CONTRIBUTOR(S): Aimee Llewellyn-Zaidi, Christopher R Helps, Fear Free,
Genetic testing for dogs
Genetic testing for dogs
Genetic testing, or DNA testing, describes a number of different types of tests that examine the DNA of the dog to determine whether particular genetic variants (mutations) are present and, hence, whether these can be passed on to offspring. For owners, genetic testing can be a way to learn more about their dog’s health or genetic make-up. Responsible dog breeders can use these tests to help select breeding pairs to reduce risks of some inherited diseases, and also to identify desirable characteristics they would like in the puppies. Your veterinary surgeon may use genetic testing to aid in disease diagnosis, or to help determine risks of disease development.
©Douglas McCallum
What kinds of tests are available?
Single-gene mutations
Single-gene mutation tests look at the inheritance of specific genetic diseases (eg degenerative myelopathy), or traits (eg some coat colors), for example. These are very effective at determining the risks of having or passing on diseases or traits to offspring, which can be informative. These tests are often used by breeders to help identify low or no-risk dogs for a specific disease, when choosing dogs for breeding. Disease risks can be effectively eliminated with responsible use of these tests over several generations.
Panel testing for health
This describes a number of different products, but they generally test for a number of single-gene mutations, and sometimes include profiling, parentage, and breed(s) composition. As the information from these testing panels can be very complex, it is beneficial to choose a provider that has excellent support and advice. Look out for products that are tailored to be breed-specific, provide good advice, and explain both the results and how to use them for breeding.
Parentage testing
These tests can be used to determine the likely relationship between a dam, sire, and puppy. Occasionally there can be some uncertainty over a puppy’s parentage (usually who the sire is) in dog breeding and parentage testing can help to resolve this.
Dog profile/fingerprint
Profiling your dog is increasingly popular as a way of identifying a dog. A dog may have a microchip removed, or lost, but the genetic profile of a dog is permanent and cannot be changed.
Breeds composition
These genetic tests can help determine the likely recent heritage of your dog and are often used by owners of breeds they aren’t certain about, mixed-breeds or rescues either out of curiosity or to help predict breed-related characteristics – such as size, behavior, or health risks.
“Diversity” tests
These genetic tests vary enormously, but most attempt to either give some idea of the genetic diversity of the puppies that could result from a specific mating, or as a way of investigating the genetic diversity within a breed. These tests are not able to identify specific disease or health risks, or guarantee that increasing diversity will improve the health of an individual dog. This is in part due to this test being an over-all estimate of genetic differences, and doesn’t necessarily make a distinction between undesirable and beneficial mutations. It is generally accepted that reduced genetic diversity within a breed population can lead to more genetic health issues, and hence this should be avoided.
Specialist and diagnostic tests
These can be any number of genetic tests that are most often suggested by a veterinary surgeon. There are genetic tests that can diagnose disease without invasive procedures, look at risks for certain cancers, susceptibility to bleeding disorders, age-related problems, and much more. These tests are often used as part of a wider health care plan to diagnose or treat a problem.
You can find information on which specific genetic tests are available, and a list of international genetic test providers at dogwellnet.com, as part of Harmonization of Genetic Testing for Dogs.
Which tests should be used?
Many responsible dog breeders use genetic tests that are recommended specifically for their breed. You can find out about what tests are recommended before breeding from your veterinary surgeon, breed clubs, the Kennel Club, and your breeder. Health tests can be genetic/DNA tests, and clinical (physical examination) tests. When assessing a dog’s test results, it is important that you understand what the test results mean, not just that the test was performed. A dog advertised as being “DNA tested” can mean anything, and does not guarantee health! It is also important to recognize that testing for specific genetic diseases means testing for specific, known genetic mutations. A negative or clear result for the known genetic mutation means that the dog will not suffer from, or pass on, the known disease mutation. It does not mean that the dog will never suffer from a similar disease.
Can DNA tests impact health?
What genetic tests can help with:
- Use before breeding to reduce risk of perpetuating known disease(s) with genetic tests (eg single-gene mutations).
- Use as an aid for disease diagnosis, in conjunction with veterinary care.
- Use for predicting risks of disease(s) or other attributes (eg linkage tests, Late-onset diseases).
- Finding out about “breed types”.
- Predict the underlying genotype of some phenotypic traits (eg tests for coat color, length, etc).
- Parentage testing.
What genetic tests can’t help with:
- Diagnose all inherited genetic conditions in dogs; if the genetic mutation has not yet been discovered it cannot be tested for.
- Inform you about non-inherited diseases.
- Tell you the age of disease onset, the severity of disease or the impact on welfare if your dog has a genetic disease.
- “Prove” your dog’s breed for Kennel Club registration.
- Treat a disease.
- Guarantee a dog’s “health”.
How can I access a test?
Owners can access genetic testing directly (called Direct-to-consumer testing), where in most cases an owner can order a DNA testing kit online, and provide a cheek-swab sample. For some tests, a veterinary surgeon will need to take a blood sample for submission. There are also a number of tests that are accessed only through veterinary professionals, as they are either part of a wider diagnosis, or should be undertaken in conjunction with veterinary guidance and advice.
It is always recommended that any decisions about an individual dog’s health should be made with a veterinary professional’s advice.
Where can I get advice on genetic testing?
For registered pedigree dogs within the UK:
- The Kennel Club website has an array of free online health information and resources that can help dog breeders to make informed breeding decisions: www.thekennelclub.org.uk
For any pedigree dog, or other dog types, and international information:
- The International Partnership for Dogs (IPFD) hosts an online resource, dogwellnet.com, which provides information on genetic testing, international breeding regulations and recommendations, Breed Club information, and the Harmonization of Genetic Testing for Dogs (HGTD/Harmonization) project – a portal for information on Genetic Testing Providers (labs), and genetic tests. There are two major components: Quality Testing Database and Genetic Counselling resources.