Analysis of the carbon footprint of pet food production also revealed that the industry emits more greenhouse gases each year than countries such as Mozambique and the Philippines.

The University-led project is the first to assess the global environmental impact of pet food production.

Researchers say rising demand for pet food – driven by an increase in pet ownership around the world – should be factored into initiatives aimed at improving sustainability of the global food system.

The team analysed data on the main ingredients in more than 280 types of dry pet food available in the US and Europe, regions which account for two thirds of global sales.

They found that around half of dry food is made up of crop plants – such as maize, rice or wheat – with the rest consisting of various animal or fish products. Researchers combined the findings with data on the environmental impacts of producing the ingredients.

Around 49 million hectares of agricultural land – roughly twice the size of the UK – are used annually to make dry food for cats and dogs, scientists said, which accounts for 95 per cent of pet food sales.

Annual greenhouse gas emissions were found to be 106 million tonnes of carbon dioxide. A country producing the same levels would be the world’s sixtieth highest emitter, researchers said.

The full environmental impact of the industry will be higher as the new study only looked at dry pet food production, the team said.

Even accounting for the use of by-products in pet foods, the feeding of companion animals plays a role in environmental change. This is a topic that has been previously overlooked, but we have shown that pets and how they are feed should be considered alongside other actions to reduce climate change and biodiversity loss.