Lucy Postins has always been crazy about  pets

The British-born entrepreneur majored in horse studies (that's actually a field) before moving to San Diego and working for Solid Gold pet-food company. In 2002, when her Rhodesian Ridgeback Mosi came down with skin rashes and ear infections, she began whipping up homemade, healthful dog food. Mosi's health problems cleared up in a jiffy.

That's when Postins decided to turn Mosi's wholesome meals -- all made with gluten-free, non-GMO organic ingredients -- into a business, The Honest Kitchen. She now makes $30 million a year in revenue, selling "human-grade" pet food in 4,500 specialty shops and natural food retailers, including Whole Foods and Sprouts.

She can call it human-grade (with the Food and Drug Administration's blessing) because it's made in the exact same facilities as people food. In other words, if you're feeling peckish, and your pet is chowing down on some Honest Kitchen meals -- like Chicken & Quinoa or Fish & Coconut -- you can pick up a spoon and have a nibble. "There's nothing in there that you can't eat," Postins says.  

I helped produce a podcast with Postins for the media nonprofit, The Story Exchange. In the full interview, "The Honest Pet Food Jackpot," Postins talked about starting out in her kitchen and how she built a 45-employee business that has attracted investments from Alliance Consumer Growth and Clif Bar owners Gary Erickson and Kit Crawford. Find the Story Exchange podcast on iTunes.

Meantime, here are a few secrets to Postins' success.

1. She paired her passion with experience.

Sure, Postins loves pets, but she also has a degree in animal science, which helped her formulate the nutritional content of Honest Kitchen meals. And her years at kibble maker Solid Gold prepared her well to do her own pet-food marketing and product development.  

2. She caught the right side of a trend.

Luck has a lot to do with this, but Postins began selling healthy pet meals just as organic foods were taking off. When Postins was building her very first e-commerce site in the early 2000s, a random customer made a purchase -- before Postins could even place a test order. "I was just absolutely flabbergasted," she says. "It turned out we sort of got a tiger by the tail."

3. She stuck to her guns.

There were a few "musts" when Postins started her own business. The pet food had to be edible (to humans). It had to look like muesli, so owners would know what they were feeding their furry family members. And it had to be marketed as human-grade, which Postins viewed as a competitive advantage. She struggled to find a human-food manufacturer willing to make pet food -- and then she battled (successfully) with the FDA about her right to label it human-grade.

When starting your own business, one needs to have "a sense of stubbornness, a resilience to being defeated," Postins says. "You've got to just dig deep."