Acral Mutilation Syndrome (AMS)
What is Acral Mutilation Syndrome (AMS)?
Acral Mutilation Syndrome (AMS) is an inherited neurological disorder that causes abnormal development and slow degeneration of the pathways that carry sensory (i.e. hot, cold, pain) messages to and from the brain along the spinal cord through to the peripheral nerves in the feet. Dogs affected by AMS gradually lose feeling in their toes and feet (sometimes the whole of the leg may be involved). Clinical signs can range initially from mild swelling, discomfort and pain, to raw open wounds, abscess and sometimes a reluctance to move.
As the loss of sensation progresses, dogs affected by this devastating condition often chew their toes, feet, paw pads and limbs, causing extensive mutilation and damage, sometimes even to the point of self-amputation. There is no known cure for AMS.
What is the cause of AMS?
AMS is a genetic condition caused by a simple autosomal recessive mutation. In order to produce an affected dog, both parents must carry the defective mutation. Breeds known to be affected by this condition are French Spaniel, German Short Haired Pointer, Pointer, Cocker Spaniel and English Springer Spaniel.
What are the symptoms?
The first signs can usually be observed in young dogs between 3 to 12 months of age.
Symptoms seen include:
Excessive licking and/or chewing of feet/legs
Abscess & raw wounds
Effusion (swelling)
Lameness
Inflammation of joints
Behavioural changes
Loss of co-ordination
Disorientation
One can see ulceration on feet and legs, however the dog feels no pain and will often continue to walk normally (putting full weight on their damaged limbs) without showing any sign of discomfort.
What is the treatment?
The outlook is poor for affected dogs. Vets may provide treatment to try and limit further self-mutilation through the use of bandages, Elizabethan collar and sometimes sedation. It is also essential to provide a stress-free living environment for affected dogs, keeping water and food bowls within easy reach, avoiding exercise and physical activity, noise or any kind of commotion. All of this will not, however, affect the prognosis and the condition will worsen, with euthanasia the usual outcome at a young age.
How can AMS be prevented?
A simple DNA test is available for AMS
AMS is a completely preventable disease, thanks to the availability of a DNA test that will confirm the genetic status of each dog as either:
CLEAR: The dog has two normal copies of the AMS gene. It will not have AMS, nor can it pass on the mutant gene to any offspring;
CARRIER: The dog has one normal copy and one mutant copy of the AMS gene. It will not suffer clinically with AMS themselves, but it can pass on the mutant gene to its offspring;
AFFECTED: The dog has two mutant copies of the AMS gene. It will be clinically affected with AMS and will always pass on the mutant gene to any offspring.
Affected puppies cannot be produced if at least one parent in any mating is genetically Clear.
DNA Test Procedure:
The AMS test uses a buccal (cheek) swab for DNA analysis, a completely non-invasive method of sample collection.
The sample can be collected by owners or by a qualified Vet if owners prefer the sample ID to be independently verified.
Kennel Club Recording of AMS DNA Test Results
An official ESS/Kennel Club Breed Scheme is in place, whereby AMS DNA test results notified to the KC will be added to the dog’s registration details and will appear on any new registration certificate issued for the dog and on the registration certificates of any future offspring of the dog. The results will be published in the Breed Records Supplement and appear on the Health Test Results Finder on the Kennel Club website.
AMS DNA testing is a 'Best Practice' health test under the Kennel Club Health Standard for ESS (or dogs must be "hereditarily clear").
To find AMS test results for individual dogs click on Health Test Results Finder.
To find lists of AMS tested dogs and their genetic status, click HERE. Scroll down to 'Health' and click on 'More about health', then 'Other health schemes and tests available'. **These lists do not include ‘hereditarily clear’ dogs (i.e. dogs that have themselves not been tested as they are the product of two CLEAR parents).
How common is the AMS mutation in the UK ESS population?
A study to estimate the frequency of the AMS mutation in the UK ESS population was carried out in 2018 by geneticists at the Animal Health Trust. It was initiated by the UK ESS Breed Clubs in order to gather evidence to enable breeders to make informed decisions as to whether they should be routinely using the AMS DNA test.
The study used a large bank of ESS DNA samples originally donated to the AHT in 2016 for research into PRA. 591 ESS DNA samples were randomly selected from a total bank of 922 and screened for the AMS mutation - the identities and genetic status of the dogs whose samples were used will remain anonymous.
Results:
The study found that 16 of the 591 samples had one copy of the mutation (i.e. they were carriers).
Using the Hardy-Weinberg Principle, the study estimated that 97.31% of ESS in the UK are free from the AMS mutation, 2.67% are carriers and 0.02% will be affected (which equates to 2 affected dogs per 10,000).
Conclusions:
The results indicate that the mutation frequency is very low. However, these estimates are based on the assumption that all matings take place randomly throughout the ESS population. In reality, most matings are highly selective and within separate ESS sub groups, which immediately affects the risks significantly. Even with a low number of carriers overall, without knowing exactly where they are, breeders could be taking a risk with a mutation that may have devastating consequences.
Breeding Advice:
When deciding whether to use the AMS DNA test, breeders should consider the high impact of this traumatic disease, which strikes when dogs are very young and usually leads to euthanasia after a short period. Therefore, even with a low mutation frequency across the Breed as a whole, we would encourage and support any breeders who want to avoid any risk of producing affected puppies by DNA testing their ESS before breeding from them and ensuring that at least one parent in any proposed mating is genetically CLEAR.
If any ESS owner and/or breeder needs help or further information relating to AMS, we would be happy to hear from them. We would also be extremely grateful if ESS owners would help us to monitor AMS in ESS by reporting online any confirmed diagnosis of AMS or the death of your ESS from the disease. All information provided will be treated in the strictest confidence.
For further information or advice about AMS, please contact the
