Hereditary Nasal Parakeratosis (HNPK)

Quick Summary

Hereditary nasal parakeratosis is an inherited, recessive genetic defect that affects specialized cells of the canine nose, resulting in the formation of a crust with cracks over the nasal area of young dogs.

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Phenotype: Hereditary nasal parakeratosis affects specialized cells of the nose, resulting in the formation of a crust with cracks over the nasal area of young dogs. Affected dogs are otherwise healthy, although leaked fluid tends to accumulate in the cracks.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal, H = Hereditary nasal parakeratosis

Breeds appropriate for testing: Labrador Retriever, Labradoodle, Australian Labradoodle, other Labrador crosses

Explanation of Results:

  • Dogs with N/N genotype will not have hereditary nasal parakeratosis and cannot transmit this hereditary nasal parakeratosis variant to their offspring.
  • Dogs with N/H genotype will not have hereditary nasal parakeratosis, but are carriers. They will transmit this hereditary nasal parakeratosis variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% hereditary nasal parakeratosis-affected puppies.
  • Dogs with H/H genotype will have hereditary nasal parakeratosis and will transmit this hereditary nasal parakeratosis variant to all of their offspring.

Results of this test can be submitted to the OFA (Orthopedic Foundation for Animals)

Turnaround Time
At least 15 business days; may be delayed beyond 15 business days if sample requires additional testing, or a new sample is requested.
Price

$55 single test per animal ($5 discount on 3 or more dogs)

$25 as additional health test on same animal

Sample Collection

Dog DNA tests are carried out using cells brushed from your dog's cheeks and gums. The preferred cytology brushes are sent to you by mail, or you may provide your own brushes. For accepted alternative brushes, click here

We recommend waiting until puppies are at least three weeks old before testing.

 

Dog having its cheeks and gums brushed for DNA samples
Cheek and gum brushing technique for canine DNA sample collection

Step-By-Step:

  1. Make sure the dog has not had anything to eat or drink for at least 1 hour prior to collecting sample.
  2. When swabbing puppies, isolate each puppy from the mother, littermates and any shared toys for 1 hour prior to swabbing. Puppies should not have nursed or eaten for 1 hour prior to collecting sample.
  3. If collecting samples from more than one dog, make sure to sample one dog at a time and wash your hands before swabbing another dog.
  4. Label brush sleeve with name or ID of dog to be sampled.
  5. Open brush sleeve by arrow and remove one brush by its handle.
  6. Place bristle head between the dog’s gums and cheek and press lightly on the outside of the cheek while rubbing or rotating the brush back and forth for 15 seconds.
  7. Wave the brush in the air for 20 seconds to air dry.
  8. Insert brush back into sleeve.
  9. Repeat steps 5 - 8 for each unused brush in sleeve on a fresh area of cheek and gums. Make sure to use and return all brushes sent by the VGL. In most cases, it will be 3 brushes per dog. If using interdental gum brushes, please note that the VGL requires 4 brushes per dog and only moderate or wide interdental gum brushes are accepted.
  10. Do not seal brushes in sleeve.
  11. Place all samples in an envelope and return to the address provided.

ATTENTION:

  • Do not collect saliva/drool – the key to obtaining a good sample is getting cheek cells on the swab
  • Do not rub swab on the dog’s tongue or teeth – this will result in poor quality sample
  • Do not collect a sample from a puppy that has recently nursed – the mother’s genetic material can rub off on the puppy’s mouth and contaminate the sample
Additional Details

Hereditary nasal parakeratosis (HNPK) is a genetic defect caused by a mutation in a gene that regulates differentiation of nose skin cells. The mutation affects specialized cells of the nose resulting in the formation of a crust with cracks over the nasal area of young dogs. Affected dogs are otherwise healthy, although leaked fluid tends to accumulate in the cracks.



HNPK is inherited in an autosomal recessive fashion with males and females being equally affected. Dogs with one normal and one affected gene (carriers) show no signs of the disease. Carrier dogs will pass on the affected gene to 50% of their offspring.

Genetic testing for the HNPK mutation is recommended for Labrador Retrievers. Labradoodles and other crosses with Labrador Retriever content may also be at risk. The test assists veterinarians with diagnosis of HNPK and helps breeders to identify carriers to avoid breeding these together. Mating of carriers is expected to produce 25% of affected puppies.