Ichthyosis is a condition characterized by scaley skin and dandruff. It does not cause itching, scabbing, or hot spots and it is not the same thing as allergies. In Golden Retrievers, it is usually very mild, though in other breeds it can be much more severe. The Golden Retriever Club of America says that it is a rare condition even though a high percentage of dogs are testing positive for it. A few breeders are making a big deal out of it. Most don't test for it at all. We, along with a growing number of other breeders are taking a middle of the road approach. We do the test and use the results in making good breeding decisions. At the same time, we feel that this is a minor issue and that there are many other concerns that are more important.
What is Ichthyosis and How Does It Affect a Dog?
Ichthyosis is doggy dandruff. When a dog has symptoms, those symptoms are usually a light flaking of skin. There can, however, be a wide range of possibilities with regard to the severity of the condition. Many (I would venture to say most) dogs that receive DNA results that indicate that they are
affected with Ichthyosis have no flakes or any other kind of skin problem. Some dogs with Ichthyosis have a light flaking of skin, most noticable when brushing. It does happen at times, however, that Ichthyosis is bad enough for there to be a constant flaking of skin. Even then, it is more of a nuisance to the owner than a bother to the dog. A severe case could cause a dog to leave flakes of skin wherever he sits or lies. These cases are not common. By far, the majority of Golden cases are very mild.
Ichthyosis is not anything like allergies that many Golden Retrievers suffer from. Ichthyosis very rarely bothers a dog. It doesn't cause itching or scabbing like allergies. Ichthyosis in Golden Retrievers whether in its mildest form or its most severe is simply dandruff or flaky skin.
The condition isn’t curable, but is usually well controlled with brushing, mild shampoos and conditioners, and a diet high in fatty acids. I have heard of several affected dogs who had flakes to totally disappear after just a change in diet. I personally believe that the dog food that many people are feeding is causing a whole host of problems in American dogs including the expression of Ichthyosis. The marketing strategies of the big dog food companies have convinced much of the American public (and even many vets) that food cheaply made with little meat, lots of grains, preservatives, and chemicals is what dogs thrive on.
What is the Significance of the New DNA Test?
Ichthyosis is a recessive trait which means that both parents have to carry the Ichthyosis form of this particular gene for there to be any possibility of any of the puppies to be affected with the condition. If either parent is clear, there is no chance of any puppies being affected. There are three possible results of the DNA test,
clear. If both parents are carriers, 25% of the puppies will be affected (not necessarily clinically, but will have a DNA test that says they are affected), 50% will be carriers, and 25% will be clear. If one parent is a carrier and the other is affected, 50% of the puppies will be DNA affected (again, this doesn't mean clinically affected). If both parents are DNA affected, all puppies will be DNA affected. A dog that is a carrier will have no chance of having the condition, either by DNA test or clinically. A carrier is simply a dog with only one copy of the defective allele for the gene. Two copies are needed for a dog to be DNA affected.
The statistics on the percentage of Goldens with Ichthyosis according to the DNA test would be quite disturbing if the statistics for the number of Goldens with actual symptoms matched those DNA statistics. There is, however, a huge difference between the two. The DNA statistics from Antigene, a testing company says that 30% of Goldens are
affected by Ichthyosis. However, the Golden Retriever Club of America says that Ichthyosis is rare and that less than 1% of all skin conditions in the breed are caused by Ichthyosis. Wow! What a difference in the statistics! 1% of dogs with skin disorders or 30% of all dogs. There are links at the bottom of this article to the GRCA and to Antigene where you can read these statistics for yourself. The difference between the 1% and the 30% represents those dogs who have no symptoms or with symptoms so mild that noone knows they are there.
Further information from Antegene says that 40% of Golden Retrievers are carriers and only 30% are clear. When the number of dogs that are either carriers or affected are broken down by the area of the world, 61% of Golden Retrievers in America are carriers, 52% in Australia are carriers, and 83% of Golden Retrievers in Europe are carriers. For English Golden Retriever breeders trying to have breedings clear of Ichthyosis, finding quality Goldens in the 17% that are clear of Ichthyosis is a challenge. To do this would undoubtedly reduce the gene pool tremendously and all for the sake of eliminating a condition that the Golden Retriever Club of America says is rare and mild, for a condition whose symptoms don't bother the dog, for a condition that is easily controlled by a healthy diet, regular brushing, and using mild shampoos (all things that we should be doing for our dogs anyway), for a condition that is responsible for less than 1% of all skin conditions in Golden Retrievers, and for a condition that many veterinarians have never heard of.
I have seen in talking to other breeders and in my reading that the dogs with clinical cases of Ichthyosis do tend to reproduce those symptoms and that dogs with a positive DNA test but with no symptoms tend to produce symptom-free puppies. I think keeping this fact in view is key in wisely using the DNA test. I believe the more prudent approach to breeding away from Ichthyosis is to breed unclear dogs in lines who have clinical cases of Ichthyosis only to clear dogs, to pursue a goal of eliminating the condition all together over 6 -8 generations, to use the DNA test in making good breeding decisions, to continue doing the test and using the results wisely, to be open and honest to the public about what you have, and to use good common sense about it realizing that there are other issues in our breed that need greater attention. If too much importance is focused on this mild skin condition, our breed would have 1% less skin problems but would be full of dogs with other health problems, poor temperaments, narrow unsightly heads, and poor conformations.
affected diagnosis does not always (or even usually) mean a dog has a skin problem, because Ichthyosis in Golden Retrievers is rarely a condition that affects the quality of life of the dog, and because there are so few English Goldens who have tested as clear, we at Summer Brook have decided to test for Ichthyosis and make that information available to potential buyers, to take Ichthyosis test results in consideration, but to make other issues a priority. Some of our litters will have a parent clear of Ichthyosis, but not necessarily all. Any litter that we breed without a parent clear of Ichthyosis will have backgrounds clear of clinical signs of Ichthyosis. If we find evidence of clinical signs in the lines, that dog will be paired only with a clear. So far, we've not had a dog with visible signs of Ichthyosis nor has anyone ever reported to us that any puppy we've produced had skin problems of any kind.
If you would like to do further reading on Ichthyosis in Golden Retrievers, click on any of the underlined links below.
Golden Retriever Club of America on Genetic Health (including Ichthyosis)
Antagene (the testing company)
Golden DNA (a website database of those dogs who have been tested and whose owners have sent in the required paperwork to have their dogs listed)