For many owners, Christmas is a time of year they like to spend with their families. And while our pets might be 'one of the family', when it comes to food, some common festive favourites can be seriously harmful for them.

As tempting as it is to give in to pleading pets and include leftovers or even a full pet's portion in the festive menu on Christmas Day, this can actually put our pets in danger.

In order to avoid an emergency trip to the vet this Christmas, vet charity PDSA is urging pet owners to resist the temptation to give human food to pets, and offer them a healthy pet treat, a winter walk or a new toy instead.

PDSA Vet, Olivia Anderson-Nathan, advises: "Pets need far fewer calories than people. So if a medium-sized dog, such as a Beagle, was to eat a full roast turkey dinner, this would be the equivalent of a human eating three Christmas dinners! All of those extra calories aren't good for our pets' waistlines."

As well as excess calories, unfamiliar foods can also have undesirable consequences.

Olivia adds: "Our pets' digestive systems can react badly to sudden diet changes, particularly when fatty foods, such as roast vegetables or pigs in blankets, are involved. Eating these foods can lead to very upset stomachs – cleaning up vomit and diarrhoea is not the way anyone would want to spend Christmas Day with their pet!"

Some festive foods commonly eaten at Christmas even contain ingredients that are poisonous to our pets.

"Raisins, alcohol and onions are just three ingredients that can potentially poison cats and dogs, causing severe illness," explains Olivia. "Foods containing these items, such as stuffing, gravy, mince pies, Christmas cake and Christmas pudding, should never be given to pets. If they do get their paws on them, get advice from your vet straight away."

Raisins, sultanas and grapes can cause kidney failure in pets, sometimes even if only a few are eaten. Alcohol can cause vomiting or in large volumes organ problems, and pets will be affected by amounts that humans can easily tolerate. Onions and other alliums put pets at risk of life-threatening anaemia.

Leftovers can also be a potential hazard for pets. Bones shouldn't be given to pets as they can be a choking hazard, and can splinter, causing internal damage. Bones can also get lodged the stomach and intestines - a potentially fatal problem that often requires life-saving surgery. Even if these life-threatening problems are avoided, bones can cause our pets uncomfortable constipation due to high calcium levels.

When it comes to showing our furry friends how much we love them, 'puppy dog eyes' can seem irresistible. But spending time with is a far better way to show our love for our pets.