Canine Testing
Canine Testing
We are now officially licensed by the Animal Health Trust to offer testing for the HSF4 gene mutation, the Hereditary Juvenile Cataract Mutation. This test detects the HSF4 mutation, which is responsible for hereditary juvenile cataracts in the Boston Terrier, Staffordshire Bull Terrier and French Bulldog. The cost of the test is $45. To request a toenail blood collection kit and submission form, contact Dr. Graves.
About Juvenile Cataracts in Dogs & the HSF4 Test
A mutation in the HSF4 gene has been shown to be associated with early onset cataracts in the Staffordshire Bull Terrier, Boston Terrier and French Bulldog (Mellersh et al. 2006, Mellersh et al. 2007). These cataracts are detectable as early as 12 weeks of age by an ophthalmologist or in some cases by routine eye exam. They result in blindness by 18 months of age. Please keep in mind that there are numerous forms of cataract in dogs and this test is specific only for the early onset juvenile cataract in the specified breeds. In the Boston Terrier, there is at least one other form of juvenile cataract that begins developing at 3‐5 years of age. This test does not detect that type of cataract.
Carriers of the HSF4 mutation do not exhibit any detrimental effect. If they develop cataracts at a later age, they are NOT due to this mutation. The HSF4 mutation is recessive and only causes cataracts when a dog inherits a mutated copy of the gene from each parent. Therefore, the following is true:
- If a dog tests CLEAR for the HSF4 mutation, it is not a carrier and cannot produce an affected offspring, even when bred to a CARRIER.
- If a dog tests as a CARRIER for the HSF4 mutation, it has one copy of the mutation and one normal gene. This dog will not develop cataracts due to this mutation. This dog CAN be used for breeding, but should not be bred to another CARRIER. If it is bred to another carrier, there is a 25% chance an affected puppy will be produced.
- If the dog tests AFFECTED, it has two copies of the mutated HSF4 gene, and this dog will have early onset juvenile cataracts. It should not be used for breeding.
Instructions for HSF4 Dog Cataract Testing
- Clean the foot so there is no contamination around nails.
- Slightly clip your dog's nail with nail clippers.
- Allow blood to collect into a small drop on the end of the nail.
- Take the FTA card and blot the drop of blood onto one of the four circles on the card until there is a blot the size of a dime (at least two circles need blood within the circle, so more than one nail may need to be collected).
- Allow the FTA card to air dry at room temperature (between 30 minutes to an hour).
- Fold cover back over circles with blood dried on the FTA card.
- Place the card in the envelope and send by regular mail to the lab using the pre-addressed envelope provided.
