The Hawaiian Humane Society this spring plans to start building Hawaii’s first high-volume spay-and-neuter clinic focused on “free-roaming” cats to reduce their numbers on Oahu.

The new $700,000 clinic at its Moiliili shelter would follow the Humane Society’s $11 million renovations there last year, which included new dog and cat houses, roads, parking, utilities and a clinic that opened in October that treats animals for all kinds of conditions and spays and neuters them before adoption.

As part of its overall $1 million building and startup cost for the new clinic, including hiring a veterinarian who specializes in high-volume sterilizations, the Humane Society plans to buy a van and more traps that it’ll use to catch and transport cats to the new clinic before possibly returning them to their so-called “cat colonies.”

Many details still need to be worked out, such as the cost of the sterilizations and who would pay for them.

“The van will be used on a case-by-case basis, a community-by-community basis,” said Hawaiian Humane Society spokeswoman Allison Andrade Gammel. “Whether there’s a fee (for the sterilizations), whether we’re picking up and dropping off will depend.”

Clinic to target cats

The additional 1,550- square-foot spay-and-neuter clinic would be built out of the society’s newly vacated, 31-year-old admissions area.

It would include sterilization of dogs, but the real focus is on cats without owners — specifically, “cat colonies” around the island that are typically fed by humans.

“Our real priority is to be able to sterilize free-roaming cats,” said Pamela Burns, Humane Society president and CEO.

Burns hopes that just one new specialist in “high-volume” sterilizations will be able to spay and neuter 8,000 cats each year — and could possibly be complemented with additional surgeons.

The state contributed $350,000 and the city added $125,000 for the project in separate grants. ABC Stores added another $50,000. Donations covered the rest of the $1 million costs.

The nonprofit group Cat Friends expects to sterilize more than 4,000 cats this year at its Kalihi clinic and welcomes the Humane Society’s plans.

“We hold three clinics once a month just for cats, and we’re doing well over 400 a month,” said Jennifer Kishimori, the organization’s founder and president. “But it’s hard to keep up with the growing population. The more spay-and-neuter clinics the better. I’m excited about their clinic opening. There’s no such thing as competition when it comes to spay and neutering. The more the merrier.”

Last year people brought 12,800 cats to the Humane Society, which sterilized more than 8,000 animals in all, including cats.

“We’re at maximum capacity with what we’re able to do now,” Burns said.

It’s impossible to get an accurate census of the number of cats that don’t have owners on Oahu. But a 2015 survey by Ward Research Inc. for the Hawaiian Humane Society offered a glimpse at the scope:

Some 17 percent of respondents on Oahu said they regularly feed cats that do not belong to them. On average they each fed 9.4 cats.

But specific individuals said they regularly fed as many as 75 and even 100 cats.

The Hawaiian Humane Society hopes to replicate encouraging data reported by other organizations that have embraced the high-volume spay-and-neuter philosophy on the mainland.

It cited data that showed a shelter in Asheville, N.C., saw a 79 percent decrease in euthanasia after launching a “low-cost high-volume spay/neuter clinic.” Another, in Florida, saw a 66 percent drop in cat admissions after 50 percent of free-roaming cats were sterilized in a single ZIP code.

“Clearly, there are a lot of stray cats out there,” said Dr. Eric Ako, a veterinarian and owner of The Pet Doctor in Kahala, who serves on the Humane Society’s board of directors. Ako is also past president of the Hawaii Veterinary Medical Association, its current executive vice president and one of the founders of Windward Community College’s veterinary technical program.

In Hawaii, veterinarians see a slight bump in kitten births between May and August, Ako said.

“There is kind of a peak season, but there’s really no lows,” he said. “It’s all the time in Hawaii. Many of my colleagues, not just me, have been volunteering their time with many organizations, including Hawaiian Humane. We recognize that we need to make a bigger dent than what we’ve done. That’s why this new high-volume, high-quality (clinic) is exciting. Veterinarians have long waited to solve the problem.”