Dog owners are being warned to be vigilant after a massive increase in the numbers of animals needing surgery after swallowing harmful objects.

The Guiseley White Cross vets practice says the number of dogs having to undergo surgery to remove foreign objects from their stomachs has increased by 30 per cent compared with the same period last year.

Clinic Director Rod Beardshall said: “In the last month alone we have treated several dogs who have accidentally ingested something they shouldn’t have. In many cases it happens when the dogs have been left at home on their own and we are warning owners to always leave their dogs in a safe environment where they definitely can’t get hold of any harmful substances and objects.

“Chocolate is particularly harmful to dogs as it contains a stimulant called theobromine, which is a bit like caffeine, and is poisonous to dogs. The amount of theobromine differs in various types of chocolate but if a dog eats a large dose it can be fatal.”

The vets practice has removed everything from underwear to cotton reels from pet dogs’ stomachs and the most commonly ingested items are clothing, human medication and gardening products including slug pellets and pesticides.

Rod said: “Dogs are naturally curious and pick everything up using their mouths so it’s inevitable that from time to time they’ll eat things they shouldn’t.  Certain breeds are worse than others and young puppies are particularly at risk. When a dog swallows something it all comes down to the speed at which the dog is seen and treated. We recently treated one dog who had eaten a sock, luckily the owner brought him in within 20 minutes and we were able to remove it without surgery.”

He added: “We also recently treated a dog that had eaten slug pellets from the garden several hours before reaching the vets, unfortunately that dog didn’t make it.”