In the last several decades, the number of genetic tests for dogs has increased dramatically.
Proper sample collection is the first and the most critical step in genetic DNA testing.

In the last several decades, the number of genetic tests for dogs has increased dramatically. Many breeders are testing their own dogs for the presence of different mutations, which are responsible for different disorders such as PRA, von Willebrand, Cystinuria etc. Also, many DNA tests are done to determine carriers of different coat colour genes in different breeds.

Originally, all genetic tests were developed and performed on canine blood samples for a number of reasons. Blood samples are an excellent source of good quality, as well as, quantity of DNA. A DNA test can be performed much faster and with a much better success rate on a blood sample compared to any other types of samples. With time, a number of laboratories began to offer the same DNA tests. In order to increase their competitive advantage and convenience for breeders, laboratories introduced a “swab collection technique”. This sample collection method rapidly spread among breeders and became the main method of collection of canine samples for genetic testing - it was easy to collect and ship them to the laboratory. Unfortunately, this new method has also created potential problems.

The introduction of the “swab collection technique” has led to a “contamination” problem in DNA testing. All DNA tests are very sensitive and specific and can detect a very low amount of DNA in a biological sample. This is why very similar DNA tests have been used by the police for forensic testing to determine a potential suspect from a crime scene. Since all swabs are collected from the dog’s mouth there can arise a potential problem, especially for places with multiple dogs. Dog’s saliva can be easily transmitted between several dogs during play. Consumption of other dogs’ body waste or canine-related material can lead to contamination of the mouth swab sample. Thus, swab collection from a dog must be performed with great precaution.

An ideal type of a sample for canine genetic testing is a blood sample: it is a little more costly for a breeder but it is faster and produces a more accurate result (since there is no potential contamination of DNA from other dogs).

If a breeder still prefers to submit swab samples for DNA testing, he or she should follow certain rules to reduce (but not completely eliminate) the possibility of contamination.

1. If a dog shares space with other canines, the dog to be tested should be isolated for at least one day from any dog.
2. Before collecting the swab samples, allow your dog to drink a lot of water and do not give food for at least 3 hours.
3. Swab samples should be collected from both cheeks inside of the mouth.
4. Once the samples are collected, they must be sealed in an envelope.

Proper sample collection is the first and the most critical step in genetic DNA testing. Any error at this step will be reflected in the final result