For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.
At risk dogs are highly likely to show signs of this disease in their lifetime.
Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.
Clinical signs of this disorder can be seen in puppies even before they are weaned. The coat of affected puppies is scruffy and the areas of skin without hair are reddish and have light brown scale, giving it a wrinkly appearance. The disorder persists through life and adult dogs have a reddish-brown discoloration across their abdomen, axilla, and inguinal regions and scaling is present throughout the body. Problems associated with this disorder include the possibly of severe Malassezia (yeast) overgrowth causing ear and skin infections. Differential diagnoses include primary seborrhea, sebaceous adenitis, and demodicosis. Scaling may be caused by a number of skin diseases such as allergic and hormonal diseases, parasite infestations of the skin, and infections.
Currently, no curative treatment exists for the disease. Treatment usually includes topical keratolytic agents, topical moisturizers, and topical antimicrobials. Treatment must be tailored to the individual's needs based on the degree of clinical signs and tapered down by clinical response. Sometimes oral antifungal therapy is required. Oral omega-3 and omega-6 supplementation may have some benefit.
There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.
This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to develop. A carrier dog with one copy of the Ichthyosis mutation can be safely bred with a clear dog with no copies of the Ichthyosis mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the Ichthyosis mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the Ichthyosis mutation could develop due to a different genetic or clinical cause.
All coordinates reference CanFam3.1
Casal, M. L., Wang, P., Mauldin, E. A., Lin, G., & Henthorn, P. S. (2017). A Defect in NIPAL4 Is associated with autosomal recessive congenital ichthyosis in American bulldogs. PLoS ONE, 12(1), 1–9. View the article