KNOXVILLE, Tenn. (WVLT) -- Sunday was a busy day at Dogwood Park, for both curious pets and their cautious owners.

"Sandy is very curious and if it smells good, she's going to eat it," said owner Erik McFarlane, "That's what dogs do."

"We all care what our dogs ingest. It's really important," agreed Carole Borges of North Knoxville. "Dogs tend to pick up anything, and natural sticks are really usually fine. But mulch can be very dangerous."

As gardens across East Tennessee start to grow, it's the month to mulch. The kind of mulch you use could harm your pet.

"There are certain dogs that will eat anything. It doesn't matter if it's mulch or the picnic table, or siding on the house, they'll eat it," said Dr. Rai Kaur Khalsa. Khalsa is a veterinarian at the Fountain City Animal Hospital.

She says mulches made from cocoa beans smell great to dogs, and contain the same chemical that makes chocolate unsafe. "It's theobromine, and it is toxic to dogs." In large volumes, it can even be fatal.

Ace Hardware of Bearden does not sell cocoa mulches, and says any of its mulches are safe for animals. "All the mulches here are organic, so they won't really harm your pets," said Geoff Cusick, a team leader.

But Khalsa says in large amounts, it may not matter. "Eating any kind of mulch in enough volume can make a dog very very sick, just because of the irritation effect of that much foreign material in their G.I. tract," she said.

Keep your pets away from your landscaping, starting with a hose.

"Put your mulch down, soak it really well, several times, as soon as it's down," said Khalsa. "And that sets up enough barrier that it's going to hopefully minimize those problems."