Welcome to the Dobermann Longevity DatabaseNames, dates of birth and dates of death have been obtained from freely available sources in the public domain.
The accuracy of this data and any statistics - such as longevity, COI, AVK - cannot be guaranteed.
With your support we can produce a valuable resource to help all owners and breeders.
We thank the large number of people who have contributed to the database in the past. Without their support this resource would not be available.
A simple introduction to Genetic Diversity and Statistical Risk Assessment
The breeder/owner tools on this website provide statistical estimates of Genetic Diversity.
There are consequences for all Dobermanns being genetically similar, some good, some bad. The fact that dogs within individual breeds are so genetically similar is what makes them that breed- and why , if you breed any Dobermann to any other Dobermann, the puppies will look recognisably like Dobermanns.
Many of the 20,000-odd genes that go into any dog of a particular breed are ‘fixed’. That means that every Dobermann will have two identical copies of them- one inherited from their dam; one from their sire. Others however, are not so fixed – such as those genes that determine the colour of a Dobermann.
Genes always come in pairs. The gene-pair is called an ‘allele’. When the pair is identical, it is called ‘homozygous’. When the pair is not identical, it is called ‘heterozygous.’
‘Allele’, ‘homozygous’ and ‘heterozygous’ are three good words to understand if you are a dog breeder or owner.
Homozygous and heterozygous are terms often used more generally, too, when talking about diversity.
The more gene-pairs that are homozygous = less diversity
The more gene-pairs that are heterozygous = more diversity
Geneticists in the main consider diversity a good thing.So not all the pairs of genes are identical?
Correct. And this is what gives us variation within a breed. It’s why, as mentioned above, Dobermanns come in different colours. And it’s also what makes some bigger or shorter or faster or cleverer or more able to withstand disease than others. Of course environment can play a big role too, but the raw potential for every dog lies in its genes.Risk assessment and health
There are many health problems associated with the Dobermann
ie vWD (blood disorder), PHPV (eye problem), hip dysplasia, DCM (heart disease), cancer.
These health problems are associated with certain gene defects or combinations.
Huge progress has been made by breeders in understanding how to reduce the risk of puppies having blood, eye and hip problems. The major problem facing breeders today is reducing the risk of early deaths due to the more complex diseases such as heart and cancer.Can we reduce the risk for some diseases?
Testing methods are available to screen for the early signs of blood, eye and hip problems. Responsible breeders already use a variety of health tests to identify which Dobermanns have the highest risk of passing on these health problems to their offspring.Can we reduce the risk for more complex diseases?
The cause of heart disease, sudden death and cancer have not been so easy to identify. It is now thought that heart disease could be caused by a complex mix of gene combinations or gene defects – and only a small number of these gene have been identified.
When you don’t know which genes are responsible for a disease – it becomes very difficult to know which breeding choices carry the highest risk.
The challenge for breeders is to make risk assessments to gain more time for academic research to find the answers.
Possible strategies that might reduce the risk of heart disease and sudden death include:
Selecting Dobermanns for greater genetic diversity
Selecting Dobermanns that appear to have high longevity over 3-4 generations
Selecting Dobermanns that appear to show a lower incidence of heart related problems in their offspring over 3-4 generations
Breeding choices should not be based on guesswork.Can we improve the breed by screening out all Dobermanns with health problems?
This is not a sensible strategy. If breeders screen all dogs for all known health problems and use only those that have the lowest risk we would create even more problems by reducing the available gene pool of breeding Dobermanns.
The Dobermann breed already has a low level of genetic diversity, so it is inevitable that breeders will need to breed from Dobermanns that have known health problems. Breeders will always have difficult choices to make when choosing suitable Dobermanns for breeding ….. but it is also responsible for breeders to inform owners of their puppies of potential health risks.
The breeding tools on this website give simple statistical predictions of genetic diversity. If the pedigree is incomplete, or inaccurate these predictions will be less reliable.Predicted Genetic Diversity for the whole litter
The breeding tools on this website give ONE statistical prediction which represents the genetic diversity for the WHOLE LITTER.
In practice, each individual puppy in a litter will have different levels of diversity.Actual Genetic Diversity testing for each puppy
The only way to measure the actual genetic diversity for each puppy in a litter is by gene testing each puppy.
Improved Genetic diversity is generally considered as a positive step to take by responsible breeders.
COI stands for Coefficient of Inbreeding. Essentially, it measures the common ancestors of dam and sire, and indicates the probability of how genetically similar they are.
The COI is really just measuring the statistical probability of any individual allele being homozygous due to an identical gene being passed down to the puppy along both the dam and sires lines from single common ancestors.Give us a dead simple example
Breed two completely unrelated Dobermanns
Mate two of their offspring together
What is the resulting puppies’ COI?
In this instance the puppies’ COI will be 25% – that is, statistically, there is a 25% chance that any allele will contain the exact same gene as a direct result of having common ancestors – in this instance the same grandparents. This is in addition to the levels of homozygosity that would be present in the breed regardless.You say ‘statistically’?
This statistical estimate will give the same value for every puppy in the litter.
In reality, there could be a wide variation in diversity between every puppy in the same litter. Some puppies in the same litter could be much more than 25% genetically identical/homozygous – and other much less.
The only way to know for sure would be to minutely examine every dog’s genetic fingerprint (or should that be pawprint?). At the moment there are two diversity testing projects that offer affordable ways to measure the actual genetic diversity of individual Dobermanns.
The statistical estimate is nevertheless very useful risk assessment tool for dog breeders and owners.What about other COI examples?
Full sibling: 25%
Half sibling: 12.5%
Great grandparents/great grandchild: 6.25%
First cousin: 6.25%
COIs are much more than looking at a dog’s parents. COIs also track how related dogs are further back in the pedigree. Look back 12 generations in our own family trees and you are very unlikely to see the same name twice. This is not true for dogs, though. The same names can appear many, many times. Traditionally, breeders have very commonly used grandfather/grand-daughter matings (and often even closer) to ‘fix’ certain traits.
To get a true picture of how inbred a certain dog is, then, you should go back at least five generations and ideally ten. As you go further back, in most instances, the COI is likely to rise.Why are high COIs considered a problem?
- Inbreeding will help cement ‘good’ traits but there’s a danger of it also cementing bad ones. In particular, it can cause the rapid build up of disease genes in a population.
- Even if a breed of dog is lucky enough to be free of serious genetic disorders, inbreeding is likely to affect our dogs in more subtle, but no less serious, ways.
These include smaller litter sizes, less vigorous/viable puppies, fertility problems and weakened immune systems. These effects have been very well documented in other species and are known as inbreeding depression.
Now nothing in genetics is inevitable. There are some examples out there of very inbred populations that appear to be pretty healthy and whose fertility/fecundity have not been affected. But the above effects have been observed far too often to ignore the risk. While a low COI does not guarantee a healthy puppy, a high COI should definitely be a cause for concern.Why bother to check a dog’s COI?
As well as limiting further genetic problems, having a low COI may show that the breeder has tried to follow good breeding practice and limit inbreeding. This hopefully will reflect in other good practices such as socialisation and worm control so that your new puppy will be happier and healthier in many respects.
COIs can be predicted using different mathematical formulae. On this website we use two different methods – VanRadens method (for pedigrees up to 8 generations) and Miller/Quaas method (for pedigrees over 8 generations).
Coefficient of Inbreeding : Low is good. High is bad
AVK stands for Ancestor Loss Coefficient. It measures the number of different (unique) ancestors there are in a dog’s pedigree.Why should I care?
This number is a simple measure of the genetic diversity in the genes of a Dobermann.
In the ideal case every ancestor in a pedigree will be different. When this happens there is no ancestor loss and the AVK value is 100%
How many unique ancestors could there be in a pedigree?
5 generation pedigree: 62 unique ancestors
6 generation pedigree: 126 unique ancestors
8 generation pedigree: 510 unique ancestors
10 generation pedigree: 2046 unique ancestors
When a particular ancestor is used more than once in a pedigree, the AVK value will start to decrease showing a loss in diversity.
Ancestor Loss Coefficient : High % is good (high diversity). Low % is bad (low diversity)
It is a direct measure of the shared ancestry between the two parents of a Dobermann.Why should I care?
In an ideal case both parents will be totally different – they will have no shared ancestry. When this happens the Coefficient of Relationship has a value of 0%
Coefficient of Relationship = 0%: No shared ancestry between the parents
Coefficient of Relationship = 50%: Parents are siblings (as long as an ancestor is not repeated).
Coefficient of Relationship = 80%: Parents are siblings from a highly inbred line.
Coefficient of Relationship = 100%: The parents are identical twins
Most mating combinations will have Coefficient of Relationships between 0 and 50%
Coefficient of Relationship between parents : High % is bad (low diversity). Low % is good (high diversity)
Estimated Breeding Values (EBVs) are statistical tools that can help breeders make breeding choices based on indicators of the genetic risk of complex inherited disease, which is more accurate than by using an individual dog’s test score alone. EBV calculations have been successfully used with hip and elbow screening data and pedigree information from the individual dog and its surrounding family, to more effectively determine the genetic risk that each dog will pass this disease to its progeny.
They have been used for many years to help improve the temperament of Labradors used in Guide dogs for the Blind, and to improve milk and meat production in cattle.
EVBs require powerful computer systems to maintain accurate breed averages for a particular trait.
On this website three different ways are used to display the ancestors in a pedigree.
Traditional pedigrees expand horizontally – that is, they are read from left to right with relatively few dogs appearing at the far left and increasing to a larger number of ancestors listed to the right. Although the dogs to the left (1 sire, 1 dam, and 4 grandparents) have the greatest impact the resulting offspring, there are only a small number, 6, contributing data on this type of pedigree.
While a greater number of dogs are named on the right side of the pedigree, these more distantly related dogs are less significant genetically than are those on the left.
A vertical pedigree overcomes this problem by including with a dog all of its’ full siblings.
All of the littermates taken as a group represent various combinations of their parents’ genes, and are good indicators of the range of possibilities that are likely to be passed on from any one of them. Likewise, phenotypic information about the aunts and uncles of a given dog, is equally as important as is that of the grandparents. Thus, dogs who do not even appear on traditional horizontal pedigrees, may be more significant genetically than are the more distant relatives who do.
Whenever multiple genes and/or other complex modes of inheritance are involved, a larger sampling will be more likely to contain enough individuals to indicate a pattern.
The vertical pedigree on this website shows the full siblings from the same birth year for each of the first 3 generations.
|Sire and dam each contribute 50% of a pedigree: (2 ancestors in generation 1)|
Grandsires and granddams each contribute 25%: (4 ancestors in generation 2)
Great-grandparents contribute 12.5%: (8 ancestors in generation 3)
In each generation the total number of ancestors add up to 100%
Ancestors to the left of the pedigree are more significant genetically.
Ancestors to the right are less significant genetically.
|In any Dobermann pedigree, it is common for the same ancestor to appear many times.|
for example, the same ancestor could be both a grandparent (generation 2 = 25%) and a great-grandparent (generation 3 = 12.5%).
When this happens, this ancestor will have a Blood Quota of 37.5% (25 + 12.5).
When ancestors are repeated in a pedigree they become more significant genetically.
The higher the Blood Quota the more genetically significant the dog becomes.
The Blood Quota display also conveniently displays all the ancestors in a 12 generation pedigree on a single page.
A Genetic Pedigree shows each ancestor once. Circles represent females and squares males. Colour coding is used to highlight those ancestors affected by a particular genetic trait.
Genetic Pedigrees are interesting because they can be used to do some detective work and are often used to study the genetics of inherited diseases.
Unfortunately, the penetrance of a gene mutation makes this detective work more complicated. For heart disease, some Dobermanns will carry the defective genes, but show very few clinical signs of the disease. It is possible for these dogs to live an apparently healthy life for many years before the symptoms start to show. For others, the opposite is the case, they will carry the defective genes and die at a very young age.
All dogs will have a year of birth - if not known these will be estimated from close ancestors. (completed)
Using the years of birth, data error checking can be simplified. (ongoing)
Where matings have taken place using artificial insemination the name of the progeny will have (AI?) added. (started)
The source of all health data and cause of death will be classified according to the integrity of the source. (started)
Expand/collapse panels used to display notes/help. (completed)
Help files added to explain the breeding tools. (completed)
User comments to correct mistakes. (testing)
User test results to add new test data. (testing)
User dogs to add new records. (testing)
Extend test results section. (completed)
Pagination class http://www.mis-algoritmos.com
Kinship/COI routines from Jacques Le Renard - http://www.somali.asso.fr/eros/
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