Brandi Glanville: Losing Our Dog ‘Has Been Heartbreaking for All of Us’

Brandi Glanville

updated 12/16/2013 AT 4:40 PM ET

originally published 12/16/2013 AT 4:35 PM ET

No stranger to drama, Brandi Glanville is once again at the center of a firestorm on Monday night’s episode of The Real Housewives of Beverly Hills (airing at 8 p.m. ET on Bravo).

While away for a girls’ weekend in Palm Springs, Calif., with the other housewives, the former model, 41, gets a call that one of her beloved dogs has been stolen from her house – but Glanville isn’t buying it.

“We have computers and TVs and iPads and everything,” in the L.A. home that she rents, “and they took one dog? It didn’t make sense to me,” she says.

And so unfolds the commotion surrounding little Chica, a rescue pooch Glanville adopted three years ago from a shelter in Van Nuys, Calif. At fault, says Glanville, is her former assistant, who had a bad habit of leaving doors open.

“There’s coyotes and cars,” she tells PEOPLE. “I don’t know what happened. I’ll never know. I can’t blame her 100 percent. But I let her go because of the irresponsibility factor I just couldn’t imagine [someone] losing my dog.”

Though the entire family – including remaining dog Sugar and Glanville’s sons Mason, 10½, and Jake, 6½ – is devastated by the loss, they bounced back fairly quickly after the arrival of Buddy, a Chihuahua mix they adopted from the same shelter.

“My therapist said the best thing to do was to get a new dog right away,” she says. “Sugar was also very depressed – she just laid around and cried.”