Hereditary Nasal Parakeratosis (Discovered in the Greyhound)

Hereditary nasal parakeratosis (HNPK) is a disorder causing crusting and dryness of the nose, leading to soreness and irritation.

Key Signs

Crusts, Cracking, Dryness of nose

Age of Onset

0 to 2 yrs

Juvenile onset


Autosomal Recessive

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.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with HNPK

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.

For Veterinarians

Here’s what a vet needs to know about HNPK

Clinical signs of the disease typically emerge at 6-12 months of age as dry, rough crusts develop on the nose. Dryness of the nose can lead to crack formation. These painful, bloody cracks can cause chronic irritation and inflammation of the nose. Depigmentation of the nose occurs over time and the nose changes from dark to a lighter color.

Supportive treatment based on the dog's specific clinical signs is recommended and often involves moisturizing agents.

For Breeders

Planning to breed a dog with this genetic variant?

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 HNPK mutation can be safely bred with a clear dog with no copies of the HNPK mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the HNPK 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 HNPK mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene SUV39H2
Variant Deletion
Chromosome 2
Coordinate Start 21,731,812
Coordinate End 21,731,815

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Bauer, A., Nimmo, J., Newman, R., Brunner, M., Welle, M. M., Jagannathan, V., & Leeb, T. (2018). A splice site variant in the SUV39H2 gene in Greyhounds with nasal parakeratosis. Animal Genetics, 49(2), 137–140. View the article