Finding out your dog has a tumor is one of the worst sentences a vet can say. But it isn’t automatically a death sentence, and a large new study makes the case that, for one particular tumor, the difference between tragedy and years of extra life often comes down to a single thing: catching it early. The catch is that this one is a specialist at hiding.
Researchers from the Royal Veterinary College, working with Utrecht University, combed through the primary-care records of more than two million dogs in the UK, 2,250,741 of them, to map out who gets a rare adrenal tumor called phaeochromocytoma, mercifully shortened to PCC. Their findings, published in PLOS One, do two useful things at once. They name the breeds at highest risk, and they hand owners and vets something the disease has always lacked: an advance warning.
The breeds carrying the highest risk
Out of that enormous population, 92 dogs were confirmed to have PCC, so this is genuinely rare. But the risk is far from evenly spread. Three breeds stood out sharply against crossbred dogs:
- The Soft-Coated Wheaten Terrier was a striking 30.9 times more likely to be diagnosed with PCC.
- The German Pointer came in at 11 times more likely.
- The Miniature Schnauzer was 4.7 times more likely.
Terriers as a group skewed higher, which fits a broader pattern, they’re more predisposed to endocrine tumors overall. On the other end, English Cocker Spaniels and Labrador Retrievers were among the breeds less likely to develop the tumors. The data also sketched a profile beyond breed: the typical diagnosed dog was around 10 to 11 years old (the median was 10.6 years) and neutered, and cases ran roughly two-to-one male. Younger dogs were far less likely to be affected.
Why this tumor is so easy to miss
PCC forms deep inside the adrenal glands, in their innermost layer, and what makes it dangerous is what it does to hormones. It overproduces the chemicals behind the body’s “fight or flight” response, which floods the cardiovascular system and overstimulates the heart. From there it can cascade into serious complications.
The trouble is that the warning signs, high blood pressure, collapse, a racing heart, an irregular heartbeat, look exactly like far more common heart and neurological problems. So the tumor gets mistaken for something else, or missed entirely. It’s badly underdiagnosed in dogs, and the study found the risk of a PCC diagnosis runs well above the human rate, by somewhere between four-and-a-half and 25 times. Making matters worse, close to half of all cases cause no obvious symptoms at all. Many are discovered only by accident, while a vet is scanning the abdomen for a completely different reason, and a large share aren’t found until after a dog has died.
The reason the numbers are actually hopeful
Here’s why a study about a scary tumor is genuinely good news. When PCC is caught early and the tumor is surgically removed, the outlook is often very good, and many dogs go on to live for years afterward. Left in place, PCC is frequently fatal. The entire prognosis, in other words, hinges on detection, and detection is exactly what breed data improves.
If you know your dog belongs to a predisposed breed, you and your vet can treat that as a standing reason to pay closer attention, to take vague cardiac-seeming symptoms seriously, and to keep an eye out during any abdominal imaging your dog happens to need. The study’s authors framed the breed findings as a kind of early-warning system: for owners of Soft-Coated Wheaten Terriers, German Pointers, and Miniature Schnauzers, and for their vets, knowing the elevated risk up front creates a real shot at earlier diagnosis and better outcomes. Big data, pointed at the right dogs, buys time, and with this tumor, time is the whole game.
“A predisposition is not a prophecy, and I never want an owner to read a number like 31 times and panic,” says Dr. Mara Chen. “What that statistic should buy you is vigilance, not dread. If you’ve got a Wheaten Terrier or a Miniature Schnauzer and they start having unexplained fainting spells or a heart rhythm that’s off, mention this study to your vet by name. This is a tumor where finding it early can mean the difference between losing your dog and getting years more with them, and that’s a conversation absolutely worth starting.”
None of this means a predisposed dog will get PCC; the vast majority won’t. It means that if yours is in a higher-risk group, the most powerful thing you can do is stay alert to the signs that are so easy to write off, because with this particular tumor, the earlier it’s found, the better the story tends to end.
References
- Bennaim, Michael, et al. “Incidence and risk factors for phaeochromocytoma diagnosis in dogs under primary veterinary care in the UK.” PLOS One, 2025, journals.plos.org.
- Royal Veterinary College. “New RVC study reveals breed predispositions and risk factors for rare adrenal tumour in dogs.” RVC News, 2025, rvc.ac.uk.
