One of the many things dogs share with humans (and with other multicellular beings) is having DNA to store their information.
Another thing they share with us (and again with other multicellular beings) is that this DNA can be passed from parents to offspring with anomalies. Genes with pathogenic sequences, which do not function correctly or do not function at all, can cause problems in the individual.
In other words, they have in common with us the ability to suffer from hereditary diseases.
The numbers are not insignificant. It is estimated that there are approximately 900 hereditary or genetically predisposed diseases in dogs. There are more, but those are the ones we have cataloged.
Another thing they have in common with us is that, among their diseases, some occur very exceptionally, and others are seen by veterinarians every week. Well, humans are not seen by veterinarians, but you get the comparison.
Common Genetic Diseases in Dogs
Among the most common hereditary genetic diseases, we can mention:
Skin allergies. It is considered that 10-30% of dogs have some form of skin allergy, varying in severity. In Golden and Labrador Retrievers, heritability is responsible for 47% of this allergy.
Hip dysplasia. This is the most common hereditary musculoskeletal disease in dogs. 14.6% of dogs that have undergone X-rays, regardless of the reason, showed hip dysplasia. It is common in large breeds, not only because of its frequency but also because small dogs with this condition do not show the same discomfort and suffer less pain.
Brachycephalic airway obstructive syndrome. This syndrome occurs in brachycephalic dogs. What did you expect it to arise in? Greyhounds? Brachycephalic dog breeds are those with a characteristic short muzzle, like the English Bulldog. Their abnormal craniofacial conformation causes an obstruction of the airways. The air enters the lungs as it can, not as it wants.
Patellar luxation. If you know how the patella works in any mammal, you know how it works in a dog. This small bone is located at the front of the knee and sometimes decides to leave its socket, causing numerous problems. Well, genes can make this happen more or less often. Unlike dysplasia, this occurs more in small breeds.
Hereditary cancers. Currently, cancer is the leading cause of death in dogs. While cancer cannot be inherited, the animal can inherit a predisposition to develop the disease over its lifetime.
Hypothyroidism. Another disease we share with them. And the most common hormonal disease in dogs, with 0.2-0.8% of them being affected. The symptoms are similar to those in humans: coat problems, weight gain with the same diet, increased exhaustion during exercise…
Cataracts. Again, a classic pathology in humans. There is no cure for canine cataracts other than surgery, with extraction and replacement of the lens. It is a normal disease as the animal ages, but there is a genetic component.
We Don’t Know as Much About Their Genetic Diseases
One thing dogs do not have in common with us is the tracking and recording of their diseases. There are no central canine hospitals where each case is noted and kept, making it impossible to accurately state the predisposition of each breed to each disease.
It may happen that less common breeds seem much healthier genetically than others. In these cases, one explanation is that, as breeds with few studied individuals, many of their hereditary pathologies have not been recorded due to a lack of study subjects.
That’s why so much is known about the diseases a Labrador Retriever can suffer from, but a Czech Terrier is more mysterious (additional note, it is a beautiful breed).
In 2023, the largest study to date was conducted with dogs. The study looked at 250 genetic diseases in more than a million dogs, finding that at least 57% of the animals studied are carriers of at least one copy of a pathogenic variant involved in a hereditary disease.
The study also found that the most common variants associated with diseases were shared between purebred and mixed-breed dogs.
Importantly, they were talking about the most common variants here. The frequency and predisposition to genetic diseases, in general, have a justified reputation of being higher in purebred dogs than in mixed breeds. With nuances.
A study from the University of California found 10 hereditary diseases that were more frequent in purebred dogs. For those who are curious, the diseases were aortic stenosis, atopy/allergic dermatitis, gastric dilatation-volvulus (GDV), early-onset cataracts, dilated cardiomyopathy, elbow dysplasia, epilepsy, hypothyroidism, intervertebral disc disease (IVDD), and hepatic portosystemic shunt.
Why the nuances? Because this phenomenon did not occur in all purebred dogs. Allergic dermatitis, hypothyroidism, and IVDD did show a higher prevalence in most purebred dogs compared to mixed breeds. Most, but for example, purebred terriers suffered fewer cases of IVDD than mixed-breed dogs.
The conclusion is that the prevalence of genetic diseases is more closely linked to the breed of the dog than to its purity. This does not exclude that being a purebred dog in specific pathologies is a risk factor, compared to a dog of that breed being mixed-breed.
Many of these genetic pathologies have been accompanying dogs since their common ancestors, some from thousands of years ago.
Prevention of Hereditary Diseases in Dogs
“Oh, no! How can I easily and quickly find out if my dog suffers from any of these hereditary diseases?”
You’re going to be very surprised coming from us, but the first method we recommend are genetic tests for dogs in general, and ours in particular. The symptoms will depend greatly on the disease.
A dog beginning to develop hip dysplasia will move less and with difficulty, while one with skin allergies will scratch excessively and show areas with greater hair loss.
One advantage of hereditary diseases is that they are hereditary. That is, they are inherited diseases. By knowing the clinical history of our dog’s ancestors, we can find out if there are genetic pathologies that have been previously expressed and may arise in our pet.
Depending on the disease, there are other methods to detect it. Hip dysplasia can be confirmed by X-ray, while skin allergy may require a blood test.
When in doubt, if we have the disease in our test, we recommend a Koko genetic test.