Canine cancer risks increase with size and age, study shows
By Kim Campbell Thornton
Andrews McMeel Syndication
How big is your dog? Is he or she a purebred or a mixed breed? How old is your dog? The answers to those three questions could help to determine Luna or Leo’s likelihood of getting cancer -- and even the type of cancer they may be most prone to.
A biostatistical analysis by Nationwide of claims for more than 1.61 million dogs over a six-year period found that when it comes to a cancer diagnosis, size matters. Large and giant-breed dogs are at higher relative risk for cancer, and it usually occurs earlier in their lives, usually between the ages of 6 and 7.
That pattern holds true for both purebred and mixed-breed dogs, the data show. The retrospective study found a consistent correlation between increased dog size and increased risk of cancer across the populations, but purebred populations had a consistently higher risk than mixed breeds of the same size.
Breeds with the highest relative risk for a cancer claim were boxers, beagles and golden retrievers, while Pomeranians, Chihuahuas and French bulldogs had the lowest. While the risk of a cancer diagnosis rises with age, being a mixed breed, especially one of small size, appears to have a protective effect.
“Everything we see so far suggests that whenever you are crossing out of a gene pool, it would appear that in a highly genetically driven disease process like cancer, that you are diluting the chance that those genes will be mixed together,” says Jules Benson, BVSc, MRCVS, lead author of the white paper and chief veterinary officer at Nationwide. “There’s a genetic element, and there seems to be a size element that is present regardless of genetics.”
How was dog size defined? Toys are 10 pounds or less; small, 11 to 30 pounds; medium, 31 to 50 pounds; large, 51 to 110 pounds; and extra-large, 111 pounds or more.
What does all of this mean for your dog? It provides you with an evidence-based road map to keeping tabs on your dog’s health and catching disease early, when it’s more treatable.
For instance, large and extra-large dogs are at increased risk of bone cancer as early as 6 years old. That’s a good time to start paying closer attention to limping, lumps or bumps in breeds such as Rottweilers, Dobermans and greyhounds -- all prone to osteosarcoma.
Boxers are at high risk for skin cancer, with a lower-than-average age of 7.6 years at first cancer claim. Signs of skin cancer in dogs include firm, raised wartlike blemishes; inflamed sores; or odd-colored lumps or bumps on lips, mouth, footpads or toenail beds.
No matter what their breed or mix, more frequent home exams and veterinary exams are important as dogs age. By the time they are between 9 and 10 years old, even toy or small mixed-breed dogs, who have the lowest risk, move into the higher-than-average relative risk category for a cancer claim.
For medium-size, large or extra-large dogs, start thinking about routine diagnostics starting when they are 8 years old. The Nationwide data confirms that lymphoma is a significantly higher risk to middle-aged, mid-size dogs than other forms of cancer.
Being familiar with these types of evidence-based insights can help you and your veterinarian decide, for instance, when a limp can be managed with rest and pain relievers and when it warrants a closer look with X-rays.
Recognizing signs such as lethargy, decreased appetite, pale gums and a distended abdomen in large or extra-large dogs who are 6 or older can help to catch cancers such as splenic hemangiosarcomas in early stages when treatment may be able to extend a dog’s survival time or improve quality of life.
Here’s where to read the study yourself: bit.ly/3wI51Dt.
How to ensure
your pets’ care
Q: We’re writing our will, and it occurred to us that we also need to have directives for our pets’ care if we are incapacitated or dead. What should we include?
A: You’re smart to be thinking about that. Disasters come suddenly and unexpectedly. Planning ahead will help ensure that your pets get the care they need if you’re not around.
First, choose a primary person and a backup person who are willing to take charge of your pets if necessary (maybe you can promise to do the same for them). They should have keys to your house and a folder containing pet medical records, instructions for regular medications, including where they’re located and how you entice your pet to take them, a copy of your pet’s license, your veterinarian’s name and contact info, pet insurance information if you have it (and you should), and photos and a physical description of your pets.
Make sure your veterinarian is familiar with the care plan and has the names of the persons you’ve chosen to care for your pets. You can arrange to have your veterinarian run a tab or put charges on a credit card you have on file with the clinic in case you are unavailable, with the agreement that you or your estate will settle the bills. Carry a card in your wallet stating that you have pets, how many and what kind, and the names and numbers of the people who should be contacted to care for them.
In your will, you can’t leave money directly to a pet, but you can put a certain amount in a trust to cover expenses the caretaker will have throughout the pet’s life. Your attorney can help you set this up in a way that is most beneficial for your pet(s). -- Dr. Marty Becker and Mikkel Becker
Do you have a pet question? Send it to firstname.lastname@example.org or visit Facebook.com/DrMartyBecker.
Active people have
-- If you enjoy exercise, you’re a good candidate for living with a dog. A study published last month in the journal PLOS ONE found that owners’ exercise routines strongly influence the level of exercise their dogs receive. More than 3,200 responses were collected from dog lovers in France, Germany, the United Kingdom, Canada and the United States. Analysis showed that owners who performed any amount of vigorous exercise were more likely to have a dog that performed vigorous exercise. Owners who performed moderate exercise for more than five days per week were more likely to exercise their dogs for 60 to 90, or more than 90, minutes per day.
-- Your cat doesn’t have to be pedigreed to run with the fancy cats. The Cat Fanciers Association welcomes participation of companion cats in its new program, Companion Cat World, part of its mission to celebrate all cats and enhance their lives. Lifetime membership is available for a one-time fee of $16, a portion of which supports the well-being of community cats and cats in rescue and shelter situations. Benefits include a customized membership card with your cat’s picture; savings on cat food, toys, supplies and services; opportunities for you and your cat to attend CCW events and get to know other cat lovers; and the ability for qualified cats to compete in “Household Pet” classes at cat shows. Find out how to join at cfa.org/ccw.
-- Once again, it’s hard to tell which are the kids and which are the dogs. Met Life pet insurance released the Top 10 dog names of 2022, based on its database of cat and dog policyholders. For the first time, the name Luna beat out Bella for the top spot. The remaining names, in order of popularity, are Bella, Charlie, Max, Daisy, Bailey, Lucy, Cooper, Coco and Milo. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker
ABOUT PET CONNECTION
Pet Connection is produced by a team of pet care experts. Veterinarian Dr. Marty Becker is founder of the Fear Free organization, co-founder of VetScoop.com and author of many best-selling pet care books. Kim Campbell Thornton is an award-winning journalist and author who has been writing about animals since 1985. Mikkel Becker is a behavior consultant and lead animal trainer for Fear Free Pets. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/Kim.CampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.