The genetic situation in the Leo

The genetic situation in the Leonberger

- ideas on how to diminish high COI and loss of ancestors
- less unique/single ancestors
- inbreeding and line breeding which minimize the breeding pool

Probably the majority of purebred dogs, including the Leonberger go back to a few (closely related) foundation dogs.

Historically caused bottlenecks (due to two World Wars and loss of breeding potential) made the situation worse, this also holds true for more breeds on the European continent.

These questions are often heard (combined with criticism about purebred dogs, lack of health etc.)

The answer is “yes” – we need our purebred dogs, we need each breed – but we also need to set different goals to help us with the multiple problems (lessened disease resistance, reduced vitality, short lifespan etc).

In Dr. H. Wachtel’s book ( Titled “dog breeding in the millennium”) we read :

“but not hybrids, mixes are the solution but the heterozygote and genetic variable bred dog;”

The only way could be the combined effort of breeders, dog-owners, dog clubs and national kennel clubs – working together – and achieving the best for the breed!

Each breeder and studdog owner can contribute, and consider for themselves what will really become important in „the future of the breed“– even when a breed club does not set rules / regulations for e.g. conc. Health checks and requirements. There exists a chance for the single person to achieve “more than required” – for the sake of the breed.

To succeed or fail – will finally depend on how many breeders are willing to go “a new way” – and a new way means here “as less inbred as possible – a low COI”

Complete out crossing – is not possible – and I doubt if it were ever possible as there was never enough „breeding potential“ (brood bitches / studdogs – unrelated or not closely related). To “stop the bomb ticking” , in other words “to win some time” – is possible!

To “freeze” the COI – to avoid climbing higher and higher, would be possible, this is what this article is about.

To cut a long story short about various data collection and databases – because of those programs we are able to count

Example: a 5 gen-pedigree – max. ancestors 62 –
if a dog has this 62 NOT RELATED / UNIQUE ancestors – it is not inbreed

– but if an ancestors appears 2 x, we deduct the 62 ancestors and the dog has only 60 – and some dogs have only 50 or even less = loss of single / unique ancestors = indicator for inbreeding / linebreeding

Generation I Parentdogs	50 %
Generation II Grandparents	25 %
Generation III Great-grandparents	12.5 %
Generation IV Great-great-Grandp.	6.25 %
Generation V Great-great-great- grandparents	3.125 %

If the same ancestor appears 2 x in gen. 4 = 2 x 6.25 % = 12.5 %
and 2 x in gen. 5 = 2 x 3.125 = 6.25 %
- than the genetic influence of that ancestor is 12.5 + 6.25 % = almost 19% -
therefore higher as a great-grandparent and already closer to the grandparent…….

The new online-databases are run with a program which enables us to do a maximum of 37 generation and it gives us
also the info about unique ancestors resp. the loss of unique ancestors.

These databases had and have the same purpose: to help a breeder to view the potential partner for a bitch or male resp. the pedigree “online”. During all those years that health data (HD – ED – and more) have been added to the databases, it has become a good source for the breeder. Which was the original purpose and still is of the online databases.

IK / COI shows the relationship of an animals parents and is a good indicator for the likelihood that 2 alleles in a gene might
be identical (Wachtel, Hundezucht 2000 pg. 80/81= Dog breeding in the Millennium)
IK is a mathematical term to count the inbreeding of an animal resp. of a population (KRAUTWURST – prakt. Genetik f. Hundezüchter /practical genetics for dog breeders – only in German pg. 202)

AVK – Ahnenverlust-Koeffizient is counted by dividing the real amount of ancestors with the maximal possible amount of ancestors.

All Breeds had once been established via inbreeding and linebreeding, only that way one could achieve the unique characteristics. So they are all homozygote (the same alleles) and this holds true for all good and desired traits also for the high amount of defective genes / mutations.

It is important for a low defect rate in a population that the partners are not closely related, it would be best if they were not related (WACHTEL, Hundezucht 2000, S.20/21) and “COI should not climb higher than 1% - better 0.5 % in a generation (WACHTEL, Hundezucht 2000, S.71).

As exterior and all the breed-specific traits are today fixed – in each breed – there is no reason for linebreeding / inbreeding anymore.

If the breeder knows some basic genetics ( “a breeder ought to know the basis genetics”) than they know as well, which traits are low- medium – highly inheritable and if there is information about the ancestors (conc. exterior, e.g. coat length, colour, eye colour, size, onset ears, tail etc.) a breeder can achieve good results with “like-to-like” breeding and can pay attention to the fact that no common ancestors
(or very few) appear in a 5 gen. pedigree.

If there are “common ancestors” it is advised to get as much information as possible about them (see example – percentage of
genetic impact).

The highly desired “exterior” ( colour , size, deep chest, strong bones) belong to medium – to highly inheritable traits (30-65 % - WILLIS, Genetik der Hundezucht, S. 37) therefore good results are possible to achieve without linebreeding.

Unfortunately, traits we would like to influence, such as vitality, longevity etc. all belong to low-inheritable traits, 10 – 15% and therefore these traits are desirable in the maternal and paternal lines. It is also known that traits such as vitality and longevity go along with heterozygosis.

„heterozygosis is best achieved when mating two not related partners, this not only to avoid defective genes (mutated alleles) but the advantage is a much more vital, strong animal ……………….“(WACHTEL, Hundezucht 2000, S.28).

Each breed or better said each individual carries some defective genes; each dog carries 4 – 5 defective genes (G.A. Padgett,
Control of Genetic Diseases, pg 11). A defective gene is a mutation which causes the outbreak of an inheritable disease. The risk that 2 identical defective genes are present increases, the more the partners are related – and the risk declines, the less they are related.

ZERO risk does not exist, just like there is no 100%- inheritability.
When genetically based tests are available, dogs should be tested ( all dogs, to get an estimate of how far a defect is spread in the population). One problem is that the same disease might follow a different mode of inheritance in the various breeds; this means, not each test can be used for each breed.

After almost one century of collecting data, study of pedigrees and bloodlines and combined efforts of researchers (geneticists, biologists, veterinarians) from Europe and the USA the first genetic test, as of July 2010, for the Leonberger breed is available = the LPN1 Test.

The research teams work with high pressure on the development of a 2^nd test for other forms of Polyneuropathy.

These blood test have already enabled us to gather information on the genetic status of many Leonbergers in the breeding
pool; the overall genetic situation in our breed does however allow us, to use not only N/N = free = clear – tested dogs.

In the future we cannot dismiss dogs with carrier status = D/N = carrier = 1 mutated, 1 clear gene and they will be used for breeding but ONLY with N/N – tested dogs.

Following the recommendations of the researchers we shall replace in each generation the carriers with “N/N = free offspring” and by doing so it shall become possible to “control” this form of the disease in appr. 3 – 4 Generations.

The same procedure shall be applied if the 2^nd genetic test for another form of this disease is available (LPN2 test).

Until then breeders should work with as many good phenotypical results (HD-ED-heart, thyroid check, eye check) of their breeding stock – then breed these thoroughly health-tested dogs to other thoroughly tested, not closely related dogs or ideally not at all related.
However, the genetic situation will not allow us to use only dogs with excellent results (2nd article on breeding program, requirements etc. will follow).

„Breeding means to think ahead in generations “ (KRAUTWURST, prakt. Genetik f. Hundezüchter, S. 11) and achieved titles are not more but also not less than phenotypical recognition of Beauty. Nothing against beautiful looking dogs and of course this is also nothing against Champions –
I like to show my Leos as I am proud of them! – there is nothing wrong with that – but breeding should and does mean much more than just mating 2 beautiful dogs.

Limitations of mating for studdogs – one possibility would be to „freeze“ the COI – but what happens is unfortunately just the opposite. A few of the possibly available studdogs mate all the brood bitches; then the total COI for our breed rises and at the same time we minimize diversity as we breed many “half-siblings” on the paternal side. (WACHTEL, Hundezucht 2000, S.241)

Less stringent ? restrictive ? concerning exterior is not the same as breeding with „ugly looking dogs“– (as is often claimed) –
would lead to a greater amount of dogs in our general breeding pool.

More restrictive concerning the healthwise expectations (examination for HD – ED – evtl. OCD, heart, thyroid, eyes plus the genetic test(s), evtl. complete blood profile once a year) would lead to a breeding with “healthier animals” and therefore hopefully an overall healthier and more vital offspring.

Minimal “freezing” of the COI with previous check of COI and COR per hypothetical pedigree

“The still existing variability in dogs must be preserved and if possible, increased”

(WACHTEL, Hundezucht 2000, S.244) Prof. Dr. I. Stur (Univ. Vienna) recommends that potential puppy buyers check the COI of
a puppy (as low COI means reduced risk for rec. traits) – Citation Wuff 7/8/96 and WACHTEL, Hundezucht 2000, S.254)

Rotation breeding - (WACHTEL, Hundezucht 2000, S.178) for the beginning just breed with dogs which have for at least 3 generations no common ancestors – at the same time limitation of matings for studdogs –R.G. Beilharz – Univ. Melbourne, citation in ((WACHTEL, Hundezucht 2000, S.178)

“conservation of genetic material (sperm and embryons) at gene banks (WACHTEL, Hundezucht 2000, S.192)
The use of frozen semen could mean a kind of “genetic kick” for future generations and this new technology could
help us to save what we might need in the future.

"It looks as if the today’s dog-generation is healthier than the next one – but not as healthy as the previous one……………"(WACHTEL, Hundezucht 2000, S.192)

And (WACHTEL, Hundezucht 2000, S. 57) „….the import of Semen of males from other areas – out of other combinations – would refresh the genpool."

If semen from males who made it without extreme efforts and neglectable health deficits to a relatively high age – and if that males had even not been over-used “at their time” but gave good offspring with various bitches, then we should surely use such semen as it would add “something good in the sense of vitality and longevity” to our breed.

Also older studdogs who did not produce overly – and produced again good offspring with various bitches – should be preferred – and if there is an otherwise vital 8 – 9 or even 10 (and ? more ?) years old studdog is not longer able to “mate naturally” – we should use all the advantages of modern technology and the service of veterinary reproduction specialists.

At the same time studdog-owners who do not allow their male to breed overly, should think of the advantage of conservation of sperm – as such a healthy and vital studdog – probably just not much used cause being “out of fashion” (cause too dark, too light, too thin, coat too short, no titles) would in the future be “a Plus” for the genpool.

The absolutely „last chance to preserve the Leonberger as we know and like this breed“ would be a real outcross in
the sense of choosing a partner of a similar breed (e.g. Newfoundland, Landseer, ???).

In the history of the Leonberger we have heard of several such “crossings” (due to lack of breedable specimen after World War etc.) – some of that is documented, some of that is “hearsay” (I have heard it through the grapevine ……)

„….was a Newfoundland in Switzerland crossed with a Berenese Mountain bitch; in 3rd Generation a descendant of this combination already became World Winner of Bernese Mountain dogs………….“!

“citation H. Spengler (1994) – cross of a Newfoundland with a Leonberger, 2 granddaughters of these combinations became the foundation bitches of the Netherlands breeding pool…………….there have been other crosses with the Leonberger……..also crosses of Newfoundland dogs and Kuvasz with the Landseer…………”

A game I like to play “what kind of breeds might be in the Leonberger” ? (and I do not refer to the History as we have learned it) –
the above mentioned cross with the Newfoundland is documentated and also mentioned in Leonberger publications and studbooks (and in 2 themes about the Leonberger – Monographic, development of breeding in the GDR). I will not mention the other crosses as I do not have evidence to proof (only verbal sources) but it does not matter.

Those crosses have surely not done any damage but did probably already help our breed to „survive“ despite the small breeding pool, despite the high COI – as they all have lead to more genetic diversity – IMO this could be the reason that the breed did tolerate the lack of diversity that long, we are now confrontated with many “unwanted recessive” traits, lack of diversity and vitality and low lifespan. (Inbreeding depression)

But first we should immediately use the fore mentioned methods to avoid any “climbing” of COI as “cross with another
(related) breed means a lot of preparation and the willingness of Breed-Clubs and national kennel clubs to work together

– and all this needs much time

As I have mentioned excessively the COI and diversity, I feel that I should show up with some tables and no. to make all that
“visible and better understandable”.

Table – COI and AVK – real no. of not related / not common / unique / single ancestors

The examples above show that even the „not much inbred/ linebred “ Leonbergers suffer from an enormous loss of diversity,
the more generations we check backwards.

The no. of Leonbergers belonging to the German Breeding Pool (VDH-FCI) is
326 individual Leonbergers; 113 studdogs and 213 brood-bitches.

Unfortunately the studdogs are not equally used and are also partly related
(father – son, brothers, cousins): also the studdogs are partly related with the bitches and the bitches are related too
(mother – daughter, sisters, half-sister’s etc.).

To make a guess I would say that appr. 40% of the studdogs are used more often than the rest –
and out of this 40% about half of them are overly used.

Also foreign studdogs are used which is positive as it would mean “more diversity”, however, there is often an imported bitch,
related to the chosen foreign studdog – or the foreign studdogs are also overly used in their country – crossing borders does not
mean that much anymore these days – the contribution to diversity is probably less than it could be.

is counted by a formula 4 x available males x available females – parted thru the amount of all reproductors
(this would mean for the German population 4 x 113 x 213 ./. 326) – and this amount is very low !

I feel as well the need to mention that breeders need the support of the potential puppy buyers, later, Leonberger owners.
As far as a “fair and open-minded exchange of information” is concerned – this kind of “feedback” is necessary –
as well fairness an absolute must is if “something negative” might happen, the first concern should always be to help the dog
(and not to blame the breeder or to shift the blame from one to the other or – even worse – to tell lies,
blame people officially on the internet etc.). This doesn’t help anybody and doesn’t contribute to anyone or anything.

Support should be given to those breeders who try to select the low-inheritable traits such as vitality, longevity etc.,
those who try to breed dogs with a low COI – compared to the average of the breed.

Unfortunately not enough credit is given for this approach and not always supported by the puppy buyers and future owners
of the Leonbergers – if a breeder is left to themselves – fighting windmills like Don Quichote, or attacked by those
who should support them , we must not be astonished by the fact that only very few breeders are willing to breed
for health, vitality, longevity and diversity and to give any “new ideas and possible breeding programs” a chance.

“One thing is for sure:

even the very best breeder cannot give any guarantee that a dog,

will be free from any genetic defect”

Dr. George A. Padgett – Control of Canine Genetic Diseases – Howell Book House
N.Y. 1998

Eric H.W.Aldington, Friedern Stockmann
– Vom Körperbau des Hundes – 5.Aufl. Kynos-Verlag

A big "THANK YOU" goes to Dr. H. Wachtel who was willing to read the German version of this article !

Another big „THANK YOU“ goes to my friend Christina, who put the article in an „elegant English instead of my partly humbly one“ J
and who also checked for proper grammar !