PixelRN

The eco-pawprint of a pet dog is twice that of a 4.6-litre Land Cruiser driven 10,000 kilometres a year, researchers have found.

Victoria University professors Brenda and Robert Vale, architects who specialise in sustainable living, say pet owners should swap cats and dogs for creatures they can eat, such as chickens or rabbits, in their provocative new book Time to Eat the Dog: The real guide to sustainable living.

The couple have assessed the carbon emissions created by popular pets, taking into account the ingredients of pet food and the land needed to create them.

"If you have a German shepherd or similar-sized dog, for example, its impact every year is exactly the same as driving a large car around," Brenda Vale said.

"A lot of people worry about having SUVs but they don't worry about having Alsatians and what we are saying is, well, maybe you should be because the environmental impact ... is comparable."

In a study published in New Scientist, they calculated a medium dog eats 164 kilograms of meat and 95kg of cereals every year. It takes 43.3 square metres of land to produce 1kg of chicken a year. This means it takes 0.84 hectares to feed Fido.

They compared this with the footprint of a Toyota Land Cruiser, driven 10,000km a year, which uses 55.1 gigajoules (the energy used to build and fuel it). One hectare of land can produce 135 gigajoules a year, which means the vehicle's eco-footprint is 0.41ha – less than half of the dog's.