What is Lafora Disease?
Lafora Disease is an inherited form of epilepsy that affects Miniature Wirehaired Dachshunds.
Symptoms develop because the dog cannot efficiently process starch into sugar. Over time, insoluble starch platelets gradually build up in the central nervous system. Survey results indicate that the majority, if not all dogs, will go on to show clinical symptoms to a greater or lesser degree. It typically becomes apparent any time from age 5+ with a variety of symptoms including myoclonus (jerking, characteristically this can be induced by flashing lights, sudden sounds and movement, especially when close to the dog’s head) and/or generalised or complex partial seizures. As the disease progresses, other neurological symptoms such as ataxia, blindness and dementia may occur. (Videos & presentations here). Lafora dog videos on YouTube.
Genetics of Lafora
Lafora is an inherited autosomal recessive condition. A dog must inherit two of the mutated genes, one from each parent to be classified “Affected”. A dog that has only one mutated Lafora gene is a “Carrier”. It will not become clinically affected by the disease but, if bred to another “Carrier” or “Affected” dog, some of the puppies born will be likely to receive the two mutated genes and thus be clinically affected. If a dog carries no mutated genes it is “Clear”.
Testing for Lafora
In March 2013, a DNA test organised by the Wirehaired Dachshund Club was Kennel Club approved and ‘recommended’ for registered mini wires and ‘required’ for KC Assured Breeders. Samples were sent to same team at the Children’s Hospital in Toronto who originally identified similarities between the human and canine Lafora. In early 2019 Laboklin had a Lafora blood test approved by the KC and as a result the WHDC scheme finished. Test results are sent direct to the Kennel Club, where results will be added to the dog’s registration details, triggering publication of results in the next Breed Records Supplement, any new registration certificate, on certificates of any future progeny, and on the Kennel Club Health Test Results website.
Safe vs. unsafe breeding
Because the disease is “late onset”, the only way to avoid breeding “Affected” Mini Wires is to use the full DNA test to screen all breeding stock, prior to mating.
Dogs that are “Affected” by the disease, or are “Carriers” of the genetic mutation, are at risk of producing more “Affected” puppies if they are bred from with others carrying the mutation.
(N.B. “Unaffected” results are from an earlier test that could identify dogs that were NOT affected but may be either carriers or clear).
Owners of Stud Dogs
Stud dog owners have a responsibility to the breed to know not only the status of their own dog but also that of any bitches brought to them and refuse to mate any unsafe pairings, or better still, test your stud AND insist that you will only allow a mating with a tested bitch, as that will encourage others to test.
Owners of Breeding Bitches
Ensure you know the status of both your own dog and that of any prospective studs. Dogs should not be mated unless you can guarantee that no affected dogs will be born. Sadly, experience suggests that you cannot always take the word of the owner.
Dr Clare Rusbridge of the University of Surrey’s School of Veterinary Medicine and the Toronto Hospital team, supported by the Dachshund Breed Council, continue to monitor the progression of the condition in Lafora affected dogs. Details of their latest research was published in August 2017 in PLOS One.