The number of pet cats and dogs being poisoned by their owners’ e-cigarettes is “significantly increasing”, UK vets have warned.

Last February a Staffordshire Bull Terrier called Ivy became the first pet in Britain to be killed by an electronic cigarette.

She died within hours of chewing on a bottle of nicotine-laced liquid used to fuel the smoke-free vapouriser, belonging to owner Keith Sutton, 56, of Redruth, Cornwall.

Now there’s been recorded a 300% increase in e-cigarette poisoning in the last 12 months, according to the Veterinary Poisons Information Service.

There are now an estimated four million people in Britain who have turned to electronic cigarettes.

White Cross Vets, in Walkden, Greater Manchester, also reported a huge rise in nicotine-poisoned pets after chewing on e-cigarette capsules.

They recently treated eight-month old Zuchon puppy Elton, who picked up a cartridge that accidentally fell on the floor.

His owner Emma Ronnay said: “I was at work when my housemate rang to tell me what had happened.

“The nicotine capsule fell out of his hand and before he could pick it up Elton had grabbed it.”

Lorna Siddons, Clinic Director at White Cross Vets, warned: “Elton was lucky because he received treatment straight away and we knew exactly what had happened.

“We gave him some medication to counter the effects of the poison and a charcoal treatment to line his stomach and he has made a full recovery.

“E-cigarettes have become incredibly popular and as the debate rages on about the health risks of these unregulated products.

“But one thing is crystal clear - if an e-cigarette is chewed or ingested by a pet dog it could be fatal.”

The battery-powered aid works by heating up the ‘e-liquid’ into a gas which the user inhales like real cigarette smoke.

Last February coach driver Mr Sutton had left a bottle of the liquid on his dining room table when 14-week-old Ivy bit into it.

She immediately started frothing at the mouth and vomiting and Keith rushed her to the vets, where she was given huge doses of steroids, but died from nicotine poisoning early the next day.

There are currently warnings on the bottles but grandfather Keith wants to see e-liquid become a controlled substance before it kills another animal.

The World Health Organisation has refused to endorse the device until long-term trials prove they are safe.

The e-liquid itself contains chemicals such as propylene glycol and polyethylene glycol 400 which are mixed with vegetable glycerin and various flavourings, plus varying amounts of nicotine.

While it would take a large dose of nicotine to harm a human, experts say a dog would only have to ingest 10 milligrams per kilogram of animal weight to be in danger.

Nicotine is a highly poisonous substance that can kill both humans and animals.

The lowest fatal dose was between 50 and 60 milligrams - equivalent to smoking about 20 to 30 cigarettes or drinking two high strength bottles of e-liquid containing 24 milligrams of nicotine each.

Nicotine poisoning induces vomiting, muscles spasms and seizures. In fatal cases it interferes with the central nervous system and causes respiratory failure.