Advertising spend rose 12 percent to $5.1 million in the fourth quarter.

The company has been faring well over the past few quarters, amid the financial turmoil, despite catering to the needs of pets, which can be difficult to afford in the current environment.

"I think they benefit more from people trying to save money first, people who are buying products not at their vets but online just trying to save some money. They are benefitting from more people doing that than from people just giving up pets," Woo said.

The Pompano Beach, Florida-based company's shares were up $2.12 at $17.51 in morning trade on Nasdaq.

COMPETITION LOOMS

Despite Monday's performance, Woo was concerned about the competitive pressures the company is likely to face from other online retailers, particularly from Amazon (AMZN.O: Quote, Profile, Research).

"If you look at the flea and tick medication, which is non-prescription, Amazon is about 30 percent cheaper than PetMed," Woo said, adding that flea and tick medication accounted for a bulk of PetMed's sales.

"Flea and tick is highly competitive, so obviously a lot of retailers have entered the business," PetMed CEO Akdag said on the call.

"We are a one-stop shop for pet medications, prescription and over-the-counter. Flea and tick preventatives are over-the-counter. The vast majority of retailers do not participate in the prescription medication. So that gives us a competitive advantage," Akdag added.