PetDx, a molecular diagnostics organization dedicated to harnessing genetics to enhance pet health, has announced the launch of OncoK9, a breakthrough multi-cancer early detection dog cancer blood test that allows veterinarians to detect cancer in dogs sooner via a simple blood draw.
How Does it Work?
Without the requirement for fasting or sample processing, OncoK9 employs regular blood draws. The sample is collected and transported to PetDx’s laboratory overnight at room temperature.
The sample is processed using proprietary procedures tailored for canine cell-free DNA analysis once it arrives. The veterinarian who submitted the sample receives a digital report stating whether or not a cancer signal was discovered.

Clinical Trials
Blood samples from over 1,600 client-owned dogs were used in a clinical study program in veterinary cancer detection done by PetDx. The CANDiD (CANcer Detection in Dogs) study investigated 1,577 of those dogs for clinical validation of OncoK9. The findings revealed that OncoK9 had a strong clinical performance, with high cancer detection rates and few false positives.
Testing After Age Eight
OncoK9 is recommended by PetDx as an annual screening test for dogs that are 8 years old or older and/or belong to cancer-prone breeds. The test is only accessible with a prescription and is used to help diagnose dogs suspected of cancer based on clinical findings or indicators.

Drawbacks of the Dog Cancer Blood Test
Overdiagnosis is also a possibility. This occurs when a test detects an illness that is present but unlikely to develop symptoms. Many human screening tests, based on the similar premise that early detection of asymptomatic disease is preferable, have been reduced because it has been discovered that they cause more harm than good.
Finding a malignancy that will never develop or make someone sick isn’t in their best interests if additional testing and treatment result in harm with no reward in terms of health or prolonged longevity.
The company study predicts an overall sensitivity of 48 percent for the test, assuming the techniques and controls for error and bias were sufficient and the data was accurate (all of which we must blindly trust in the absence of any scientific publication).
This indicates that just 48% of dogs with cancer, or fewer than half, will test positive. On the surface, this does not appear to be a particularly sensitive test. However, if we’re looking for cancer in dogs who haven’t shown any signs of illness, this could be a good thing.
We’d rather miss a case of cancer in a dog that isn’t causing any problems than misdiagnosing a dog with cancer who isn’t.
Positive Comments from a Veterinarian
The availability of a liquid biopsy test for veterinarians, according to Dr. Whitney Miller, Petco’s head veterinarian, is a “game-changer.”
“I think this is really gonna move the needle for veterinarians being comfortable with these DNA and molecular-based tests,” Miller says. “Because they are definitely not the norm of access to our diagnostic capabilities.”
Your Decision
Whether you believe this is prepared to market or not, it’s definitely a step in the right direction. Of course, as you can see, there are drawbacks to this test. However, if you would like the test to be performed, keeping the drawbacks in mind before you begin to panic if your dog’s test comes up as positive is critical. You don’t want to panic for no reason; wait for the veterinarian to discuss the results and the next steps.
Sources
OncoK9 Liquid Biopsy: Should Your Dog have this Test? | The SkeptVet
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