Only a small fraction of pet owners in the United States carry pet insurance. An estimated 1 to 2 percent of the nation’s nearly 90 million pet dogs and more than 94 million pet cats are insured, industry statistics show.

Nevertheless, the marketplace has grown from one pet insurer, Veterinary Pet Insurance (now called Nationwide), in 1982 to at least 11 companies today, including the Hartville Pet Insurance Group (now called Crum & Forster), which offers insurance through the A.S.P.C.A. The North American Pet Health Insurance Association cited a growth rate of 12 to 15 percent in policy holders over each of the last two years.

“There’s definitely an uptick in the number of insured pets out there,” said Chris Middleton, president of Pets Best, an insurer in Boise, Idaho. He said that since 2013, the 11-year-old company has seen a 60 percent increase in the number of employers seeking pet insurance for their workers. But unless owners have faced high vet bills in the past (as Mr. Middleton has with his “rock-eating hound,” he said), many are deterred by the monthly premiums.

Much like human health insurance, pet insurance comes with a dizzying array of options. A basic plan for certain illnesses and accidents can cost $20 or less a month; more comprehensive policies covering annual wellness exams, vaccinations, blood work and a range of treatments start at around $63 a month.

In general, cats tend to cost less to insure than dogs. Many pet insurance companies charge more for breeds prone to certain medical conditions, like cancers or heart disease; a large dog, like a Great Dane, will cost more to insure than a Chihuahua.

“My best advice is find others who have the insurance you’re interested in, talk to your vet or ask for referrals from the company,” said Heidi Ganahl, founder of Camp Bow Wow, a dog-boarding and -training franchise. She said that before she sold the company in 2014, she offered her 40 employees pet insurance and always insured her own pets. “The biggest thing you want in any policy is the catastrophic stuff,” she said.

“By and large, most pet insurance is primarily there for injury and disease,” not for wellness, said Dr. Christopher Gray, the director of Michigan State University’s Veterinary Medical Center in East Lansing. He does not insure his two dogs and two cats. His recommendation: Look at deductibles, co-payments and whether a policy covers a pet throughout its lifetime or ends when it hits a certain age.