Laura McKirdy, a vet at Dalston-based Paragon Veterinary Group in Carlisle had to put down a dog which had chewed on its owner's cigarette device.
She said the dog she put down - which was a cross breed - showed signs of the effects of a nicotine overdose.
It had poor co-ordination and was sensitive to light, sound and touch.
She warned owners to treat their e-cigarettes in the same way as they would medicines and keep them out of reach of dogs or anything else that might accidentally eat them.
More top news
A sunspot 11 times bigger than Earth looks to be the largest in 25 yrs, but not necessarily the most active.The Met Office are monitoring it
Cumbria Police have been visiting local schools to encourage young people to have a safe and happy Halloween.
Talks begin today on what new powers should be devolved to Scotland. All five political parties at Holyrood will have their say.