Massive increase in dogs poisoned by chocolate and grapes – fed to them by their owners.dailymail.co.uk, July 14, 2008. Record numbers of dogs are being poisoned after being fed chocolate, grapes and raisins by their owners as treats, say vets.Vets have seen a surge of almost 50 per cent in the number of dogs falling ill after eating chocolate.In 2006, vets made 790 emergency calls about chocolate poisoning to the Veterinary Poisons Information Service. Last year, the figure was 1,166. [ See ] See also the article: Toxic Plants and Pets.