What factors contribute to hereditary health problems in dogs?

Hereditary health problems are those that have a genetic element to them, and hereditary means “inherited,” so a dog with hereditary health problems can be said to have inherited them from their ancestry. This does not necessarily mean that their parents themselves were unhealthy or had a health problem, and some hereditary conditions can be present further back in the breed line, and skip one or more generations. Some dogs can be a carrier for certain conditions too, without ever suffering from the condition in question themselves.

If you are looking to buy a dog or a puppy, or if you are a breeder, it is a good idea to have a basic understanding of hereditary health problems in general, and particularly, the factors that can contribute to them developing, or prevent them from occurring.

In this article, we will look at the main factors that can either raise or reduce the risk of any given dog having hereditary health problems.

Hybrid vigour

A dog that is of a mixed breed is exponentially less likely to suffer from hereditary health problems than a pedigree of any type, due to something known as hybrid vigour. Hybrid vigour is achieved by widening the gene pool of an animal by outcrossing it to totally unrelated animals, and in the case of dogs, this means dogs of different breeds, as dogs of the same breed will of course be related, albeit often very distantly, somewhere down the line.

Inbreeding

Pedigree dog breeds all arose in the first place, and survive in perpetuity, by limiting the gene pool of the breed to only other dogs from the same breed. This in its turn both guarantee’s the breed’s specific recognisable and desirable traits, but also, increases the risk of hereditary health problems.

Within some pedigree breeds that are very populous, the inbreeding required to produce the line is very low, and plenty of available dogs for breeding mean that the breed will tend to be robust and healthy. However, for some breeds with a very limited gene pool, or in the case of deliberate inbreeding to produce a desirable breed line, the chances of hereditary health problems developing is much higher.

Breeders use an equation called the coefficient of inbreeding to calculate the level of inbreeding within their lines. A coefficient of 6.25% or less is considered to be the ideal for pedigree breeds, and any figure above this may place the breed at higher risk of hereditary health problems becoming prevalent.

Conformation problems

What makes a breed a breed is the recognised uniformity across all of its dogs, such as a similar build, appearance, shape, and other factors such as temperament. This means that dogs that conform most closely to the breed standard of desirable traits are those most likely to be bred from, and some of these desirable traits themselves come with risks.

Conformation problems such as hip dysplasia or overly large heads can all lead to problems developing in subsequent litters; the chances of developing hip dysplasia, for instance, is calculated by working out the hip score of the parent dogs by testing. A higher hip score means a higher chance of hip problems being passed down the line.

Dogs with flat, brachycephalic faces such as the pug are also exponentially more likely to suffer from breathing problems, and issues keeping cool in hot weather.

Health testing

A huge range of different health tests can be performed on dogs, to identify anything from the condition of their hips to a propensity to problems with their eyes or major organs such as the heart. In a great many cases, performing health tests on potential parent dogs can give the breeder an informed insight into the health of their potential litter, allowing them to make a decision on whether or not to breed, or which two dogs to match.

Many breeds that have a known predisposition to certain hereditary health problems have a range of tests recommended prior to breeding, and if you are looking to buy a dog, it is wise to find out what hereditary health conditions are recognised within the breed, find out if the parent dogs were tested, and ask to examine the results.

Lifestyle

The lifestyle of any given dog can have a huge impact on their health, and whether or not any potential hereditary health problem is likely to develop or worsen. Factors such as diet and exercise can help keep your dog’s weight under control, which can in turn help to avoid or minimise certain problems.

Feeding a diet that is designed to help tackle known or suspected problems can also prevent or minimise the effects of some conditions, such as skin problems or dietary intolerances.

Taking care of your dog in the right way that is appropriate for them at every stage of their life can help to keep them healthy, and reduce the occurrence rate of potential problems.