Acral mutilation syndrome (AMS)

General description

Acral Mutilation Syndrome (AMS) is an inherited neurological disorder in dogs that causes a congenital loss of pain sensation in the limbs. Symptoms typically appear between 4 and 9 months of age and include repeated licking, biting, or self-injury to the paws and toes.

Breeds

English Cocker Spaniel, English Pointer, English Springer Spaniel, French Spaniel, German Short-haired Pointing Dog, German Spitz

Acral mutilation syndrome - English Cocker Spaniel, English Pointer, English Springer Spaniel, French Spaniel, German Shorthaired Pointer

In breeds such as German Shorthaired Pointer, English Pointer, English Cocker Spaniel, English Springer Spaniel, and French Spaniel, symptoms typically appear around four months of age, when puppies begin licking, biting, or injuring their paws and toes. Despite this, proprioception, motor function, and spinal reflexes remain unaffected. Some affected puppies only show pain insensitivity in the lower limbs without self-injury, making diagnosis more challenging.

Acral mutilation syndrome - German Spitz

In the German Spitz (especially the Pomeranian and Miniature Spitz varieties), AMS usually manifests between six and nine months of age. Early signs may seem mild—such as persistent licking of a paw—but can quickly progress to severe issues including lack of pain response in the distal limbs (paws and toes), chronic skin injuries, self-mutilation by chewing or biting affected areas, and even toe amputations (either spontaneous or surgical). In later stages, gait abnormalities (e.g., walking heel-first) and proprioceptive deficits may also develop.

The disease often worsens over time and can significantly impact the dog's quality of life. In some cases, progression may be slowed with protective measures such as collars or dog shoes.

In Spitz dogs, a genetic variant in the RETREG1 gene has been linked to AMS. This mutation leads to the degeneration of nerve cells, explaining the pain insensitivity and subsequent injuries.