On a warm summer morning, Monte was busy getting ready for his first day on the job. He stretched, took a power walk, and ate a healthy breakfast. A master of first impressions, he put on his best suit and tie before heading into his new digs at Spark Baltimore, a co-working office space for entrepreneurs.

He nailed his first day.

"Monte is very popular," says Amanda Khera, who shares an office with him. "And now, when I have to work late, he's here with me, which means he won't have an accident or be left alone for a long period of time."

Monte is a Yorkshire terrier. And Spark Baltimore is among the eight percent of businesses that now welcome pets in the workplace. That's up from four percent in 2014, according to the Society for Human Resource Management.

So why the proliferation of pooches at work? Studies show bringing your pet to the office can increase productivity, decrease absenteeism and foster a more creative environment.

Pet-friendly workplaces can also lower stress levels and improve health, not just for the pet parent, but for the entire organization. In fact, many small businesses are promoting the pet-friendly perk as part of their wellness programs.

"I love taking him on a couple walks throughout the day, which also gives me mental breaks to reset and jump back into work," says Khera, whose employer, the car-sharing company Maven, rents office space at Spark.

Human resource experts say as more people seek out pet-friendly offices, bosses get the benefit of workers willing to put in longer hours.

"If someone doesn't have to leave at five to go let the dog out, they're more likely to stick around and work an extra hour or two," says Edward Yost, a business partner at the Society for Human Resource Management in Virginia.

Yost says pet-friendly offices are becoming a boon for recruitment and retention, especially among Millennials, who are waiting longer to get married and start families. "Their pets are their children," Yost says.

They're also natural networkers.

"Somebody says, 'Aw, what a cute dog,' and two people who might not have talked before, this bring them together," says Beth Boots Workman, operations director at Spark Baltimore and mama to three pit bulls who come to work with her on rotation. They join their furry colleagues for the office's quarterly Yappy Hours and annual pet-friendly holiday party, where proceeds from ticket sales are donated to the local animal shelter.

Canine coworkers do, however, come with their share of challenges. Some employees might be afraid or allergic. It can be tough to find commercial office space that allows animals. Some pets are shy, or prone to stress in new environments.

And then there's the issue of cleanliness.

"What if your pet doesn't like to be left alone, and you have a two-hour meeting, and they retaliate by leaving a puddle in your office?" Yost asks.

If you're pondering a fur-friendly workplace, experts advise putting together a committee made up of pet parents and non-pet parents to draft a policy that takes into consideration allergies, phobias, potential pet-free zones, as well as these four often-overlooked points:

1. Insurance

Will this new offering drive up your premiums? It depends on the provider. Either way, it should be reported. Joey Price, a human resources consultant for small businesses, recommends checking with your insurance company before providing this perk.

2. Screening

What's the "hiring" process? Shervonne Cherry, Spark Baltimore's community manager, has pet parents fill out a detailed questionnaire about their animal. That's followed by a pet meet-and-greet with management, and a one-week trial period.

"It's not just like okay, everyone bring in a pet," Cherry says, emphasizing the need to make sure co-workers feel comfortable sharing any concerns.

3. Consequences

How will you ensure good canine citizens? The Bark, a dog culture magazine, recommends a "three strikes rule concerning behavioral breaches or human non-compliance" (not cleaning up after your pet, for example). But if a pet causes damage to the workplace, hurts someone, or acts aggressively, "he/she must be removed from the office immediately."

The Bark also recommends that pet parents sign a waiver holding them responsible for any damage done to office equipment or fellow employees.

4. The line.

Where do you draw it? Are cats allowed? If so, experts recommend giving them their own dedicated day, separate from dogs. How about ferrets? They're popular pets, but they're also mischievous and have a distinct odor that comes from musk glands in the skin. Does a worker need permission before bringing in a fish? Knowing and listing ahead of time which pets are allowed will streamline the request process.

"The only thing I might have to draw the line at," says Workman, "is a snake."