Dogs can help us understand human diseases

What can be learned about human diseases by studying dogs?

Dogs share a large extent of the same genes and diseases as humans. By researching dog diseases, we can better understand corresponding diseases in humans.

In our research, we have used dogs as a model to understand diseases such as idiopathic epilepsy, eye diseases, heart diseases, anxiety, developmental disorders, and neurological diseases. Several rare diseases in dogs and humans are very similar, both clinically and genetically. Genetic discoveries in dogs provide an opportunity to understand the underlying disease mechanism. This opens up possibilities for developing diagnostics and better treatments for humans as well.

One example is that in a recently published study, we described two new candidate genes for heart muscle enlargement in dogs. Changes in the same genes were also found in human patients, which can explain their symptoms.

Why is the dog a relevant model for understanding diseases in humans?

One reason why the dog is an excellent model for research to understand human diseases is that the diseases occur naturally in dogs and develop in a similar way in humans. If mice were used as test animals, the diseases would have to be artificially created in the mice in laboratories. Additionally, dogs are larger and live longer than mice and rats, which means that a dog's physiology better corresponds to that of humans. Dogs are also exposed to the same environmental factors as humans because they live together.

Research is facilitated by the systematic breeding of dog breeds. Why does this make research easier?

For centuries, humans have bred hundreds of different dog breeds with specific behaviors and characteristics. Each breed has a number of genes that determine the breed's traits, and these selected gene variants have become common. At the same time, genes for genetic diseases have also been accumulated in the breed, even if unintentionally. Because the genomes of different breeds vary greatly and each breed has a limited population, it is easier to research dog diseases. All individuals within a breed are genetically very similar to each other. This low genetic variation makes dogs less complicated to study genetically than humans.

Where you would need to study 100,000 humans, it may be enough with 100 or 1,000 dogs.