Familial hypercholesterolemia in Eurasiers
Author: Rita Vaszilová (translated from Slovak)
The Eurasier community has recently been paying more and more attention to a new and very pressing topic – severe (familial) hypercholesterolemia. What do we know about this disease so far, how is it inherited, what research is currently under way and how can each of us take part?
Testing is free of charge. You will find how to take part below, in the section Who can take part in the research and how?
What is the disease and what does it cause?
Hypercholesterolemia is a disease associated with extremely high blood cholesterol levels. There are two forms – primary and secondary.
- Secondary hypercholesterolemia may be related to other diseases, such as hypothyroidism.
- Primary hypercholesterolemia occurs as a disease in its own right, and it is its hereditary form that is the subject of current research in Eurasiers.
In severe disorders of fat metabolism, fats may be deposited in tissues and blood vessels. This leads to a high risk of serious health complications such as stroke-like neurological episodes, pancreatitis, and thrombotic and vascular complications including atherosclerosis, in which the arteries narrow and become damaged. Various organs may be at risk, including the heart, liver and kidneys.
In some cases, neurological signs resembling epileptic seizures have also been described. The disease manifests very quickly and affected dogs die before the age of two. Unfortunately, according to the information available, no effective treatment has been found yet, and even treated dogs do not live much longer than four years. This makes prevention all the more important.
Important: This is not just about a raised blood cholesterol value. A severe disorder of cholesterol metabolism can seriously affect a dog's quality of life.
Although the topic has only recently received more attention, according to some sources cases were recorded as early as 2016–2017. Several cases are currently known in Europe, as well as one affected litter in the USA. However, since the disease is not yet sufficiently mapped in Eurasiers and can be difficult to diagnose, there may be further cases that were not reported or where the real cause of death could not be determined.
Ongoing research brings hope
The good news is that a research collaboration between the University of Minnesota and the University of Bern has identified a gene that is very likely responsible for the disease.
To confirm the results and continue the research, however, a larger number of samples is needed. This is where we can all help.
The more samples are collected, the better researchers can study the frequency of the genetic variant, identify at-risk lines, get a more accurate picture of the situation in the breed and also detect dogs in which the disease has not yet manifested.
How is hypercholesterolemia inherited?
More good news is that, according to the research results so far, it is a monogenic recessive hereditary disease. The mode of inheritance is therefore similar to DWLM.
What does this mean in practice?
- To be genetically affected, a dog must inherit two copies of the risk variant – one from each parent.
- A dog that inherits only one copy becomes a carrier.
- A risky mating occurs when both parents are carriers of the same recessive variant.
When two carriers are mated, each puppy has the following probability of being:
| Puppy | Probability |
|---|---|
| genetically affected | 25 % |
| carrier | 50 % |
| free of the variant | 25 % |
This is why clubs abroad strongly recommend genetic testing of all breeding dogs. Test results allow us to avoid risky matings and reduce the likelihood of genetically affected puppies being born.
This does not automatically mean that all carriers should be excluded from breeding. By choosing a partner that does not carry the variant, the birth of genetically affected puppies can be prevented. Excluding all carriers from breeding could also needlessly reduce the genetic diversity of the breed – which would not be ideal either.
Some sources also mention that carriers might show certain signs of the disease. This question, however, requires further research.
Who can take part in the research and how?
Testing is free of charge provided the samples are sent within the set deadline and in line with the research conditions.
Every Eurasier owner can take part, including owners of puppies!
Samples are taken:
- from blood,
- by cheek swab.
Both universities test blood samples. The University of Minnesota also accepts cheek swabs.
The universities can work better with blood samples. From a practical point of view, we recommend considering sending samples primarily to the University of Bern – because of customs regulations and the more complicated, often more expensive shipping of samples to the USA. There are also reports that the University of Minnesota has already collected enough samples and is asking owners in Europe to prefer working with the University of Bern.
Information on sampling and shipping:
- University of Bern (Switzerland): sampling and shipping instructions
- University of Minnesota (USA): sampling and shipping instructions
Don't forget: If you decide to send samples, include a copy of the tested dog's pedigree as instructed by the respective laboratory.
Why should we take part?
Even though the number of affected dogs known so far may not seem alarming, we still lack information on which lines carry this genetic variant and how widespread it is in the Eurasier population.
Every mating of two untested dogs is therefore a game of Russian roulette – we do not know how it will turn out, and future generations of puppies may pay for our ignorance or indifference with their health or, in the worst case, their lives. This applies without exception to every disease.
Without enough genetic tests, we cannot reliably map the situation in the breeding population or find out how many dogs are carriers or genetically affected. That is why it is important for as many owners as possible to take part – whether their dog is actively used for breeding or is primarily a family companion.
Every sample can help. In this situation, it is important to join forces, cooperate and support research that can significantly contribute to a better understanding of the disease and to protecting the health of future generations of Eurasiers.
Where can you find more information?
We also recommend following the Facebook pages of the French and American Eurasier clubs, which regularly report on the progress of the research and new findings:
Help uncover further connections, better map the occurrence of this genetic variant and contribute to more responsible planning of future litters. Please share this information so that it reaches as many Eurasier owners as possible. The more of us cooperate, the more we can learn.
Minor inaccuracies reserved.