In a nightmare scenario for a pet owner, a Massachusetts woman's cat was accidentally euthanized instead of receiving a flea bath.

Colleen Conlon arranged for her two cats to have a flea bath after she noticed fleas were bothering her "sensitive" dog. Her son brought them, one at a time, to nearby Broadway Animal Hospital, where Dr. Muhammed Malik had assured his mother a flea bath was the best treatment. The son dropped off the first cat, eight-year old Lady, filled out the papers handed to him, and left with the cat carrier to pick up the other cat, Little Bit. Then this happened:

But when Mr. Conlon returned with the second cat and said he'd take Lady home if she was finished with her bath, the vet surprised him when he asked, "You want the bodies?"

"At first he thought it was some cruel joke," Ms. Conlon said, but the veterinarian told her son he'd signed the papers.

It turns out that the papers Conlon's son filled out were somehow mixed up, and he ended up signing papers authorizing Lady's euthanasia.

Making the whole thing worse: Lady was originally the cat of Conlon's daughter, who died in a car accident in 2010.

"She was a beautiful cat and perfectly healthy," she said. "She was the one who would know when I was sad and would climb in my lap."

Conlon filed a complaint with the attorney general's office and has plans to talk with the state Board of Registration.

[Image via Shutterstock]