We all know that some animals are more prone to genetic or inherited conditions. But we tend to think more about dogs – so what about cats? What genetic conditions do we need to worry about in cats, and are any breeds more susceptible? Vet blogger Sarah Cooper investigates…

Table of contents

Genes and genetics

In order to understand genetic problems in any animal it’s probably worth first talking about what genes are, and how they can cause problems. In simple terms our genes are the sets of instructions that tell our cells how to make us. They contain the details of everything from eye colour to how we taste certain foods. Occasionally the instructions contain a mistake and, if serious, this can lead to problems known as genetic disorders.

These mistakes can either happen spontaneously or be passed on by either or both parents. We inherit our genes in sets of two – one from each parent. If only one parent passes on a faulty gene this can sometimes be overridden by the healthy version from the other parent, but not always. For some genetic disorders it is as simple as this – one faulty gene that causes a specific problem. Many other genetic and inherited diseases are more complex with lots of different genes involved in different ways and these can be much harder to figure out.

The problem with pedigree

Genes work the same way in our cats. We know that pedigree pets are significantly more likely to suffer from genetic problems than your average moggy. There are a few reasons for this. But it mainly comes down to the fact that when pedigree animals are bred, we deliberately select animals with certain characteristics or traits. Unfortunately, sometimes the traits that we deem desirable have deleterious effects on the animal. Or in other cases the genes for these desirable traits are linked to other faulty genes causing unexpected problems. This latter problem can be exacerbated when there are only a small number of individuals in a particular breeding pool. In these circumstances, closely related individuals are more likely to be bred together. This practice makes it more likely that both parents might pass on a faulty gene causing their offspring to suffer problems.

Certain breeds of cat are indeed more prone to genetic problems than others

If you are considering buying a pedigree cat then this is an important aspect to be aware of and research beforehand. For some genetic disorders caused by single faulty genes, genetic tests are available to identify “carriers”; these are animals that generally possess one faulty and one normal gene. These carrier animals are often either mildly affected or entirely unaffected by the faulty gene but run the risk of passing it to their offspring. Examples of these kinds of disorders include:

Testing for genetic disease

Genetic testing can also be useful to identify affected animals where the problem only manifests as they get older, past the age when they would be used for breeding. If the inherited problem is controlled by more than one gene, these tests are less helpful and spotting potential problems is more difficult. In these cases, it is important to research the health of both the dam and sire of a litter of kittens to look for any potential issues.

What about where we’ve bred for it?

It is also worth considering genetic traits that have been deliberately selected to make a cat look a certain way; but that can also impact negatively on their health. Examples of this include flattened faces in Persian cats that can cause issues with breath and eye problems; or hairless cats such as the Sphynx that can suffer from problems such as skin diseases, trouble regulating their body temperature and sunburn. 

Cats like the Scottish Fold are a good example of cats where a specific trait has been bred for looks but that has led directly to health problems. In this instance, the cartilage disorder that causes the desired folding of their ears also affects cartilage in other parts of the body such as their joints. This leads to the development of painful joints and arthritis at an early age. 

But possibly the most severe deliberate genetic abnormality is seen in the Munchkin breed. This breed has abnormally short limbs which prevent it from jumping and make it prone to painful arthritis. The gene that causes the problem is a dominant gene. This means that only one faulty gene is enough to cause the deformity of their legs and in fact kittens who inherit two copies of the faulty gene will generally die before birth

Disease Predispositions

There are also a whole host of diseases that are suspected to be linked to faulty genes but are likely to be more complex and linked to several different faults. These diseases tend to affect certain breeds of cats more commonly and include things like;

  • Diabetes mellitus in Burmese cats
  • Asthma in Siamese cats and other similar breeds
  • Patellar luxation in Abyssinian cats
  • Strabismus (squint) in Siamese cats
  • Hip dysplasia in Persian, Himalayan and Maine Coon cats

There are certainly some breeds that are over-represented in terms of genetic problems

These include Persians, Siamese, Birmans, Manx, Scottish Fold, Ragdolls, Sphynx and Bengals. If you are considering one of these breeds, research the problems they are prone to and whether there are any schemes that are run to try and reduce the incidence of disease. Speak to the breeder and ensure they are doing everything to minimise the chances of problems in their animals. Time researching the breed before you purchase a kitten is well spent and will hopefully help avoid the heartache of your precious pet developing a serious genetic disorder.

You might also be interested in: