Though wedded life has come easily to Amy Smart, it's presented challenges to her pets, which include two 16-year-old cats and a 9-year-old rescue dog.
"It was definitely an adjustment bringing my pets in with Slim," Smart tells PEOPLE of life with husband Carter Oosterhouse's 4-year-old bulldog. "My cats, they've grown up with my dog, but [Carter's] dog didn't really ever know cats, was never around cats."
Lucky for Slim, Smart's pair of felines have been nothing but hospitable during the adjustment process.
"My cats sort of trained him how to be with them," she says. "Now it's fine, everyone gets along all right. It's fun seeing them interact."
As an advocate of animal rescue, Smart would love to introduce another pet to the mix, but knows that for now, the couple has their hands full.
"I fall in love every time I go to a shelter, but realistically, four is enough right now," she says. "It's a full house, but we love it."
Instead, the actress channels her unending appreciation for animals into advocacy projects, like teaming up with the ASCPA to launch the Pet Armor Protection Promise.
"It's basically offering affordable health care to pets," she says of the national campaign. "So now, pet owners can afford to treat their pets, [which is important] especially because flea and tick season is starting right now."