DNA testing has become increasingly popular amongst humans; looking at areas such as genetic diseases and ancestry. Now it’s time for your pet to get in on the action! DNA based genetic profiling gives veterinarians, breeders and pet owners alike, an easy means of verifying parentage, managing disease and determining the likelihood that your pet, will display other interesting traits.
Every nucleated cell in your pet’s body contains the molecule known as deoxyribonucleic acid or DNA. The molecular structure of DNA was discovered in 1953 by James Watson and Francis Crick, who revealed that DNA held the genetic information that determine an organism’s unique characteristics. Further advances in science now allow us to learn more than ever before about the genetic make-up of the animals in our lives.
Most pet DNA tests are performed using blood tests or cheek swabs. A swab is rubbed on the inside of the pets cheeks to collect a sample of cells. The cells contain your pet’s DNA and will be processed and assessed by the laboratory.
DNA testing for dogs
Each dog breed has a unique set of characteristics. The mix of these characteristics expands even further in mixed breeds. Mixed breeds are generally healthier as they have a broader gene pool than pure breeds.
Looking into your dog’s genetic back ground can give you an insight into the characteristics and predispositions of your dog. Some insights include life expectancy, size estimate, or even what diseases it has a disposition to and should be monitored for. The results can even help to determine the best type of diet and exercise regime to keep your dog in optimum health.
Like people, dogs inherit physical and character traits from the members of their family tree. Unfortunately this can include genetic disorders, so understanding their ancestry can be a handy tool. Some breeds are more prone than others to particular inherited diseases. DNA-based genetic testing is used to identify carriers of around 50 hereditary diseases plus a few traits such as coat colour and texture.
Genetic testing in dogs can assess;
· The dog’s ancestry for multiple generations, by comparing their genetic profile with hundreds of breeds, types and varieties
· Predict you dog’s target adult weight range
· Determine the best diet for your dog
· Traits such as coat colour and length
· Create a better understanding of your dog’s breed-related behavioural characteristics
· Screen for your dog’s breed-related risk of developing certain genetic diseases
A dog’s parentage can be established because the laws of Mendelian inheritance. A dog has two copies of each gene; one inherited from the mother and one from the father. This means that DNA testing can establish which dogs are the biological parents of a given litter.
One of the most commonly requested tests is clear-by-parentage, which is testing the parent dogs for genetic diseases to ensure that all of their puppies will be free from those conditions. If the parents are clear from disease causing genes, the pups are referred to as clear-by-parentage. Pups are often still DNA tested to ensure their parentage.
While the parents may be cleared of genetic conditions themselves, it is also important to screen for carrier status. This is because if both parents are a carrier of a genetic condition they are at risk of producing an affected pup.
In terms of DNA testing for genetic conditions, there are three possible results;
- Clear or normal: the disease-causing gene is not present, so the dog cannot pass on a disease gene to its young.
- Carrier: of the pair of genes coding for a particular genetic disorder, one is disease-causing and one is not. The dog is considered to be a ‘carrier’ and it will not exhibit disease symptoms or have medical problems as a result, but will pass on the disease gene to 50 per cent of its offspring.
- Affected: both of the genes are the disease-causing variant and the dog will be medically affected by the disease, as well as passing on a disease-causing gene to all of its offspring.
DNA testing in cats
Cats are also eligible for DNA testing. Currently available testing can detect over 40 genetic diseases, reported in terms of known relevance to the specific breed evaluated. More than 20 traits can be revealed through DNA testing including blood type, coat colours, coat types, and morphology.
Genetic diversity information is also available for the tested cat and the overall breed population, and related breed groups. Genetic diversity is essential for survival of a species and aid breeders when selecting a breeding pair. Breeding for genetic diversity may help to decrease the incidence of kittens affected with recessively inherited diseases (two copies of the affected gene being present) and diseases influenced by multiple genes.
DNA testing in birds
Our feathered friends can also have DNA tests too, but for different reasons to cats and dogs. There are many species of birds which are considered to be monomorphic, meaning that both genders have the same physical appearance. A Sun Conure is an example of a monomorphic species. When it comes to a breeder wanting to create a new breeding pair, a DNA test for sexing can make it much more straight forward. Bird DNA sexing is done using a blood spot, a feather sample or even an eggshell sample. Once the sample arrives at the laboratory the sex chromosomes are assessed and the gender of the bird identified.
Genetic testing is usually conducted by veterinarians and breeders. There has been a steady increase in the use of testing as it has become more affordable and breed clubs promote the use of DNA tested animals in breeding programs.
The Department of Primary Industries Code of Practice for the Responsible Breeding of Animals with Heritable Defects that cause Disease states that breeders are now bound by the Act to ensure their breeding programs are set up for the long-term health and wellbeing of their pedigree line.
When looking for a DNA test for your four-legged (or two legged) friends, always make sure the lab is accredited to carry out DNA testing. The accreditation mainly concerned with DNA testing companies is ISO 17025. Look out for the more efficient companies that offer a reasonable turnaround time and provide you with the assistance and information you need for the test.
Genetic information revealed from a DNA test can help you take control of your pet’s health as well as learning some interesting aspects of what makes your pet the way they are. It is a useful tool for animal breeding and can be utilised to maximise genetic diversity which is an investment in the future health of the breed.