A shuttered Manhattan puppy mill that allegedly sold sick and abused dogs to unwitting customers now faces a lawsuit from the city Department of Consumer Affairs.

The lawsuit against the former Chelsea Kennel Club and its owner Yardena Derraugh was filed by DCA Commissioner Lorelei Salas in Manhattan Supreme Court Monday, asking a judge to impose nearly $4 million in fines on Derraugh and force her to pay more than $52,000 in restitution to her customers.

The Humane Society carried out an undercover investigation of the shop, which was on Seventh Avenue near 22nd Street, for two months in 2017, revealing terrible conditions and routine cover-up of sick pooches.

Amid the probe, Derraugh closed up shop after six years in business, the court papers say.

“Defendants should not be allowed to simply close their shop and walk away,” the lawsuit said.

“And while restitution will not make a sick puppy better, or bring back a beloved pet that has already died, it will ease some of the financial burden on impacted consumers and make defendants accountable for the despicable behavior.”

Derraugh regularly sold sick puppies by lying to customers and doctoring the pets’ medical files, the suit alleges.

She allegedly put healthy puppies in the storefront while keeping the ill ones in cages in an “isolation room.”

And despite having no veterinary degree she would medicate them herself or have staff google how to medicate them and put them on antibiotics in an effort to prevent further sickness, the court papers allege.

“Even the sickest puppies were treated with defendants’ crackpot, back-alley home remedies: puppies with high fevers, persistent diarrhea, open wounds, severe conjunctivitis, or persistent upper respiratory infections were given cold baths, aspirin, adult Robitussin, and other medicines designed for humans, birds, cattle,” the lawsuit alleges.

The small dogs were also physically abused, the lawsuit claims. They were “forcibly held down, grabbed by the neck, smacked with towels, hit with bones, shaken, and frightened by banging on their cages,” the court documents charge.

In one case, a man unknowingly bought a sick French bulldog for nearly $5,000, only for it to die a month later of a respiratory infection. The owner was stuck with $15,000 in vet bills, the lawsuit claims.

Derraugh did not immediately return a request for comment.