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
10,000 children have increased their chances of avoiding flu this winter after a county council campaign saw figures soar by 40%.
A look ahead over the festive period.
Boxes of Hope, Cumbria, the charity which gets local communities together and helps deprived children in Eastern Europe.