Ichthyosis (ICH or ICT) in Golden Retrievers

We received Maxine's DNA test results back from Embark, and it turns out she is a "carrier" for Ichthyosis-A (commonly referred to as ICH, ICT, ICT-A, or ICH-A). With that in mind, a bit of explanation is needed.

Let’s address the key points first. Being a carrier for ICH is relatively common and completely harmless for your pet, with no symptoms whatsoever. It only becomes a concern if you plan to use the dog as a breeder. As I’ll explain below, it is entirely harmless as long as your breeder (and we hope you choose us) pays attention to the genetics of the dog’s breeding partner.

I’ll be using three terms throughout this explanation, and it’s important that you understand their meanings:

Carrier = no symptoms presented due to the mutation – ever
Affected = will experience symptoms
Clear = no mutated ICH gene

What is Ichthyosis (ICH)?

Ichthyosis-A is a genetic variant that primarily affects Golden Retrievers, as well as a few other dog breeds. It is an autosomal recessive genetic mutation that impacts the skin, preventing the outer layer of the epidermis from forming correctly. This leads to skin that becomes thick, darkened, and excessively flaky. While I considered including images, the internet is filled with worst-case scenario photos, and in reality, most cases are not severe. Therefore, I decided against presenting such alarming images.

It’s important to distinguish Ichthyosis from Seborrhea, which is simply dandruff. ICH is a genetic condition that, in some cases, can be much more severe than dandruff, but it is entirely preventable, as you will see below.

ICH is quite common in Golden Retrievers. While the exact percentage of Golden Retrievers carrying this mutation is not fully known, studies in Europe have shown that approximately 45% are carriers, and nearly 30% are affected. In the United States, the numbers may be lower due to different approaches to managing the condition, although I have no studies to back this up.

The term "Ichthyosis" comes from the Greek word for fish, due to the scale-like appearance of the skin in affected dogs. A common nickname for the condition is "Fish Scale Disease." The most common symptom is skin flaking, similar to human dandruff, though some affected dogs may also experience hardening and darkening of the skin. The severity of these symptoms can vary and may worsen or improve over time depending on factors like hormone levels and stress. Symptoms in an affected dog can appear at any age, but they are most commonly noticed before the dog’s first birthday. The only way to confirm ICH is through a simple, inexpensive DNA test, so flaky skin in a Golden Retriever does not necessarily mean they have ICH.

In general, ICH is not dangerous to a Golden Retriever’s health. While it is mostly a cosmetic issue, it can cause discomfort or itching. The symptoms can be managed to some extent with the right shampoos and treatments, but there is no cure.

Is it advisable to breed a Golden Retriever with ICH?

In most cases, it is completely safe to breed a Golden Retriever that is a carrier of ICH, as long as certain precautions are taken. In some rare instances, breeders may choose to breed an affected dog, but there must be a very good reason, typically for the improvement of breed conformation.

In Europe, it is relatively common for breeders to breed affected dogs, and many simply dismiss it as “dandruff.” In the United States, breeders tend to be more cautious about this issue, though it is still something that occurs.

How can breeders manage Ichthyosis?

The trick for preventing affected status is to know the DNA status of both breeding parents and only breed proper combinations. The following set of bullets outline how to determine how the ICH gene can be inherited based on the genes of both parents

Note: the % chances listed below are per puppy, not per litter.

Parents are Clear + Clear
- All puppies are clear
Parents are Clear + Affected
- All puppies are carriers
Parents are Carrier + Clear
- Puppies have a 50% chance of being a Carrier
- Puppies have a 50% chance of being Clear
Parents are Carrier + Carrier
- Puppies have a 25% chance of being Clear
- Puppies have a 50% chance of being a Carrier
- Puppies have a 25% chance of being Affected
Parents are Carrier + Affected
- Puppies have a 50% chance of being Carrier
- Puppies have a 50% chance of being Affected
Parents are Affected + Affected
- All puppies are affected

CONCLUSION

ICH-A is a completely manageable genetic mutation that is very common in Golden Retrievers. Since the American Kennel Club and European kennel clubs have not condemned it, Ichthyosis remains a thing. It is completely preventable with responsible breeding practices but unfortunately is still common. Ichthyosis is not deadly nor typically bad for the dog’s health but it can be uncomfortable and can detract from the good looks of the dog’s coat in some cases. If a Golden Retriever is a “Carrier”, there are absolutely no health risks nor symptoms. If breeding an ICH-A “carrier”, the breeder should simply insist the mate is tested and “Clear” of ICH-A. The puppies produced will have a 50% chance of being a carrier but that matters not at all if the puppies will be sold with limited registration never breed. Even if sold with full registration where breeding is probable, producing a puppy that is a “carrier” is not evil as long and breeders pays careful attention to it.

If you are concerned about ICH (and I believe you should be), it’s crucial to only purchase puppies from breeders who can provide DNA test results for BOTH parents. If both parents are “Clear,” you’re good to go. If one parent is a “Carrier” and the other is “Clear,” you’re still in the clear, as none of the puppies will be “affected.” However, if either parent is “affected,” you’ll need to be more cautious. In this case, I strongly recommend requesting a DNA test on the puppy to ensure it is not “affected” before making your purchase.