Anti-tobacco campaigners have a new message for smokers - if you won't quit for yourself, do it for your pets.
A new study has revealed that pets may be more at risk from second-hand smoke than humans.
Campaigners have long highlighted the risks passive smoking poses to humans, but it can be just as harmful for pets.
Studies conducted in the US and Britain have found smoking around pets increases their risk of getting cancer.
Auckland vet Dr Ryan Cattin says it's hard to deny the effect of tobacco toxins on animals he's cared for.
"I recently had a cat with a lung tumour and the owner smoked quite a lot, so we did discuss that and whether, in that case, it may have potentially been associated with the cause for that cat," he said.
The SPCA says the nicotine in cigarettes can have a deadly impact on all animals.
"It's every living being, so fish, birds, parrots… anything that is alive is going to get impacted from the smoke," said SPCA CEO Andrea Midgen.
She says dogs with longer noses are more vulnerable to nasal cancers, whereas dogs with shorter noses have a greater chance of getting lymphoma or lung cancer.
And it's even worse for cats - they're four times more likely than dogs to develop cancer.
"Cats, particularly, can get the carcinogens in their fur, and you know how they like themselves and clean themselves," said Ms Midgen. "They're taking that all inside."
Although the number of pets that die from second-hand smoke is unknown, about 500 people die each year in New Zealand from smoking or second-hand exposure.
More motivation for smokers, particularly those who are animal lovers, to stub the habit out.