When someone calls up New Native to order one of their sling baby carriers, the customer service representative asks some questions to determine the right size. Like, “If you’re still pregnant, what was your pre-pregnancy weight?”

Every couple of weeks, the question is met with an awkward silence.

“Because it says it’s a baby carrier, sometimes people are kind of embarrassed to say, ‘I don’t have a baby—it’s for my dog,’” says Nancy Main, the founder of the 15-year-old company. Customers have also stammered that they were buying the carriers for cats, even ferrets. “They thought they were being weird, maybe.” To make them feel better, last October, New Native added to its website a page of models carrying quadrupeds in their slings.

Main is not selling her carriers to pet stores yet. “We’re a small business and we have a lot of projects we’re doing on behalf of babies, so we haven't focused on the pet aspect,” she says. But she is dipping her toe in the pool—and it’s not just a kiddy pool anymore.

Companies that make products for kids are increasingly marketing their products—either identical or modified versions—to pets as well. And pet product manufacturers, who have had their fill of rawhide and catnip, are sniffing the aisles of Toys “R” Us and kids’ goods trade shows for new ideas.

“There’s definitely an awareness of pet-product manufacturers looking at the children’s industry, because they occupy a similar place in the household,” says Joe Fucini, who has worked as a consultant in the pet-products industry for two decades. “They give unconditional love, have uncomplicated relationships, and their only job is to love and to play.” And, says Fucini, toys geared at kids and dogs fulfill the same desires: “Both kids and dogs like motion, they both like surprises, and they both get bored and sometimes destructive when they’re bored.”

Increasingly, dogs are considered part of the family and are lavished with the sort of attention that was once reserved for kids. Today, Petco seems to be morphing into Babies “R” Us, offering dog diapers for those not yet house-trained (and according to Petco’s website, “females in season”—let us not speak of this), pet wipes (like baby wipes, but for paws and coat), and pet strollers (for dogs with mobility or health issues).

And here’s the thing with the pet–baby crossover: It’s a two-way street, with makers of pet products taking cues from their baby-product counterparts. Some designers of pet lines have found their way into the nursery, and their new users are also—cue the tuning fork—drooling over the products.

Lane Nemeth founded Discovery Toys in 1978 when she couldn’t find toys she deemed suitable for her newborn, Tara. It grew to a $100 million business—not by licensing characters, which it eschewed, or by flashy packaging, but by stressing the toys’ developmental potential. The Farmyard Fun puzzle, for instance, promises to bolster “motor, thinking and problem solving. The toys were sold at house parties, like Tupperware. Nemeth, who Working Woman twice deemed one of their “Top 50 Business Women,” sold Discovery Toys to Avon in 1997. But she didn’t stay retired for long. Three years ago, her now-adult daughter Tara got a dog. Nemeth says that when she looked for toys for what she calls her “grand-dog,” a Cavalier King Charles Spaniel named Jade, “I said, ‘Oh my God … there’s nothing out there.’”

In 2004, she founded Petlane, a pet line. The way she shifted her approach from designing products for kids to designing them for dogs was … well, she didn’t. “Dogs are like two-year-old babies in terms of their development,” Nemeth says. “They stay focused for about as long as a two-year-old. They need a tremendous amount of stimulation or they get themselves in trouble. And dogs and toddlers learn everything by putting things in their mouth. With toddlers, I was really conscious of fabrics and textures.”