Acral Mutilation Syndrome (AMS)

last updated 11/1/2025

GDNF-Type

Acral Mutilation Syndrome (AMS) causes an insensitivity to pain, leading to a tendency to lick or bite or even self-mutilate their distal extremities (often the paws) excessively. This often results in loss of toenails, fractures, and toe amputation and are subject to additional complications from secondary infections.

The disease often emerges around 4 months of age in affected puppies. The proprioception, motor abilities and spinal reflexes remain intact. And pain perception becomes progressively normal above the knees and is not altered in the rest of the body.

Since affected dogs are unable to feel pain in their feet, they will continue to walk without obvious discomfort. Some affected dogs show insensitivity to pain but no self-mutilation, making diagnosis extremely difficult.

Clinical signs of the disease typically emerge at around four months of age. One or more paws of affected dogs become unable to feel pain. Affected dogs tend to lick or bite their paws excessively. The proprioception, motor abilities and spinal reflexes remain intact. And pain perception becomes progressively normal above the knees and is not altered in the rest of the body. The disorder can be suspected based on breed and typical clinical signs. The neurological status of affected dogs is normal except for their paws lacking sensory capacity.

There is no curative treatment for the disorder. Affected dogs are treated according to their condition and the severity of clinical signs. Affected dogs must be closely monitored so that infection and paw trauma can be spotted as early as possible. Self-mutilation must be avoided.

Quality of life concerns, lack of treatment options and the severity of this self-mutilation disorder usually leads to euthanasia on welfare grounds.

Reading

This very informative article and goes beyond just the symptoms etc, It also list some of the individual lab results.
And reminds us that no specific Cocker Spaniel research has yest taken place and caution is advised when including and relying on tests that could later become invalidated.

See Link below

Read about George the Cocker Spaniel who has Acral Mutilation Syndrome 

  • Acral Mutilation Syndrome
  • Acral Mutilation Syndrome
  • Acral Mutilation Syndrome
AMS
 Test With Caution
Mode of Inheritance
 *Autosomal Recessive
This is a heredity condition passed on from the parents.
Autosomal Recessive*  Tre are recent suggestion this may be  Autosomal Recessive with Incomplete Penetrance. Refer to articles from ECSCA Field Breed Working Cockers, and Paw Print Genetics.
Onset
 Juvenile
Clinical Symptoms dually develop from birth 0 to 2 yrs of age.
Testing Available
 DNA
DNA testing is available for this disorder through international Labs (It can not be done at your local vets).
Clinical Symptoms
* Excessive licking or biting of paws
* Affected puppies look smaller than healthy littermates

* Further complications such as infections, ulceration, nail loss, swollen paws and fractures are common

Breeding Strategy
 1 Clear Parent
To ensure progeny are not affected by this condition at least 1 parent must be clear.

AMS Around The World

Genetic testing has proven to be a invaluable tool and an intrinsic part of breeding healthy cockers and reducing the likelihood of disease.

Informal collection from RKC, Finnish, OFA & CSDB cocker spaniel databases
Data lasted updated September 2024

*AMS Testing to date has been undertaken mainly in working type cocker spaniels. Of the Total 11616 Dogs DNA Tested 2236 are show type and 9380 working type
. This is now part of the RKC testing requirements so I expect more data for show type cockers to become available.

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informal data collected from CSDB
Data lasted updated January 2025

% are more important when considering these statistics rather than the numbers recorded above, as some dogs results may have been duplicated in different databases

Found in 1 in 1,300 dogs in our testing
- Wisdom Panel

Research Notes on AMS

I do have concerns about making this mandatory test, until the mode of inheritance is definitively agreed upon. I would include it is Suggested but optional Although very few breeders cross Show & Working lines, it does happen, so we can't reply on this as a protective measure. At the very less is should be encouraged for Working Lines breeding/testing plans.

It has recently been discovered that this condition has multiple variants which effect different breeds. Research to date shows that Cocker Spaniels are effected by the GDNF-Type (Spaniel & Pointer Type)
AMS is a neurodegenerative disease that belongs to the group of disorders known as Hereditary Sensory Autonomic Neuropathies. The disorder causes insensitivity to pain and temperature and progressive self-mutilation of the distal extremities.

I have yet to research what this means for testing done prior to this GDNF Type development, but will add it here once it becomes available.

The Mutation of the GDNF gene associated with acral mutilation syndrome has been identified in Cocker Spaniels. Neither the frequency of the causal mutation nor its association with disease in cockers has been reported in the medical literature.

In addition, multiple apparently healthy cocker spaniels with two copies of the GDNF mutation have been identified by Paw Print Genetics. Thus, suggesting that this disease may display Incomplete Penetrance* and requires further specific cocker spaniel research

Note Orivet now includes this test as part of their full breed panel, so further information is being gathered which should prove a much better idea of its occurrence within the breed. However they do not publish their statistics, so we're still reliant on self reporting via CSDB and others.

Until that happens I will undertake the testing but be cautious with the results, until further objective data analysis defines the mode of inheritance by scientists.

There is a link below regarding my experience with using tests that are not fully proven or peer reviewed.