BY day, they’re veterinarians, sea lion trainers and cat nurses; at night, they climb onto stage as the Pet Rox.

The all-professional-animal-care band – one of them’s a pet lawyer – hits the club circuit Friday for a benefit honoring the NYPD’s heroic K-9 corps, who risked their lives during the World Trade Center rescue effort.

“We know a lot of these wonderful dogs personally from working with them at Ground Zero,” said veterinarian Jeff Levy, one of Pet Rox’s guitarist-vocalists. He and the other band members cared for scores of beleaguered rescue dogs at the WTC.

Levy, co-founder of what he modestly calls an “elite garage band that’s pretty good,” says their music tends to relate to the animal world. So stay tuned for stuff like “I’m Gonna Buy Me a Dog,” “Octopus’ Garden” and “Rockin’ Robin.”

“We have a pretty big repertoire,” Levy said, adding that the group also plays the occasional T-Rex tune.

Pet Rox will donate profits from the event to help K-9 dogs when they retire with their partners at home.

Even the venue sounds right: The Raccoon Lodge, 1439 York Ave., at 76th Street, (212) 650-1775.

At the break, if you’ve got a question about your pup, kitty, parrot or hamster, it’s the right place to schmooze.