Man’s best friend may be nature’s worst enemy, study on pet dogs finds

New Curtin University research into the overlooked environmental impact of pet dogs has found far-reaching negative effects on wildlife, ecosystems and climate.

While ecological damage caused by cats has been extensively studied, the new research found dogs, as the world’s most common large carnivores, present a significant and multifaceted environmental threat.

Lead researcher Associate Professor Bill Bateman, from Curtin’s School of Molecular and Life Sciences, said the research found that human-owned, pet dogs disturb and directly harm wildlife, particularly shorebirds, even when leashed.

“As well as predatory behaviour like chasing wildlife, dogs leave scents, urine and faeces, which can disrupt animal behaviour long after the dogs have left,” Associate Professor Bateman said.

“Studies have found that animals like deer, foxes and bobcats in the US are less active or completely avoid areas where dogs are regularly walked, even in the absence of the dogs.

“Dog waste also contributes to pollution in waterways and inhibits plant growth, while wash-off from chemical treatments used to clean and guard dogs from parasites can add toxic compounds to aquatic environments.

“In addition, the pet food industry, driven by a vast global dog population, has a substantial carbon, land and water footprint.”

Associate Professor Bateman said addressing these challenges required a careful balance between reducing environmental harm and maintaining the positive role of dogs as companions and working animals.

“Dogs are incredibly important to people’s lives and their roles range from providing companionship to contributing to conservation efforts as detection dogs,” Associate Professor Bateman said.

“However, the sheer number of pet dogs globally, combined with uninformed or lax behaviours by some owners, is driving environmental issues that we can no longer ignore.”

The study also sheds light on barriers to sustainable pet ownership, finding that while the dog food industry is a key factor in national sustainability action plans, only 12 to 16 per cent of dog owners are willing to pay more for eco-friendly pet food, largely due to rising costs. Additionally, a lack of awareness among owners about the impact of dogs on the environment compounds the issue.

“Many owners simply don’t realise the environmental damage dogs can cause, from disturbing wildlife to polluting ecosystems,” Associate Professor Bateman said.

“Others may feel their individual actions won’t make a difference, leading to a ‘tragedy of the commons’ where shared spaces like beaches and woodlands suffer cumulative degradation.

“Restrictive measures such as banning dogs from sensitive areas are necessary for protecting vulnerable species but they are not a complete solution. We are calling for a collaborative effort between dog owners, conservation groups and policymakers to develop strategies that balance pet ownership with environmental care.”

The paper, ‘Bad Dog? The environmental effects of owned dogs,’ has been published in Pacific Conservation Biology and can be found online here: https://doi.org/10.1071/PC24071