Sandra Harvey wears a mask when she plays with her pet, not for her protection but for the bird's sake. (CBC)

Public health officials in Toronto are investigating whether some pet shop workers have contracted a rare respiratory illness from a parrot that died.

The illness is most common among pet shop employees, veterinary staff and farm workers, and it's rare: between 1990 and 2006, there were 25 human cases reported in Canada.

Pet shop worker Sandra Harvey has been diagnosed with a possible case of psittacosis pneumonia, also known as parrot fever. People can catch it by breathing in infected dust from cages of infected birds.

Harvey has been coughing, feeling lethargic and having trouble breathing since she went to hospital last week, and she is still coughing.

"The cough was just so bad," Harvey said. "My chest, my lungs, my back just ached."

The parrot, called a white-bellied caique, died three weeks ago at a pet shop called PJ's at the Sherway Gardens shopping mall in Toronto.

Harvey, who works at the shop, said the bird was lethargic and shivering for a couple of days before it died.

Post-mortem tests confirmed the parrot died of psittacosis, a lung disease.

The store is strict about keeping birds and their cages clean, Harvey said.

No risk to general public

Toronto Public Health has warned pet store workers to tell their doctor they were exposed to the bird if they get:

• Feverish.
• Have a persistent cough.
• Have trouble breathing.

A spokeswoman for the store said the warning to employees was precautionary, and it's unlikely workers came into contact with the sick bird, which was kept in isolation from the time it entered the store until it was sent to the veterinarian facility where it died.

The risk applies to people who handle an infected bird or clean its cage, said Dr. Rita Shahin, associate medical officer of health for the agency.

"It's not felt to be a risk to the general public and people who've just passed through the pet shop wouldn't likely be close enough to the feces of the bird to be exposed to it," Shahin said.

Lab tests have yet to either confirm or rule out Harvey's diagnosis, and test results on the other workers are expected in a week.