Some researchers are also concerned that pesticide exposures from flea treatments could have consequences for humans, especially small children.
“It’s one of those things that is incredibly unfair — it’s unfair for families, it’s unfair for their pets, it’s unfair for kids. And the truth is, there are better options,” public health scientist Miriam Rotkin-Ellman told Marketplace co-host Erica Johnson.
“We don’t need to put our kids at risk, don’t need to put our families at risk, our pets at risk.”
According to information Marketplace obtained from the Pest Management Regulatory Agency (PMRA), Health Canada received 4,726 incident reports for cats and dogs related to topical flea treatments between 2009 and 2013.
Health Canada receives reports about incidents related to Canadian products used domestically and in the United States. Almost two thirds (62 per cent) of these reports were for animals in Canada.
The deaths included 1,188 cats and 872 dogs, most of them in the United States.
Flea treatments can include collars, sprays, powder, shampoos and “spot-on” treatments, where pet owners dab a small amount of chemical directly onto the animal’s fur. Some of the treatments contain pesticides that target the nervous systems of fleas and ticks.
Spot-on treatments are responsible for approximately 80 per cent of the incidents, according to the PMRA. Most of the reports involve over-the-counter treatments.
For tips on keeping your pet safe, follow the conversation with @cbcmarketplace on Twitter, using the hashtag #pets.
Marketplace also investigated how pesticides in flea collars can transfer from the collar to elsewhere in the home, which could raise special concerns for families with small children.
“There’s mounting evidence that pesticides can be really harmful for kids at low levels,” says Rotkin-Ellman.
“When pesticides are on pets, they come into contact with kids all the time.”
The investigation, “Paws for Concern,” airs Friday, Dec. 5 at 8 p.m. (8:30 p.m. NT) on CBC Television. The show also tested dog harnesses, evaluating popular brands on the market to see if they actually work in an accident.
Dangers to small pets
Pet owners need to be extremely careful in how they choose flea treatments and how they use them on their pets, says Dr. Whitney Chin, a London, Ont.-based veterinarian.
Dr. Chin says one chemical common in over-the-counter dog treatments — permethrin — is of particular concern. Using too much of the chemical can be dangerous, and it is highly toxic to cats.
“I’ve seen it far too many times, unfortunately,” Dr. Chin says.
“Some people think, A cat is a small dog and I’ll just use a little dose,” Dr. Chin says.
Cats can also be inadvertently exposed if a dog in the home is treated with a product and “the dog or cat socialize, share the same bedding or if the cat grooms the dog.”
Chemicals transferred in this way can be enough to seriously harm a cat, he says.
According to the website of the Canadian Veterinary Medical Association (CVMA), “Toxicity [to cats] from dog flea and tick products is a medical emergency.”
Symptoms of exposure can include uncontrollable shaking, and the CVMA advises taking affected animals to a vet immediately. “The longer your cat is left to shake, the greater the chance of permanent damage (death included).”
Dr. Chin advises talking to your veterinarian before choosing a treatment product, and says that not all products on the market are dangerous.
New labelling rules
New labelling rules came into effect in Canada in 2012, requiring some treatments for dogs to show a clear warning label that the product can be toxic to cats.
However, products manufactured before the new rules were introduced were not recalled and may still be on the market.
Marketplace found treatments on store shelves in fall 2014 that did not have the new labels. Health Canada says it will investigate these cases.
Dr. Chin is concerned that the new warning labels do not go far enough and should more prominently alert pet owners to the dangers of poisoning.
Pet store staff may not always tell people who have both dogs and cats about the risks of exposure to both animals.
“People should be aware,” Dr. Chin says.
Human health concerns
Some researchers are concerned that pesticides in flea collars can also pose a risk to people, even when used properly.
Rotkin-Ellman at the U.S. Natural Resources Defense Council tested pets to see how much pesticide from flea collars the rest of us may be exposed to.
“Flea collars are designed to release a toxic substance that kills fleas on the pet’s fur,” she says. However, she says, “it also can get on the bedding, it can get on kids’ hands, it can go all sorts of places.”
Her team tested pesticide residues left on fur after monitoring a pet that wore a flea collar for three days.
“We found much higher levels than we expected,” she says.
The team found that kids could be exposed to higher levels than are considered safe by the Environmental Protection Agency. This was a particular concern for small children, who could be exposed to chemicals absorbed through their skin, or if they put their hands in their mouths.
Rotkin-Ellman says that exposure to the types of pesticides used in flea collars may be linked to behavioural problems, cognitive delay and problems with motor development.
She advises people who are concerned about pesticide exposure that there are other ways to control fleas, including bathing your pet and washing bedding regularly.