This distressing condition has been appearing in the working lines of Cocker Spaniels. Affected dogs normally require euthanasia. The gene is autosomal-recessive (two parent carriers will produce a proportion of the offspring with the disease and a proportion will be carriers).
All members of the Cocker Spaniel Club undertake to abide by its Code of Ethics. Please be reminded of number 15 of the CSC Code of Ethics to be found on the Cocker Spaniel club web site.

'No owner should use for breeding a dog or bitch that has produced a confirmed and recognised hereditary disease with the following exceptions: Where DNA tests are available for such diseases, dogs or bitches that have been tested and proved positive to be carriers should only be bred to mates that are DNA tested Normal/Clear to avoid breeding affected puppies.'

To help avoid the spread of this disease The CSC Field Trial Section advise that you consider having your dog/bitch tested for AMS before breeding to ensure you are not breeding a carrier with a carrier. A simple test is available here:

http://www.antagene.com/en/ams-acral-mutilation-syndrome-english-cocker-spaniel