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Practical Genetics in Dog - breeding

© Author : Malcolm B. Willis

1^st edition 1992

Ó Kynos-Verlag Mürlenbach 
for Germany to order therefrom directly
title: Genetik der Hundezucht

the original version is available London (Ó H.F.&G. Witherby LTD )

brief summary - out from that book:

Habits depending on gender destined to the genes which come from both - male and female -, e.g. Cryptorchism, only visible at the males - but can be carried also by the female.

There are other habits depending or controlled by gender .....some genetic defects are more often shown at the one gender, e.g. HD = male and female are concerned but females are a bit more concerned (similar to humans med. Spina bifida, a disease of the spine, is more often found in girls than boys).

Important for the breeder are habits conc. Character and power - vitality. Also construction of body and proportions should be considered .....not too much or to less of sthg. - well balanced is always better.

Some of the exterieur habits (such as size e.g.) are also related once to gender and besides that to nutrition and genetics as well.

Height (at withers) has an inheritability of 40 - 65 % = medium to high inheritable.

Fertility ¨ 10 - 15 % = very low inheritable

but unless in a high degree of genetic influence.

The higher the percentage of inheritability the better the chances to point out what we might get from a combination.

Inheritability defines the relation of the parents qualities given to their descendents.

From the genetical point of view

low inheritable = up to 20% or less

medium = 30 - 50%

high 50 and more %

Relative Evaluation in percent - what to read out of pedigrees - see book .....

Just one Example : Inheritability for HD in the average 40%

But look at the parentdogs values and get about 63% out of it

Each evaluation and measurement of the breeding animal itself
is the best indicator for the breeding potential !

Following bloodlines is a very important thing as a conscientious breeding program seeks to maintain and possibly to improve the quality of the breed. A successful breeder is one who knows the virtues and faults of all the dogs in a pedrigree for 4 generations.

Knowledge of this sort does not come quickly or easily. It requires to learn not only everything about the breed, but esp. about the bloodlines the breeding stock is chosen from. Best is to see the production of generations, the winners and littermates as well the retired dogs and littermates. A "vital and healthy" 2nd or 3rd generation is the best promotion for a breeder resp. puppies out from a kennel.

Linebreeding = selective inbreeding - is often done to enforce the positives of inheritable habits known in this line - but by the same way the latent/recessive inheritable faults are enforced too ! !

Therefore linebreeeding is only advisable if both parents bloodlines are known very clearly - for their goods and their bads ! ! ! !

Remember : none of the parent dogs is more import, both are the same - 50 % of each parentdog

Some rumor like ¨the male brings the exterieur and the female brings the character ¨is pure nonsense and there is no serious research work done on this ! For the single dog - puppy conc. Inheritance both parent dogs are of the same value in their importance and influence.

The influence of the male for the breed in general of course is much higher - due to the fact that a male is able to sire many litters = he has always more descendents than the female.

Habits by learning are always the result of the environment of the puppies - don’t mix that up with the inherited habits ! ! !

Character / Temperament -not depending on the breed- a l l animals meant for breeding have to be very reliable. 
Nervous animals are always a latent danger (so-called "fear - biter").

Never breed with nervous animals !

Exception of that rule .....if the Nervousness is a habit by learning (most due to only one or some spec. situations).

The same - and even more - is valid for aggressive animals - never, never do any breeding with aggressive animals !

To be reliable the dog has to have a stabile character - can well be dominant - one has to distinguish between dominance  (alpha-dog) and aggression.

A stud dog needs to have a good character !

Newcomers in dog-keeping should not decide for a alpha-dog (because that needs experience to be handled) - the breeder will be able and find out the difference in character and temperament of the puppies due to experience and tests.

Never, never force the instinct for fighting in a dog because it always means to enforce the unwanted habits. 
There is no need and no right therefore - it’s a crime against the animal itself and the humans.

Each dog held as a "member of the family" will protect the family if necessary - because "protecting the pack" is a very natural instinctive habit.

A male - no matter how many prices he won, can be the greatest champion - should not be used for stud if the character is not good  - and no male - unless how many advantages he may have - is suitable for e v e r y female !

Tableau 10 in the book: Reasons for Aggression of Dogs

Bone- and skeletal diseases are complex in the manner of inheritability and highly influenced by conditions of environment such as nutrition and others. Too many breeders feed to obsessive supplements, most of all Calcium and by doing this the balance of the nutrition is disturbed.

A well balanced nutrition can of course not heal any diseases but surely avoid some of them and it can even be helpful if there are already known diseases that they don’t become that serious with a well balanced diet.

Tab. 14 Diseases conc. Heart, Blood and Circulation

Tab. 15 Defects orthopedical

Tab. 17 several defects

Hip Dysplasia - HD = sep. chapter in the book.

The HD was first mentioned in connection with dog breeding at 1935.

The hip joint means the femur and the acetabulum. The acetabulum is a part of the hipbone. Optimal hips = the Femur is formed like a tennis ball which fits exactly in a cup (Acetab.). If the cup is too flat, the femur slider’s and it is not tight. HD appears, if it is not tight, no optimal fit-in but sliding - this is due to either not being tight enough or - in the most cases - of being too flat formed.

HD can be found at animals, humans (also horses, cows, cats, rabbits) and sometimes even at the Wolf or Dingo !!

For humans it can be pointed out already at the time of birth - unfortunately this does not apply to dogs because the bones of the hips are not finally developed at this time - the bones become more tight and develop during the phases of growing up-period.

The Musculus pectineus at the inner side of the tight is said to have a certain influence to the HD.

It is supposed that puppies which have less muscles-fibres there than other puppies are most likely will develop some HD.

Good musculature is important anyway and a dog with a more muscular back legs might suffer less if there is some HD.

Hormonal influence

The natural hormones circulating with the blood can cause ¨looser¨hips than regular - esp. the Estrogen.

It is proven that bitches when X-rayed at the time of the Estrus show more loose hips than om Anestrus

- Advice for the breeders : never do the HD-X-ray during or around the period of Estrus !

Important remark: Please keep in mind :

I’m neither a veterinarian nor a native English speaker – and the author Mr. Willis is English!

I tried to do my best with the translation – and any misinterpretation 
will be due to the mentioned facts.

Those who are interested to read the book - and I highly recommend to read it as 
it is written in a way that almost everybody will understand it - 
should order it

(evtl. ask the Leonberger Club GB for the address where to order it or search 
online for the Witherby LTD.  to order directly).

I was blamed enough in the past for "free speech on sensitive matters", 
information available to everybody who asked for,
 for being willing to share my poor knowledge with other’s 
and therefore I hope that those who might read this do not belong to 
that typ of humans !

I can assure you that "to put down my reputation" doesn't change anything;
neither my mind nor the facts - and I've got already reassurance from professionals.