When New York state went on PAUSE on March 22nd, veterinary clinics remained open but stopped all elective medical procedures including spay and neuter. For pet owners, that might mean nothing more than an animal going heat inside a NYC apartment. But for New York City’s estimated 500,000 street cats, it’s a free-for-all.

Will Zweigart is a strategist at an ad agency during the day, but by night he rescues cats. He runs Flatbush Cats, a small non-profit animal rescue group in Brooklyn which focuses on reducing the number of street cats with a trap-neuter-return program. And now is a critical time.

Zweigart says that every single one of those street cats that is not spayed or neutered will be reproducing (or trying to) this spring. “Female cats can have 2 to 3 litters a year, a kitten that is 6 months old can have her own kittens after a few months. So after we get through the coldest parts of winter—February, March, April—that is the best time we have to play catch up and get as many cats outside spayed and neutered as possible.”

Listen to Amy Pearl's report on WNYC:

To get a sense of the volume, the ASPCA said that they spayed 35,000 cats last year, but not all of them were stray cats. With all spays and neuters on hold, Zweigart sees huge implications down the line.

“Cat rescuers have their own curve that they need to flatten,” Zweigart said. "They need to get as many cats fixed as possible to prevent thousands and thousands of kittens from showing up in city shelters. To have the global pandemic happening right during the peak period when we need to be doing as much work as possible is gonna have a multi-year impact, a big ripple on issues like the outdoor cat population.”

Zweigart works at his computer all day, but takes a daily “sanity walk” where he says he has seen a lot more cats out during daylight hours. And he’s been keeping a notebook, jotting down cats that he spots and if they look friendly or feral, any kittens that need to be rescued—all the big projects he has waiting for him when the ASPCA clinic opens again.

“We’re still taking in cats and trying to do our best to get them adopted through updated protocols," Zweigart said. "We can’t go full speed but the cats are still showing up at full speed.”

New York City’s shelters have reported a huge spike in people wanting to foster and adopt during the shelter in place rule. Zweigart is not surprised.

“Getting through this pandemic for me, personally it has been incredibly helpful to not just have resident cats but right now I have a foster cat in my lap, and it’s allowed me to focus on some positive thing I can do even while we’re stuck at home," Zweigart said. "I think it’s satisfying to be able to care for another being. I think it brings us joy to bring them joy.”

When asked what he most looks forward to when the shelter in place rule is lifted, Zweigart said “I’m really excited for the spay and neuter clinics to reopen so we can get back to work.”