12/16/2013 at 04:40 PM EST
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."
The new dog has been a big distraction – in a good way and sometimes bad. "He's a biter, he's a pee-er, he's a barker," she says. "But he really does have a sweet soul and we have a trainer and we're working with him. It's a slow journey but we're getting him to be better."
Glanville did bury one of Chica's collars in her backyard, but she's not without hope that the little dog still might be found.
"I just need to hope for my children that someone found her in a good home," she says. "I was driving the other day and I saw her missing sign – we put them everywhere – and I got so sad. But I got excited to see her little face and I was like, 'Oh, you never know.'"