How hard is it to run a small business in New York?

Soho’s Little Lions cafe — a woman-owned small business — had to take the normal risk that customers just won’t like what you sell. But in Gotham, the café had to take another risk: that Mayor Bill de Blasio’s government would shut it down without warning — even though the business did everything it was supposed to do.

The Little Lions cafe is New York’s latest contribution to a global trend: cat cafes. In Japan and Europe, people — young women especially — have shown that they’ll spend money to eat in a restaurant where cats roam about (or, more often, sleep).

Customers are often people who can’t have cats themselves because they’re allergic, or because their landlords won’t let them.

And it’s for a good cause — the cats are strays or abandoned, and are up for adoption.

To open up downtown two weeks ago, Little Lions risked a lot of money and time. It costs $300,000 to plunk down a deposit to rent a little bit of New York’s expensive real estate and hire an architect to fit out a bright, open space for people and cats alike. Rent on similarly sized restaurants in the area runs $20,000 a month.

Little Lions and its architect also made sure to comply with Gotham’s regulations on food and animals. Basically, you can’t sell food where animals are present.

So customers enter the restaurant and buy their food. Then they pass through closed glass doors to go and eat their food, paying $11 an hour (separately from their food) to hang out with the cats. (Hey, it’s a weird city.)

Workers can also pass food that’s already been bought through a glass partition to serve their customers — and when they’re not doing that, the door is closed.

In writing about cat cafes months ago, I learned that anyone entering this business is careful to read up on the specific regulations — and that city health officials informally sign off on the designs.

Little Lions opened last week. It had a good first few days: plenty of business from neighborhood workers as well as people who made reservations in advance, and four cats got adopted.

But by Wednesday afternoon, a sign was up on the cafe’s doors: Closed, by order of the city Health Department.

Why? “Live animals other than fish in tank or service animal present in facility’s food and/or non-food areas,” the city says.

Well, yes, a cat cafe has cats. Customers already know this; that’s why they go there. Now, Little Lions must find some other way — other than what it worked on for months — to comply with the city’s ordinance. (I asked the owner yesterday about the closure, and got no comment.)

This might involve forcing customers to buy their food, then go outside again and enter through another outside door — highly inconvenient. The cafe could open today, or tomorrow, or not — depending on inspectors’ whims.

Meanwhile, thousands of dollars spent on high-end design and construction — wasted. Indeed, the arbitrary hand of government costs money.

Little Lions must pay its rent — about $600 a day — even when it’s closed. Customers whose reservations are canceled might not come back.

Passersby unfamiliar with New York’s ridiculous laws see a big bright “Closed by the Health Department” sign on the door, and think there must be something very wrong — rats (unlikely with cats), or rotten food. They won’t come back.

The city’s actions, then, risk not only a person’s hard work and investment — but workers’ jobs, too. When I went on opening weekend, three people were serving.

The city is imperiling what it supposedly wants more of: not chain stores, but something unique. And jobs, including for young people without much experience.

And really: Nobody needs saving from a cat cafe. If you don’t like cats, don’t go.

By contrast, all over the city, people do need saving from restaurants that spew smoke, blast loud music and send drunken patrons out to vomit (or scream at their boyfriends) on the street.

Yet nothing bad happens to you if you hire an “expeditor” to, you know, “work with” the city on these . . . issues.

If you wonder why Manhattan is just bars, banks and Starbucks now, that’s partly why.

If the cats can make it here, they can make it anywhere — but only because almost anywhere else respects the people (and cats) who put their own money and time on the line.

Nicole Gelinas is a contributing editor to the Manhattan Institute’s City Journal.