Overview
Adult-Onset Neuropathy (AON) is a progressive weakness that has been recognised by the research team at the University of Missouri Animal Molecular Genetic Lab as an autosomal recessive, hereditary disorder in English Cocker Spaniels and Field Spaniels.
Clinical signs typically begin between 7.5 and 9 years of age and progress gradually over 3 to 4 years. Initially signs consist of an uncoordinated gait or wobbling in the hind limbs. The stance in the hind limbs is wide-base and the hocks will drop lower to the ground. The weakness eventually progresses to also involve the front limbs. When dogs become non-ambulatory in all limbs, difficulty in swallowing also becomes apparent.
This test is based on the genetic variant that the researchers from the University of Missouri Animal Molecular Genetic Lab have identified as responsible for causing AON and we would like to thank them for sharing their research findings with us, so that we can offer this test to English Cocker and Field Spaniel breeders in the UK and Europe.
Please note that we are unable to sell this test to customers in the United States.
The variant that causes Adult-Onset Neuropathy (AON) in English Cocker Spaniels and Field Spaniels is autosomal recessive. This means that dogs that carry two copies of the mutation (homozygotes) are at risk for developing clinical symptoms of AON at some point in their lifetime, usually after 7 years of age. The clinical signs will progress slowly over 2-4 years, similar to degenerative myelopathy (DM), but the disease course is more gradual and of longer duration.
Dogs that carry a single copy of the mutation (also known as carriers or heterozygotes) will not develop AON as a result of this mutation, but they will pass the mutation onto about half of any offspring they have. Breeding dogs that will not develop AON should be the breeder’s priority, with a reduction in mutation frequency within the whole breed being the secondary, longer-term target.
Carriers can be bred from safely, provided they are mated to a dog that has also been tested and is clear of the AON mutation (i.e. carry no copies of the mutation). If a carrier is mated to a clear dog approximately half of the resulting puppies will also be carriers, so should be tested themselves prior to breeding. Breeding carriers to tested, clear dogs is safe, in terms of avoiding dogs affected with AON, and will help to maintain the genetic diversity of a breed. It is therefore encouraged, particularly in the first few generations following the availability of a new genetic test, so that other desirable characteristics and traits can be preserved before the frequency of the disease mutation within the breed is gradually reduced.
