DYSERYTHROPOIETIC ANAEMIA AND MYOPATHY SYNDROME (DAMS)
STATEMENT FROM ESS HEALTH CO-ORDINATORS – JULY 2023
WHAT IS DAMS?
In August 2022, a scientific paper was published which identified a genetic mutation that causes
Dyserythropoietic Anaemia and Myopathy Syndrome (DAMS) in English Springer Spaniels. The study
looked at a family of 26 show-type ESS from Sweden which included five affected with DAMS, two that
died shortly before or after birth, and 19 unaffected. It also included two previously (in 1991) studied
dogs from Australia affected by DAMS, which were distantly related to the Swedish dogs.
As with other genetic diseases such as Fucosidosis, DAMS is inherited through an autosomal recessive
trait. Autosomal means that it can it can affect both males and females. Recessive means that for a
dog to be affected, it must inherit two copies of the mutant gene (one from each parent).
WHAT ARE THE SYMPTOMS AND IMPACT OF DAMS?
DAMS is an early onset high impact disease that significantly and increasingly affects the dog's quality
of life. The affected Swedish dogs in the study had to be euthanised between the ages of 1-7 years.
Typical symptoms fall into two main categories:
Dyserythropoiesis: Defect in the development of red blood cells resulting in anaemia, with too few
and small red blood cells, containing less haemoglobin than normal, affecting the ability to bind and
transport oxygen. The bone marrow then increases production and sends out immature red blood cells
that have a poorer ability to transport oxygen.
Polymyopathy: Impaired muscle function in several muscles. This may show as weakness, pain from
the muscles, muscle wastage, limping gait, difficulty opening the mouth wide and chewing, and
enlarged oesophagus (megaesophagus), causing difficulty swallowing, regurgitation and even lifethreatening pneumonia.
Affected dogs begin to show symptoms shortly after birth and muscle wasting progresses over time
until the dog can no longer walk, jump, eat, drink and move freely. It varies individually in how long it
takes before the symptoms increase to such an extent that the dog can no longer live with the disease.
Two of the Australian dogs studied in 1991 also had an enlarged heart (cardiomyopathy), but that was
not observed in any of the Swedish dogs autopsied.
IS THERE A DNA TEST?
Following the discovery of the DAMS mutation, a DNA test has been developed and is currently being
offered in the UK by Laboklin Laboratory. Fortunately, recessive inheritance means it is safe to breed
from carriers without risk of producing affected offspring, provided they are mated to dogs that are
known to be clear of the mutation. This enables a wider selection of dogs with desirable characteristics
(that otherwise appear healthy) to remain in the breeding pool to help maintain genetic diversity in
Although some of the symptoms overlap (muscle wastage, difficulty opening the mouth wide and
chewing), it’s important not to confuse DAMS with MMM (Masticatory Muscle Myositis). Unlike
DAMS, MMM is an autoimmune condition in which a specific type of muscle fibre found only in the
chewing muscles of the jaw and skull is attacked and destroyed by the body’s own immune system.
Sadly, there is no DNA test for MMM.
Note: DAMS has also been identified in Labrador Retrievers - although their mutation is in the same
gene (EHBP1L1) as the ESS mutation, it is a different variant so the DNA tests are different for each
THE STORY SO FAR AND WHERE DO WE GO FROM HERE?
A number of ESS breeders in Scandinavia have already used the DAMS DNA test and there appears to
be a carrier rate of around 20% of those tested. Although there are substantial differences between
the UK and Scandinavian ESS gene pools, there is also a significant crossover, with some UK show lines
in the Scandinavian gene pool and vice versa. Some of the Scandinavian dogs with the mutation go
back in part to UK lines, so several concerned UK breeders have now decided to test some or even all
of their current stock. At this stage, we simply have no idea of the mutation frequency in the overall
UK ESS population, as it would need a large number of dogs from across the breed to be tested for us
to have any meaningful indication. Yet at the same time, the breeding community won’t want to test
for a condition they've never heard of and which as far as they're concerned isn't a problem in the
breed. It’s a classic chicken and egg situation.
That said, we obviously need to gather whatever data we can, and our first priority is to ask the Kennel
Club to introduce an official DNA Breed Test Scheme for DAMS (as we have for Fucosidosis, PRA Cord1,
AMS and PFK), so that all DAMS DNA test results can be automatically recorded on registration records
and published on the KC website. This would make the results accessible to everyone and provide
much needed data. We’re asking the ESS Breed Clubs if they agree with this proposal, as it needs
majority support to go forward. The KC also has to carry out its own checks to confirm that the DNA
test is based on robust science, that it’s offered by a KC approved laboratory (to protect the integrity
of results that appear on a dog’s record) and is relevant in the breed (many DNA tests exist but aren't
always relevant). In the meantime, to their great credit, breeders recognise the importance of publicly
sharing their dogs' test results and several have opted to register the results on the privately
administered Spaniel database on the Fleckenbase website (albeit this isn’t an official registration
database and doesn’t guarantee the accuracy of the information given, but at least it’s something until
we can hopefully get an official KC scheme up and running).
It's important to bear in mind that show-type ESS are only a tiny proportion of the overall ESS
population in the UK. ‘Recommended’ health tests apply across the breed (we don’t have different
lists for different sub-groups) and, with the information currently available, it’s too soon to know
whether DAMS should be classified as a priority ESS health test. That said, it's important to stress that
we would encourage and support any breeders who are concerned that the DAMS mutation might
affect their current breeding lines and want to avoid any possibility of producing affected dogs, to
use the DNA test for their own peace of mind as well as contributing towards much needed data.
Obviously, we'll be keeping a close eye on developments and we could be faced with a number of
different scenarios depending on the results of the tests currently being carried out by UK breeders.
We’re also due to meet with members of the Kennel Club health team to discuss the situation and
explore any additional options that might help to give us an indication of the DAMS mutation frequency
in the UK ESS population. When we’re in a position to do so, and in consultation with the ESS Breed
Clubs and the KC, we can decide whether or not DAMS should be a recommended priority health test
across the breed.
Louise Scott / Lesley Field
ESS Breed Health Co-ordinators
DYSERYTHROPOIETIC ANAEMIA AND MYOPATHY SYNDROME (DAMS)