother well and are similar
in general appearance. This is a long hard road to eventually
developing a line. Through outcrossing, many health problems can
quickly be eliminated (or just as quickly added into your
breeding), but usually you do sacrifice some show quality and
producibility.

You have to remember that dogs that appear totally healthy may be
carriers of genetic problems. To find this out, test mating is done
to a dog that is affected with the genetic problem (resulting
usually in puppies that are both affected and non-affected
carriers) or by inbreeding to a related dog that also doesn't show
the signs of being affected (usually littermates are used) this
will usually result in some puppies free of the problem, some
puppies as carriers, and some puppies affected if both dogs carry
the problem gene (this is not as accurate as breeding to an
affected dog, but you are less likely to have to put all the
puppies down).

There are variations on outcrossing. A "true" outcross could be a
dog that has totally unrelated dogs bred together throughout the
pedigree. This is very rare. On the other hand, "linecrossing" is a
form of outcrossing where dogs from unrelated lines are bred to
produce a new line. The sire and dam are usually very linebred from
their prospective lines and the resulting puppies are varied in
appreance, some looking like the sire's line and some looking like
the dam's line and some looking like mixtures of both lines.

_How about line breeding?_

Line breeding is when the sire and the dam are distantly related:
e.g., grandsire to granddaughter, granddam to grandson, second
cousins, half cousins, uncle to niece, aunt to nephew..... The
general strategy is that there is a common ancestor that is being
doubled up on both sides. So the desired dog appears several times
in the pedigree.

This is probably the most common strategy in breeding purebred dogs
(and in developing new breeds, for that matter). Though this
method, new genes are slowly introduced and unwanted genes are
slowly replaced. The actual rate varies by how strongly you line
breed. It sacrifices little overall quality in terms of show
quality. Usually the puppies are rather close in general
conformation. The only problem with this method is that it often
takes several generations to get poor genes out, (or adding desired
genes in) resulting in many puppies that have the same genetic
problems (or virtues) that their parents have. And then because
some breeders are more interested in winning, they do not place the
affected puppies on spay/neuter contracts. This is both a blessing
and a curse for the breed. If the breeder is very careful, affected
pups can be used wisely to prevent loss of quality, but still
remove the affected genes by only breeding the affected pups to
known non-carrier relatives. This way the breeder can again try to
"edit out" the bad genes. It takes longer this way but less show
quality is lost in the process. This process results in dogs that
will often reproduce their same level of quality. This is refered
to as reaching homozygous litters (more genes of the same kind
apparent in the puppies).

Inbreeding and linebreeding really differ only in degree.
Linebreeding is less likely to cause harm than inbreeding.
Inbreeding is not for novices. Knowledge of genetics and the breed
is required for success. For good results it must be well-planned
and breeders must be ready for whatever problems it presents.

_And inbreeding?_

Inbreeding is where the sire and the dam are closely related:
mother to son, father to daughter, sister to brother, half sister
to half brother, cousin to cousin. People disgree about the exact
point at which inbreeding becomes linebreeding. Inbreeding is the
quickest way to find out what poor genes are in the line and what
dominant characteristics are in the line.

Although many people are disgusted with the idea of this family
incest, it is an extremely useful tool for diagnosing what genes
are present. If the genes for bad eyes are present, but hidden or
resessive, this will bring them out to their full extent. If there
isn't any bad genes, then the puppies will be of very close
uniformity and very able to reproduce themselves (theroretically).
This is a homozygous breeding. The resulting puppies will have a
lot of genetic material that is the same as their parents and
grandparents and will be close genetically to each other.

Inbreeding doesn't introduce new genes and does not eliminate bad
genes that the line already has. It only shifts them around like a
rubix cube. This often results in litters with high show potential,
if the quality was high to begin with. It shows you what recessives
you have lurking in the dogs' backgrounds -- _both_ good and bad.
But there are drawbacks. Besides the possibility of bad recessives,
inbreeding exclusively will eventually lead to infertility. It's
like a xerox machine. After so many copies, you have to renew the
ink. The same with dogs, you have to introduce new genes. No
reputable breeder will use inbreeding exclusively, and many
breeders simply never use it. Usually, you will only find: very
experienced breeders, ignorant breeders, and puppy mills making use
of this technique.

Inbreeding increases the chance that a gene obtained from the sire
will match one obtained from the dam, both stemming from the common
ancestor(s) on which the individual was inbred. Thus, inbreeding
tends to make animals homozygous rather than heterozygous. The
inbreeding coefficient measures the resulting increase in
homozygousity. All breeds have a given degree of homozygosity the
mating of two dogs from the same breed would not produce a
recognizable specimen of the breed!

Inbreeding increases homozygosity and decrease heterozygosity. So
it can duplicate both desirable and harmful alleles, both of which
can be unsuspected in the line, and may appear. Inbreeding does NOT
create anomalies, it brings present anomalies to the surface. Even
when the anomalies are present, inbreeding might not reveal them.
However, once revealed, then the breeder can do something about
them in the next generations of breeding.

An increase in harmful recessives is undesirable but it is not a
major drawback if they are identified early. The effect of
inbreeding on major polygenic traits is greater. Generally, traits
that are highly inherited (ie largely additively controlled) are
not adversely affected by inbreeding but, traits under non-additive
control, especially those tied to dominance and thus not of high
heritability, are often markedly harmed by inbreeding.

_OK, how do pedigrees figure into this?_

Remember that it is difficult to spot unaffected carriers. When an
affected dog shows up, its pedigree is often examined for likely
carriers. For example, PRA is a common problem in many breeds.
There are dogs that come down with PRA that have a certain ancestor
in common. That ancestor may then be considered a possible carrier
and line breeding on him is avoided. This is a simplistic picture,
obviously, since it's possible for an unaffected non-carrier of PRA
to come from an unaffected carrier that came from an affected dog
(therefore the affected dog is in the unaffected dog's pedigree).
If a general blood test is ever developed that shows the presence
of the recessive in an unaffected dog, then much more accurate
breedings may be done; currently this is only possible for Irish
Setters.

There is rarely only a single problem a breeder is trying to screen
for. Suppose a suspected carrier of PRA is known for producing
excellent hips. A breeder might therefore introduce that bloodline
into theirs for the hips, and be willing to have the possibility of
PRA show up in the line. In screening out one problem you might
have to accept the possibility of another appearing.

Examining the pedigrees also lets you know what percent of ancestry
the dogs share (since the relationships are often much more complex
than simply cousins or aunt/uncle, the degree of common ancestry is
often given as a percentage instead) and decide whether or not it's
acceptable given your current goals.

_What are like-to-like matings and compensatory matings?_

Like to like mating implies the best to the best and the worst to
the worst where the worst is not used at all. For most breeders,
like to like matings are between dogs which resemble each other
greatly and so similar type dogs are bred. These dogs may or may
not be closely related.

The pups resemble their parents because of the genes in common with
them. If those parents resembled each other their progeny would be
even more like their parents. This tends to make the population
look more uniform, however there is little increase in prepotency
from this technique.

Compensatory Mating: This unlike to unlike mating is used by
breeders to correct for a defect in an animal by mating it to
another animal that might correct for the defect. The system is
basically simple but the breeder must identify faults and virtues
and it requires breed knowledge. The pedigrees of both dogs should
be examined carfully to try to identify the ways in which the dogs
differ and what the expected outcomes could be. A correct dog and
not one who errs in the opposite direction is required. That is, if
you want to improve structure, look for a dog with correct
structure and not an overbuilt dog. This technique often results in
only one or two pups with the combination desired.

_But this is all very vague and complicated!_

Yes, it is. There are no easy answers, and there are different
things to consider in every breed. This uncertainty with respect to
genetic inheritance is exactly the reason that breeding is so
difficult to do right. It helps immensely to have a "mentor",
someone who is familiar not only with the breeds, but the lines
your dog belongs to -- advice from such a knowledgeable person is
often extremely valuable.

If we knew everything about genetics, we wouldn't _have_ problems
with our dogs any more. We'd eliminate Hip Dysplasia, PRA, heart
problems, thyroid problems, seizures, etc. within a few generations
if we knew everything. Unfortunately it's an art that few people
are actually very good at.

_________________________________________________________________

References

"So you want to use your Dog At Stud?" From the Literary Spot, the
newsletter of the Central MD Dalmation Club 12/89 via Retriever
Believer, the newsletter of the Labrador Retriever Club of Southern
California 8/91.

Tucker, Kathy. "Why are you Breeding?", printed in various
newsletters.

Whitney, Leon E (DVM). _How to Breed Dogs_ 384 pg. Many case studies
on breeds, breed crosses for dominance studies, Myths and fallacies
about breeding dogs, inheritance of traits (such as temperament,
health, intelligence, and abilities).

Wilcox, Bonnie (DVM). "Things to Think about Before Breeding Your
Dog." DVM, printed in various newsletters.

Willis, Malcolm B. _Practical Genetics for Dog Breeders_. Howell,
1992. 228 pgs with appendix for calculations -- several graphs,
charts, and pictures.

Willis, Malcolm B. _Genetics of the Dog_. 417 pgs with breed specific
information on many breeds -- plus several charts and graphs.
_________________________________________________________________

Breeding Your Dog FAQ
Cindy Tittle Moore, [email protected]

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