Genetics Breeding practices harm the health of German Shepherds
The German Shepherd Dog suffers from the consequences of its popularity. A new study shows how inbreeding, wartime shortages and a focus on external ideals have made the once robust breed increasingly susceptible to disease.
24.11.2025, 21:00
SDA
For the study published on Monday in the journal "Proceedings" of the US Academy of Sciences ("Pnas"), an international research team analyzed historical DNA of German shepherds from 120 years ago. Some of the shepherd dog genomes studied came from the Natural History Museum in Bern.
Today, the gene pool of shepherd dogs is considerably smaller than it was 100 years ago. This genetic impoverishment makes the breed more susceptible to a number of health problems. These include joint diseases, painful movement restrictions, diseases of the nervous system as well as heart and blood diseases.
It was already known that many modern German Shepherds have health problems. However, it was previously unclear when and why these genetic deteriorations began and how historical events and breeding practices influenced this development.
One of the key findings of the study is that shepherd dog populations declined dramatically during and after the Second World War. The genetic analyses showed that after the war, breeding was concentrated on a reduced number of animals, which led to increased inbreeding.
Ideals of beauty
The genetic impoverishment of the dogs was exacerbated by the fact that certain breeding males, which were considered particularly successful due to their physical characteristics or their performance in breeding competitions, were used excessively often. This led to their genes being spread disproportionately. Not only were the desired traits such as body shape and gait passed on, but also harmful genes.
Another decisive factor in the genetic deterioration of German shepherds was the increasing emphasis on aesthetic ideals in breeding. While the breed was originally bred for working ability, over the course of the 20th century the focus shifted more and more to physical characteristics that corresponded to the breeders' ideals of beauty, according to the study.
