Dana Brewington, who sells Do-Rites disposable dog diapers, with Prince, her Pomeranian. She invented a dog diaper after her old dog, Mr. Chips, became incontinent. (John Kelly/The Washington Post)

Necessity is the mother of invention and Dana Brewington, a retired Federal lawyer who lives in Chevy Chase, Md., is the mother of the premium disposable dog diaper.

“Diaper,” because some dogs suffer from incontinence. “Premium,” because each diaper is custom made. “Disposable,” because, as Dana puts it, “Why anyone would want to wash a dog diaper, I don’t know.”

Good point.

“They look so cute in it,” said Clintonia Chance, as we watched a frisky Pomeranian named Prince model a diaper from Dana’s company, Do-Rites Premium Disposable Dog Diapers. (Motto: “Even a good dog can have a bad day.”)

Clintonia is a seamstress, and we were in her workshop, in the District’s Takoma neighborhood, where she runs Fashions By Clintonia. She can make just about anything that involves a needle and thread. She can whip up a custom wedding dress. She makes costumes for area theater, dance and opera companies. For a while, she specialized in clothes for full-figured customers, including a man with a 70-inch waist.

Dana Brewington, left, with Clintonia Chance, a seamstress and designer, who sews diapers for Brewington in her D.C. workshop. (John Kelly/The Washingotn Post)

In March, Clintonia answered an ad Dana had placed in the Washington Informer. It read “Sewers needed.”

Clintonia said: “The prom season had died down, so I had some time.” Dana needed people to sew her Do-Rites dog diapers.

“It’s not an everyday task,” said Clintonia, who had never before sewn dog diapers.

Dana supplies the raw materials: small disposable (human) diapers along with fabric and elastic that Clintonia transforms. She reduces the length of the diaper, reduces the width of the crotch area, cuts a hole for the dog’s tail (if the dog has a tail), lock-stitches that seam so the diaper’s liquid-absorbing polymer pellets don’t spill out, and adds elasticized straps that will loop around the dog’s neck.

She also sews in a Do-Rites label, whose logo features a dog sheepishly looking down at a puddle of its own making.

No such problem with Do-Rites.

“For me, it was a lifesaver,” said satisfied customer Susan Natow when I called her in Pennsylvania. After back surgery, Susan’s dachshund, Barbie, was partially paralyzed and incontinent. Susan’s waking hours seemed to be arranged around Barbie’s accidents. She had tried jury-rigging a diaper and a baby onesie but it didn’t really work. An acquaintance told her about Dana’s product three years ago, and she’s been a fan ever since.

“It costs me $2,500 a year for diapers, but we have a life,” Susan said.

Dana invented the diaper — $32 for a pack of six, including shipping — when her previous Pomeranian, Mr. Chips, developed diabetes. “It was grit. It was determination. But mostly it was because I had to do it for Mr. Chips,” she said.

Though she was a lawyer — litigating for such agencies as the Federal Deposit Insurance Corp. and Environmental Protection Agency — Dana had sewn since she was a girl. She used to make neckties for Washington TV news anchor Max Robinson. Through trial and error, she perfected her diaper design. She has been granted several patents.

Other dog diapers have been introduced in the past decade, and Dana has struggled to maintain her toehold in the market. The world of dog diaperdom is cutthroat, especially when you are a small-business woman beset by competition.

Dana retired from the government in 2010 and has focused on Do-Rites since then. She says she could pay to have her company rank higher on Google searches but resents the expense. It would be cheaper to have the diapers made someplace like China or Vietnam, but “I strongly believe in bringing jobs back here to the country.”

That’s why Dana has about a half-dozen subcontractors such as Clintonia, scattered from Florida to New Jersey.

“I thought about going on ‘Shark Tank,’ but I don’t talk that fast,” Dana said of the TV investing show. “I don’t know if I’d be able to stand up to Daymond [John]. I just make good dog diapers, that’s all. I’m the only one that can fit everything from a teacup to a 100-pound wolfhound dog.”

Dana thinks other animals could wear her diapers: chimps, rabbits . . .

“Cats?” asked Clintonia, who said she was more of a cat person than a dog person.

Yes, Dana said. But “the question is, will a cat allow you to put a diaper on it?”

A cat-ad-strophe?

Those crazy Brits did it. The Citizens Advertising Takeover Service raised $33,500 to replace all the ads in a London subway station with photos of cats.

[Could a subway station filled entirely with cat photos improve your commute?]

I wrote about the group last month and how it aims to fight the barrage of dispiriting advertising in the public space. James Turner of CATS said 131 Americans were among the 683 donors. The posters will feature photos of adoptable cats from a South London shelter.

Now CATS has to figure out which Tube station to commandeer. Among the possibilities: Mew Gardens, er, Kew Gardens.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/johnkelly.