Acral Mutilation Syndrome

Acral Mutilation Syndrome (AMS) causes insensitivity to pain, leading to a tendency to lick or bite paws excessively. This often results in loss of toenails, fractures, and toe amputation.

Found in

1 in 1,300 dogs

in our testing

Key Signs

Excessive licking or biting of paws

Age of Onset

0 to 2 yrs

Juvenile onset


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with AMS

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about AMS

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. This self-mutilation is severe and often results in toenail loss, fractures, and digit amputation. The motor abilities and proprioception of affected dogs remain normal. It has been suspected that the trigger for paw biting and licking in these dogs are minor paw injuries caused by insensitivity to pain. 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. The disorder is severe and usually leads to euthanasia on welfare grounds.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to develop. A carrier dog with one copy of the AMS mutation can be safely bred with a clear dog with no copies of the AMS mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the AMS mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the AMS mutation could develop due to a different genetic or clinical cause.

Technical Details

Variant C>T
Chromosome 4
Coordinate 70,875,561

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Plassais, J., Lagoutte, L., Correard, S., Paradis, M., Guaguère, E., Hédan, B., … André, C. (2016). A Point Mutation in a lincRNA Upstream of GDNF Is Associated to a Canine Insensitivity to Pain: A Spontaneous Model for Human Sensory Neuropathies. PLoS Genetics, 12(12), 1–21. View the article