From cure to prevention
Healthy breeding of cats and dogs
The Utrecht Expertise Centre for Genetics has a mission. The scientists do everything they can to prevent hereditary diseases and harmful physical traits in dogs and cats. They conduct groundbreaking research and translate the results into practical tools for veterinarians, breeders and policymakers. 鈥淪cientific developments in the field of genetics are fast-paced, and we understand hereditary diseases in dogs and cats much better,鈥 says Hille Fieten, director of the Expertise Centre of Genetics. 鈥淚 believe it is our moral duty to make use of this knowledge.鈥
Unfortunately, many purebred dogs and cats suffer from hereditary diseases or harmful physical traits. Veterinarians see the consequences almost daily in their clinics. Fortunately, a growing amount of data is becoming available. Researchers at the Expertise Centre for Genetics regularly publish new discoveries in collaboration with international colleagues. For example, they have found DNA markers that influence the risk of stomach cancer in Belgian Shepherds and new risk genes for DCM (dilated cardiomyopathy) in Dobermanns.
鈥淜nowledge on presence and frequency of hereditary diseases is invaluable鈥, says Fieten. 鈥淪he points to research on syringomyelia (SM) in Dutch and Danish Cavalier King Charles Spaniels by Paul Mandigers. 鈥淚t occurs in 39 to 46 per cent of the dogs. PhD student Citlalli Limpens has shown that this number would drastically decrease if breeders avoided using dogs with SM and only bred with dogs older than 3 years, as the disease manifests later in life. With this knowledge, prevention programs for these breeds can now be developed.鈥
Impact
Good cooperation is needed between researchers, breeders and veterinary practitioners to seize opportunities and make an impact. Sometimes, the government also has a role to play, especially when hereditary conditions are so severe that policymakers do not want to leave it to the sector alone. 鈥淭his was the case with brachycephalic dogs鈥, says Fieten. 鈥淭he minister asked our Expertise Centre to develop criteria for skull conformation based on scientific evidence and supported by veterinary specialists. The government has now implemented these criteria in law (see box). We are leading the way in the Netherlands, and the national government shares the experiences with other European Member States. I am proud of these steps as they will improve the lives of many brachycephalic dogs in the future.鈥
Another example of concrete impact is the development of the breeding program 鈥淔it2Breed鈥, which was first applied to the Kooikerhondje. 鈥淭here are about 15,000 Kooikerhondjes worldwide鈥, says Fieten. 鈥淎nd yes, population management has its challenges, especially regarding inbreeding and preventing hereditary diseases. We have been working with breeders of the Kooikerhondjes for a long time, and they are exceptionally supportive and transparent on the diseases that are present in the breed.鈥 Based on the information provided by the breed club, Peter Leegwater and Paul Mandigers have identified various DNA mutations that cause hereditary diseases in Kooikerhondjes, such as hereditary necrotising myelopathy and polymyositis. DNA tests have been made available for these diseases, allowing them to be effectively combated in the breed. 鈥淢oreover, we have brought all the data together in the Fit2Breed program. It offers wonderful possibilities.鈥 (see box)
PetScan
According to Fieten, there has been a real cultural shift among Kooikerhondje breeders, and this change is needed for more animal breeds. She sees a crucial role for veterinarians in this process. 鈥淰eterinarians can advise consumers and breeders. Moreover, as a profession, we can ensure that new information about hereditary diseases is collected and analysed. For this, we have developed special software called PetScan.鈥
The program is now available in more than 90% of veterinary practices in the Netherlands, as software suppliers of practice management systems strongly endorse the importance of a program like PetScan for the health of companion animals. Veterinarians can use PetScan for free to register diagnosed conditions, enabling nationwide monitoring of hereditary diseases. 鈥淭his way, we can have a wealth of information at our disposal鈥, says Fieten. 鈥淭hen what I call a true 鈥榗ycle of improvement鈥 arises: as a profession, together with consumers and breeders, we collect the necessary data. Scientists can analyse these data, providing education and advice based on evidence. This knowledge can then be applied with DNA tests and programs like Fit2Breed. The result: healthily bred companion animals. That is our goal.鈥
Breeding Ban for Extreme Brachycephaly
Brachycephaly (short-snoutedness) and breeding with short-snouted dogs often leads to severe welfare issues. For example, dogs can suffer from shortness of breath or damage to the eyes. To address this, the Expertise Centre for Genetics, commissioned by the Ministry of Agriculture, Fisheries, Food Safety and Nature, has prepared a report with six skull criteria for breeding brachycephalic dogs. The criteria include absence of respiratory sounds at rest, open nostrils, a craniofacial ratio (ratio between nose length and skull length) of more than 0.3, absence of a nose fold that touches the eye, minimal visibility of the eye white, and the possibility to completely close the eyelids.
In 2019, the ministry banned breeding with dogs that do not meet these criteria. In 2023, the temporary exception for breeding extremely short-snouted dogs with a longer-snouted dog also stopped. The then-minister called the new rule 鈥渁n important step鈥 in breeding healthy dogs. The Netherlands is also committed to raising awareness of the harmful traits among other EU Member States.
鈥淚 am very happy with the progress that we made鈥, says Fieten. At the same time, she believes further steps are needed in the Netherlands. 鈥淣ow, dogs still end up in the Netherlands through import because there is consumer demand for this type of dog. I think that we need to work towards a culture where we collectively no longer find it acceptable to buy a dog or cat with harmful physical traits.鈥
Watch a video on the application of the criteria by veterinarians.
Fit2Breed
Fit2Breed is a unique platform developed by the Expertise Centre for Genetics to prevent hereditary diseases in dogs and cats. In 2024, Fit2Breed became available for Kooikerhondje breeders. The program uses data from Kooikerhondje populations worldwide, including disease data, screening results, pedigree information, DNA test results and SNP markers. Based on this, a comprehensive population analysis was made.
Fit2Breed offers an interactive pedigree where users can see all dogs and identify common ancestors. The program also has a breeding module where test matings can be performed, providing breeders with a risk assessment for the offspring based on disease data and inbreeding. Additionally, Fit2Breed advises on which males to use, prioritising those that are genetically or pedigree-wise least related to the female.
鈥淲e sometimes call it a kind of Tinder for dogs,鈥 says Kerstin Ueckert, chair of the breed association 鈥楾he Dutch Kooikerhondje鈥. She is very pleased with Fit2Breed. 鈥淭he collaboration between our association and the Faculty of Veterinary Medicine goes back many years. We provided the data, and the faculty did the research. As a result, we now know a lot. However, that also makes it much more complicated to make good risk assessments in breeding. Fit2Breed helps us with this.鈥 Fit2Breed can play a crucial role. There is also a lot of enthusiasm from sister associations abroad, states Fieten. 鈥淚t is unique in the world.鈥
The goal is to gradually expand Fit2Breed to other dog breeds and eventually to cat breeds as well.
Text: Maarten Post | Images: Bas Niemans