Familial Nephropathy (FN) in the cocker spaniel

Familial nephropathy is a type of hereditary kidney disease that leads to renal failure in affected dogs, usually at a young age. It is relatively widely spread across the English cocker spaniel dog breed, with just over 10% of English cockers in the UK carrying the gene mutation that leads to the condition.

Generally, dogs affected with the condition will go into irreversible renal failure by the time that they reach the age of two, which cannot be cured and ultimately proves fatal.

Because the condition cannot be cured nor prevented other than by means of ensuring that the gene fault that causes familial nephropathy is not passed on to subsequent generations of dogs in the breed line, a DNA test has been devised to allow owners of English cocker spaniels to find out the status of their own dogs prior to breeding.

This allows breeders to make an informed decision on whether or not to breed from their dogs, and to find the right match for mating too.

In this article, we will look at familial nephropathy in dogs in more detail, including how the condition affects dogs, how it is inherited, and how to get your dog tested. Read on to learn more.

More about familial nephropathy

Familial nephropathy is a kidney disease that leads to early-onset renal failure, due to a hereditary defect in the glomerulus, which is a system that filters the blood that passes through the kidneys.

This defect occurs because the glomerulus is deficient in collagen (required to retain the structure of the filter), which in turn leads to proteins from the blood leaking into the dog’s urine. It also causes progressive damage to the kidneys themselves, and destroys the nephron structures of the kidneys too, which is irreversible.

Whilst the speed of the progression of the condition can be variable, it is generally faster than most cases of chronic kidney failure in dogs, and ultimately, proves fatal due to chronic renal failure.

Dogs affected by familial nephropathy usually go into renal failure while still very young, sometimes at the age of around six months, and the condition rarely presents for the first time in dogs older than the age of two.

The symptoms of the condition in affected dogs are the same as those caused by any other form of renal failure, including an unquenchable thirst, persistent need to urinate, loss of appetite and condition, and a general failure to thrive. Ultimately, the condition is fatal, and the decision may be made to euthanize the affected dog before the condition reaches this stage and so, end their potential suffering.

What sort of dogs can be affected by the condition?

Familial nephropathy in the UK is found in the English cocker spaniel breed, and around 10% of all dogs of the breed registered in the UK are carriers for the condition, which indicates that the gene mutation responsible for the condition is fairly widely spread within the breed’s gene pool in the UK.

This means that any English cocker spaniel (and cross-breeds that have some ancestry from the breed) may potentially be a carrier for the condition, even if they are not affected by the condition themselves.

How does the heredity of the condition work?

Familial nephropathy in dogs is an autosomal recessive condition, which means that different inherited combinations of the gene that leads to the condition result in different incidence rates of the condition occurring in the puppies produced by any mating.

• If both parent dogs are clear of the condition, their offspring will neither inherit the condition nor become carriers for it.
• If the two parent dogs are both affected by the condition, any offspring that they produce will be affected too.
• Breeding one affected dog with a carrier of the condition will result in a 50% chance for each pup to be either a carrier or affected.
• Breeding one affected dog and one clear dog will lead to their litter becoming carriers.
• Breeding two dogs that both carry the condition gives odds of 50% for each pup being a carrier, 25% chance of being clear, and 25% chance of being affected.

How can you get your dog tested?

If you own an English cocker spaniel and want to breed from them, it is really important to have them tested for their status first, as well as checking the results of their potential mate in order to make a well informed decision on whether or not to breed.

A simple DNA test is all that is needed to return as result on the dog’s status, and in order to request the DNA test, you will need to ask your vet to take a buccal sample (cheek swab) from your dog, which can then be sent off to one of The Kennel Club’s approved laboratories to return your result.

For information on the laboratories that can perform the condition, check out this list on The Kennel Club’s website.