Dog owners in Northern Ireland are twice as likely put their pets' health at risk by feeding them Easter eggs than those in the rest of the UK, research has indicated.
Many of those who let their animals nibble on chocolate are unaware of the harm it can do, according to veterinary charity PDSA.
One of the chemicals it can contain - theobromine - can be lethal for dogs, the organisation explained.
PDSA vets and nurses witnessed more than 400 cases where dogs had eaten potentially life-threatening chocolate across the UK at its PetAid hospitals last year.
Research outlined in the charity's Animal Wellbeing report found 7% of owners across the UK admitted giving their pets chocolate. But in Northern Ireland alone, the percentage doubled to 14%.
PDSA senior veterinary surgeon Elaine Pendlebury said: "Many pet owners love giving their pet a treat but are unaware of the dangers of chocolate.
"The effects of chocolate poisoning in dogs usually appear within four hours of eating, and can last as long as 24 hours. Initial signs can include excessive thirst, vomiting, diarrhoea, a sore stomach and restlessness.
"These symptoms can then progress to tremors, an abnormal heart rhythm, raised body temperature and rapid breathing. In severe cases dogs can experience fits, kidney failure or even death."
The vet said high quality dark chocolates, which often contain the largest cocoa content, posed the biggest risk to dogs.
She said a small bar of dark chocolate contains more than enough theobromine to fatally poison a small dog such as a Yorkshire Terrier.