Whether exhibiting her love of snow, enjoying a beautiful day in front of the LOVE statue, or demonstrating her preferred sleeping position, 2-year-old bernedoodle Nellie entertains her 558 Instagram followers with adorable poses and clever comments: "Tussy in the air like I just don't care," she posted, with one provocative pose.

This, of course, is actually the work of Nellie's owner, Jill Bergman, 27, who opened the nellie_the_bernedoodle account shortly after getting the dog two years ago - "It gave us a chance to brag about her without being too obnoxious to people who didn't want to follow her on our account," said Bergman, of Center City. That's because Nellie isn't just pretty and sassy, she's a do-gooder - as a certified therapy dog, she visits an autism support classroom at Mann Elementary School in Wynnefield to help students practice social interactions, and CHOP, to comfort cardiac patients and their families.

"There's an affinity for having the same dog and sharing what's in common," said Bergman, who notes that followers initially are drawn to her hashtags (#bernedoodle, for instance).

Pets have their own fitness classes and toothbrushes, their own gourmet food and TV channels. So in an age when parents are reserving Facebook pages for their human newborns, why not social-media pages for their fur babies? For owners, the accounts fill a universal need to share the good stuff with the world, and emphasize that they, indeed, are parents, too.

John White, founder of Social Marketing Solutions in Fort Collins, Colo., first noticed pet accounts in 2011 created by celebrities, on Facebook and then other networks, notably Instagram and Twitter - Kylie Jenner's Instagram for her pets being one of the early adopters. Normie & Bambi Jenner has 465,000 followers.

"Specific data is hard to come by on the number of accounts out there," White said, but a recent PETstock survey showed the trend is most popular in animal-loving New Zealand, where as many as 10 percent of all social-media users have created a separate account for their pets. "Animal lovers could actually be doing their followers a favor by creating a separate account. The people truly interested can interact with them and the others won't have their feeds clogged up with cat pictures."

Your cat's personal account also frees up space to market yourself, added Kyle Krajewski, editor of Chatterblast Media in Center City, so you "avoid encroaching on [your] own personal brand," should that be important to you, he said.

Lori Clark, owner of 8-month-old mixed-breed rescue Hazel, agrees, and believes her puppy's cuteness demands her own Instagram account: hazel_with_the_eyes.

"I was pretty sure posting pictures of her on my own account would be boring to most people I know," admitted Clark, 52, of Voorhees. Figuring she'd be followed by her kids and a few friends, she was surprised that strangers took note - so far, 74 people, most of whom she doesn't know.

Sometimes followers can turn into cash. Wallythewelshcorgi has become an "influencer," hawking pet products to his 150,000 Instagram, Facebook, and Twitter followers. It all started when Wally's owner, Marc Dalangin of Wharton, N.J., got a new camera in 2013, and, as a way to learn about it, challenged himself to take a picture a day of his new pup.

Wanting to "share our adventures with Wally," he uploaded his photos to the Flickr photo-sharing site and discovered a community of corgi owners. After adding Facebook, Twitter, and Instagram accounts, his followers quickly grew and advertisers realized that Wally would make a great marketer.

"Before we had 10,000 followers, vendors started asking if they could send us products," recalled Dalangin, 32. "We're very selective. We don't just say yes to everyone."

Clients include the monthly toy and treat box BarkBox, the Furbo dog camera, and Cunard Cruise Lines. Wally's work with PetSmart led to a Today Show appearance in October.

For the owner of Amelia, an 8-pound, 2-year-old domestic shorthair, the Instagram antics of her pet - posing with dentures or eyeing a pint of beer - provide both connection and documentation.

"It's like a scrapbook narrating her little life," said owner Valerie Cassis, 28, a dental student in Center City, of @amelia_kitten. "Hopefully it makes some other people happy out there, too."

Cassis equates Amelia's social-media account as a meeting ground, a virtual dog - er, cat - park.

"There's no real venue for cat people to meet each other or cat lovers to see each other out and about, so social media changes that," she said. "It challenges the idea that cat people are antisocial old ladies, although I don't mind the label cat lady."

On Benjaminfranklinbt's Instagram account, the 2-year-old Boston terrier poses in PJs, a birthday hat, and bow tie for his more than 600 followers.

"People get bored of adults posting everything they're doing because it's become monotonous, so we get pictures of him in the places we go," said owner Krystal Shannon, 29, of Point Breeze. "Like the first time at the beach when he was going crazy; at the casinos in Atlantic City; when he was in Houston and Boston. I have a picture of him throwing beads on the balconies of Bourbon Street."