A labradoodle had to be rushed for emergency treatment in Salisbury after wolfing down a dozen chocolate eggs.
Bruce, from Hampshire, also ate several bars of dark chocolate, which vets say could have cost him his life.
Bruce's owner, Alison Rothery, is backing calls for pet owners to keep all chocolate safely out of reach and to seek urgent help if their animals do get hold of any.
Alison, from Fordingbridge, said Bruce managed to get hold of the chocolate, despite it being on a shelf she thought he couldn't possibly have reached.
She said: "I came down to find Bruce’s bed full of chocolate bar wrappers. We must have left the door ajar and he’d obviously sniffed his way in, stood up and helped himself."
Alison realised Bruce would need medical attention once she saw the amount of chocolate he had eaten.
The labradoodle was rushed to the vets, as Alison couldn't be sure how long the chocolate had been in Bruce's system for.
Why is chocolate bad for dogs?
Chocolate contains a chemical called theobromine which is poisonous to dogs.
The amount depends on the type, with dark chocolate the most toxic.
It mainly affects the guts, heart, central nervous system and kidneys and common symptoms are vomiting, diarrhoea, restlessness, hyperactivity and seizures.
Dave Hollinshead, Senior vet surgeon, said it was clear Bruce had "ingested a toxic amount" of dark chocolate.
The labradoodle was given an injection, which made him vomit most of the chocolate and quite a few wrappers. After further checks, Bruce was allowed home.
Dave Hollinshead is urging pet owners to be careful this Easter bank holiday.
He said: "Easter eggs are obviously a big favourite at this time of year. But while they are a nice treat for adults and children, they are a real hazard for pets."
Bruce's owner, Alison was thrilled to get him back on the same day and said the dog was back to normal after feeling "little sorry for himself for a day or so."
She said: "We’re taking absolutely no chances now.
Ever since it happened, we’ve been putting any chocolate in the fridge and that’s where the Easter eggs will be going from now on."