From the 15th of January 2018, a DNA test for Lethal Acrodermatits in Bull Terriers and Miniature Bull Terriers
Puppies Affected by Lethal Acrodermatits (LAD) have characteristic skin lesions and fail to thrive. These lesion consist of Erythema and adherent scales, primary on the feet, elbows, hocks and muzzle. Hyperkeratosis of the foot pads also occurs.
Dogs with LAD are also immunodeficient, so frequently suffering from skin infections such as Malassezia or Candida.
Puppies suffering from this condition have a greatly reduced lifespan either due to infections or they are euthanized when the condition becomes very severe and painful.
How is the disease inherited?
The Lethal Acrodermatits mutation is recessive; this means that a dog must inherit 2 copies of the mutation, one from each parent, to be clinically affected by Lethal Acrodermatits.
Individuals with one copy of the defective gene and one copy of the normal gene, called carriers, show no signs of disease but can pass the defective gene onto their offspring.
It is only possible to identify carriers with DNA testing.
When two carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will themselves be carriers.
Breeders using our DNA test will be sent results identifying their dog as belonging to one of three categories. In all cases the terms ‘normal’ and ‘mutation’ refer to the position in the DNA where this Lethal Acrodermatits mutation is located in the Bull Terrier and Miniature Bull Terrier; it is not possible to learn anything about any other region of DNA from this test.
What does the DNA test tell me?
The DNA test for Lethal Acrodermatits identifies if your dog is clear of the mutation, a carrier of the mutation or is affected by the mutation.
This allows breeders to avoid producing litters affected by this disease by ensuring that one of the breeding pair is clear of this mutation. This test can also be used to confirm a diagnosis of Lethal Acrodermatits.
CLEAR: These dogs have two copies of the normal gene and will not develop Lethal Acrodermatits as a result of the Lethal Acrodermatits mutation we are testing for, although we cannot exclude the possibility they might develop a similar condition due to other causes or the effect of other, unidentified mutations
CARRIER: These dogs have one copy of the mutation and one normal copy of DNA. These dogs will not develop Lethal Acrodermatits themselves as a result of the Lethal Acrodermatits mutation but they will pass the mutation on to approximately 50% of their offspring.
AFFECTED: These dogs have two copies of the Lethal Acrodermatits mutation and will have Lethal Acrodermatits caused by this mutation.
We cannot exclude the possibility that carriers might develop a similar condition due to other mutations they might carry that are not detected by this test.
We recommend that for the first few generations after the development of a DNA test you still breed with carriers to avoid reducing genetic diversity.
Dogs carrying this mutation can be breed from safely to avoid producing affected puppies. Carriers of the mutation should be mated to dogs that have a clear result; such a mating will not produce any puppies affected with Lethal Acrodermatits
On average, 50% of such a litter will be clear and 50% carriers; there can be no affected dogs produced from such a mating. Please note the distribution will vary from litter to litter.
Pups which will be used for breeding can themselves be DNA tested to determine whether they are clear or carriers of Lethal Acrodermatits.