“Man’s best friend” can be a homeowner’s worst nightmare when the time comes to obtain a property insurance policy.

Dog bites cost home insurers more than $300 million, or 15% of all homeowners’ liability claims, according to the New York-based Insurance Information Institute. The average bite-related payout is now about $21,200, up from $16,600 in 2002.

As a result, some insurance companies are refusing to issue property policies to owners of “biting breeds,” or asking those dog owners pay higher premiums or sign liability waivers, an institute vice president, Loretta Worters, said.

According to data compiled by the institute, many insurers, such as State Farm and Farmers Insurance Group, determine coverage based on bite history, not breed. However, American Family Insurance will not issue property policies to owners of pit bull terriers, Rottweilers, among other breeds, and Mercury Insurance offers discounts to homeowners without dogs.

The Chubb Group does not have any breed-specific exclusion policies, but its agents work with policyholders to determine whether they need additional coverage based on the size or breed of a dog, or other potential liability risks, a spokesman for the company, Mark Schussel, said.

Following major hurricane-related claims, insurance companies are looking to curb their losses by excluding some policyholders, such as those with certain types of dogs, the senior director of legislative services and mediation for the American Society for the Prevention of Cruelty to Animals, Jill Buckley, said.

An Upper West Side resident, Wendy Rothstein, said she lost her renter’s insurance policy several years ago after adopting a Chow Chow mix, Macey. “That he has some Chow in him shouldn’t be the bottom line,” she said. “There are a lot of things in a home that are potentially dangerous. If you own a buzzsaw, you have a high risk.”

According to the Centers for Disease Control and Prevention, 10 dog breeds — including pit bulls, German shepherds, and Chow Chows — are responsible for the highest number of bite-related fatalities.

But Ms. Rothstein said her dog is gentle, biting only “pillows and shoes.” Still, she has had a difficult time securing a policy because of its breed. Recently, she took out a renter’s policy with another agency that provides only limited liability coverage. “It doesn’t make me feel safe,” she said.

In the past couple of years, Ms. Buckley of the ASPCA said she has fielded an increased number of complaints from homeowners and renters who are having trouble securing property insurance. She said she recently received a letter from a man whose insurance company threatened to cancel coverage if he did not give up his ailing 14-year-old Rottweiler. “He was devastated, because the dog had been a family member,” she said. “It was tragic.”

However, would-be policy owners should never lie to insurance companies about their pet ownership, according to Ms. Buckley. “If they find out at a later date, they’ll cancel the policy from the date of issue,” she said.

Instead they should try to convince their insurance brokers that their dogs, especially those that are elderly, spayed or neutered, or professionally trained, pose little liability risk, she said. Dog owners who feel they are the victims of “breed discrimination” should contact their state department of insurance or their local legislators, Ms. Buckley said.