Betsy Boyd had a tough decision to make. The Baltimore college professor's 17-year-old cat Stanley had stage 4 kidney failure and faced a dire prognosis. Boyd was considering a kidney transplant for her long-time best friend, but was weighing the cost of putting the cat through such a risky procedure. She was also, of course, concerned about the financial expense.

"I asked myself if I could make such an exorbitant sacrifice for my best friend," Boyd wrote, explaining the situation. "Even though I’m a college writing professor and freelance editor — and my paychecks reflect as much — even though my semi-retired freelance journalist husband and I have twin sons, age 3, a voice inside said, 'You can, and you must — this is Stanley.'"

Friends tried to stage an intervention, saying the money should be used for her children's education.

"Then I talked to Stanley. I explained how much I wanted him to live but said I didn’t know what I should do," she wrote. "He purred a lot. He wanted to live, I believed. But he wouldn’t, couldn’t — not with a bum couple of shriveled kidneys."

Boyd opted to have the surgery for Stanley. His donor was a homeless cat that the family adopted after the procedure. The bill came in just under $17,000.

The cost of pet ownership

puppy at shelter That puppy sure is cute, but it will create a lifetime of vet bills. (Photo: InBetweentheBlinks/Shutterstock)

We all know there are going to be expenses when we bring home a pet.

The annual cost of owning a dog or cat (or other non-human friend) varies, depending on its species and its size, according to estimates from the American Society for the Prevention of Cruelty to Animal (ASPCA). That means roughly $737 for a small dog, $894 for a medium dog, $1,040 for a large dog, and $809 for a cat. That excludes one-time expenses like spaying/neutering and equipment like crates or carriers.

Out of those annual expenses, owners typically spend between $210 and $260 on recurring annual medical expenses. Those include regular checkups, vaccinations and preventative medications like heartworm pills and flea and tick medicine.

But the unexpected can happen and then you're back at the vet for an ear infection, skin allergies or something more serious.

Nationwide pet insurance policyholders spent more than $96 million in 2017 to treat the 10 most common medical conditions affecting pets.

At an average cost of $255 per dog, skin allergies were the most common health issue among insured canines. Bladder/urinary tract disease was the most common concern for cats with an average cost of $495. The most expensive medical condition on the list for dogs is dental disease ($400) and diabetes ($889) for cats.

Where to draw the line

dog prepares for an X-ray A recent survey showed the average dog owner is willing to spend more than $10,000 to save a pet's life. (Photo: PRESSLAB/Shutterstock)

A 2013 study by the American Humane Association found that one in 10 pets adopted from a shelter was no longer in the home six months later. One of the main reasons given for the animals' return was the cost of pet ownership.

Thanks to advances in veterinary medicine, our pets have the ability to live longer than ever before, but that comes with a hefty price tag. While some people don't hesitate when faced with diagnostic tests, transfusions or chemotherapy, others have a finite number they're willing to spend.

A 2017 poll of 250 dog owners and 250 cat owners by online lending resource LendEDU found that the average dog owner is willing to spend more than $10,000 to save their pet’s life. Cat owners, on average, will spend just shy of $3,500.

Some will spend way more, which seems like great news for pets ... and vets. But not all vets think it's a great idea.

"It’s wonderful that people are willing to spend $10,000 or $20,000 to deal with their sick pet, but ethically it puts us in quicksand," Douglas Aspros, the former president of the American Veterinary Medical Association and the manager of a veterinary clinic in White Plains, New York, tells Slate.

"If a client wants me to do a $20,000 surgery on a cat, the practicality has to go beyond, 'There’s someone willing to pay for it.' As a society, should we be promoting that?" Some veterinary practices, he says, use companies that will offer credit with very high interest rates to people with low incomes, just so they can afford their pets' vet bills.

"How much responsibility do we have for getting them into that?"

Roxanne Hawn of Golden, Colorado, spent nearly $31,000 in 23 months to save her dog, Lilly. "Probably not the best financial decision I ever made," says Hawn, author of "Heart Dog: Surviving the Loss of Your Canine Soul Mate."

Her blog follows Lilly's illness and details her veterinary bills and how she paid them. "I did not have anyone to tell me where this might end up," Hawn says. "When you're in the crisis, it's easy to hand over your credit card and say, 'Save my dog!' But once you start on a path like this, if it's going to be a lengthy or even lifelong battle, then it becomes harder to stop."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

How much would you spend to save your pet?
Dogs and cats are part of the family and when they're sick we often will spare no expense to save them.