Move over, darling... Tiddles is here

They are already man's best friend. Now, it seems, dogs are our bedfellows too. More than half of Britons let their pet sleep on their bed, according to a new study, while almost three-quarters allow their animals to share the bedroom at least. Such is the nation's devotion to four-legged friends that one in three people admit they would rather share their bed with a pet than with their partner.

But the research – conveniently commissioned by a home furnishing retailer to coincide with its launch of life-size pet dummies that allow shoppers to test whether a mattress is big enough for them and their cat or dog – shows that sleeping with animals is affecting people's ability to get a good night's rest. Pets wake up 71 per cent of owners with their snoring, twitching and nocturnal wriggling. More than two-thirds of the 2,000 people surveyed last month complained their animal takes up too much space. As a result, 39 per cent have booted their partner – rather than the offending beast – out of bed.

Cats edge out dogs as the most popular bedfellow, but four per cent of those questioned claimed they would be happy to sleep with a rat, and four per cent with a reptile. Animal-lovers from Wales are the most likely to allow pets to sleep with them. Half of Britons let their animals share their bed because they want them to enjoy a comfortable night's sleep.

Julia Jones-Collins, 26, an advertising manager, and her builder husband David Collins, 28, let their cats Peggy and Billy sleep on their bed, even though they make David sneeze and give him itchy eyes. "When David bought Peggy for me for a present, we didn't realise he was allergic to cats," said Mrs Jones-Collins, of Heath and Reach, Bedfordshire, who uses mattress and pillow protectors to reduce the impact of the cats' fur. "By the point she had settled in our house she had decided our bed was her bed.

"With one cat it was fine, but with two it's a bit annoying. But they are just so comfortable we don't feel that we should kick them off. We could probably do with a bigger bed now we have got two cats."

In response to Britain's sleeping arrangements, Ikea, which commissioned the research, has created in-store models of pets so customers can ensure a new mattress will accommodate them and their animals. The "crash test doggy" and "crash test moggy" are currently being trialled in the retailer's Croydon branch and, if popular, could be rolled out across the UK.

But Elaine Pendlebury, senior vet at the PDSA veterinary charity, does not recommend sleeping with a pet. She warned that animals can carry diseases that can be transferred to humans, including skin complaints, such as ringworm, and stomach upsets. She said dogs and cats actually like having their own territory and knowing their position within a household.