Kelli Seepaul said she was in the process of moving from Vancouver to Toronto Thursday with her two cats, Finnigan, a tabby, and Willow, a Siamese, CBC News reported.
However, when WestJet staff were handling Seepaul's cat carrier, the bottom fell off, releasing the cats into the airport.
Seepaul was about to board her flight when she found out her cats were missing.
WestJet staff searched the airport's baggage area and found Finnegan, but after hours of hunting had yet to locate Willow.
Seepaul, who adopted both cats from the Squamish Society for the Prevention of Cruelty to Animals in March, said she was worried she would never see Willow again.
"They were just leaving out food, hoping she would come out and they would catch her and I explained that you can't just pick her up and catch her because she's an abused cat," she said. "I just don't know if they're doing enough. Their priority isn't to find my cats but it's to do other things and I just ... my priority is to find my cat that they lost."
WestJet said it was doing all it could to find the cat.