Hereditary nephritis or Samoyed hereditary glomerulopathy health testing

Hereditary nephritis, also known as Samoyed hereditary glomerulopathy, is a dominant hereditary health condition that can be found in the gene pool of some dogs of the Samoyed breed.

The condition is caused by a gene mutation on the X chromosome, and usually leads to eventual renal failure in affected male dogs, which almost invariably proves fatal. Whilst various other dog breeds can also suffer from a hereditary predisposition to renal failure and associated conditions, the Samoyed is currently the only breed that is prone to the condition’s fast onset and high fatality rate.

The condition cannot be cured or reversed in dogs suffering from Samoyed hereditary glomerulopathy, and the only way to prevent a dog of the breed from developing the condition is to ensure that they do not inherit the mutated gene that causes the condition from one of their parents.

A health testing protocol is in place for dogs of the Samoyed breed to enable breeders to find out their own dogs’ status and so, make an informed decision on viable mating matches, which helps to breed this genetic flaw out of the wider gene pool, and protect the future health of the breed in perpetuity.

In this article, we will look at hereditary nephritis or Samoyed hereditary glomerulopathy in dogs in more detail, including how the condition affects dogs, how it is inherited, and how to get your own dog tested. Read on to learn more.

What is Samoyed hereditary glomerulopathy?

Samoyed hereditary glomerulopathy is a hereditary health condition that usually begins to develop early on in affected dogs, with symptoms usually first becoming apparent by the time the dog in question is three to four months old, although the onset can be older in some cases. The first symptom of the condition is proteinuria, or excessively high levels of protein in the dog’s urine, which occurs because of a disease or fault in the glomerulus, or a set of capillaries in the kidney. This can make the dog’s urine appear to be foamy, which is often the first indication for owners that something is amiss.

Samoyed hereditary glomerulopathy is a progressive condition that in male dogs, leads to eventual kidney failure, and the death of the dog. In older dogs, Samoyed hereditary glomerulopathy tends to be faster in onset, and affected dogs rarely live past the age of around 18 months.

What sort of dogs are at risk of the condition?

Samoyed hereditary glomerulopathy poses a risk to dogs of the Samoyed breed, and first becomes apparent in juvenile and young adult dogs. Due to the mode of inheritance for the condition, males tend to suffer from a more acute and faster developing form of the condition than females, although both sexes can and do inherit the condition.

However, in female Samoyeds, the condition does not progress past the proteinuria stage, and so, affected female dogs do not go on to suffer from kidney failure as a result of the condition.

Mixed and cross-breed dogs with just one Samoyed parent are also at potential risk of the condition, because the gene mutation that causes Samoyed hereditary glomerulopathy is a dominant one, which means that any given dog need only inherit one copy of the faulty gene (from one parent) to inherit the condition.

How is the condition passed from dog to dog?

Samoyed hereditary glomerulopathy can only be contracted by inheritance, and the gene mutation that causes it is an autosomal dominant one, meaning that for a dog to be affected, they only need one affected parent and not two. Whilst Samoyed hereditary glomerulopathy is generally fatal in male dogs prior to the age of two – which greatly reduces the chances of male dogs unwittingly being used for breeding – females do not progress to the renal failure stage of the condition, and so might still be bred from and so, pass the condition on.

Samoyed hereditary glomerulopathy is transmitted by means of a dominant gene mutation, which means that only one affected parent can cause an affected litter. The mode of heredity for the condition is as follows:

• An affected dog and a clear bitch will produce a litter of clear males and affected females.
• A clear dog and a heterozygous affected bitch will produce a litter of 50% clear and 50% affected pups, regardless of the sex of the puppies.
• A clear dog and a homozygous affected bitch will produce a litter of affected pups, regardless of the sex of the puppies.

Health testing for Samoyed hereditary glomerulopathy

Finding out the status of any dog or bitch prior to breeding is something that can only be determined by DNA testing, and knowing a potential parent dog’s status allows breeders to reliably predict the status of their subsequent litter.

To get your dog DNA tested, you will need to ask your vet to take a blood sample or cheek swab from your dog, which is then sent away for laboratory testing to determine if the gene mutation that causes the condition is present, and how it is likely to impact on a dog’s future offspring.

Breeding and buying healthy Samoyeds

The dominant nature of the gene mutation that causes Samoyed hereditary glomerulopathy means that the condition spreads easily through breeding affected dogs, and the only way to ensure that any given mating match is a healthy one is to have both dogs tested prior to breeding.

Samoyed breeders should have both their dam and sire tested and remove affected dogs from the breeding stock, and potential Samoyed puppy buyers should ask breeders about their health testing protocols and request results before committing to a purchase.