From nutmeg to pork crackling: The common Christmas foods you shouldn't feed to your dog.

Most dog owners have done it – slipped their furry friend something small from their own plate or pantry. A bite of meat, perhaps, or a bit of cheese.

But it’s important to be aware that some seemingly harmless human-friendly ingredients can, in fact, make your dog incredibly ill.

Australian Veterinary Association president, Dr Paula Parker, said, “Unfortunately, there are a number of foods that are toxic for pets and if they access these foods, either directly from being fed by someone or indirectly from picking it up off the floor, it can cause serious health issues, or in some cases even be fatal.”

Watch: ’tis the season of festive doggos.

The signs of pet food poisoning can vary from case to case, but common symptoms include vomiting, diarrhoea, lethargy, fever and loss of appetite.

For owners who wish to provide the occasional treat, Dr Parker advises pet owners to offer quality pet treats that contain the right nutrients.

“Speak to your veterinarian about treats that will be suitable for your pet,” she said, “and if you suspect your pet has eaten something toxic, you should contact your veterinarian immediately.”

Below are some of the foods dogs shouldn’t eat this Christmas (or ever!):

Chocolate

Chocolate is toxic to dogs and cats thanks to a compound called theobromine. While humans can metabolise theobromine efficiently, it takes far longer in a dog's system and can build up to toxic levels.

As the RSPCA notes, "the symptoms of theobromine ingestion can include restlessness, excitement, hyperactivity, nervousness, trembling, vomiting, diarrhoea, increased drinking and increased urination, increased heart rate, muscle tremors, seizures and possibly death."

Nutmeg

Nutmeg is one of the lesser-known poisonous foods for dogs. It contains Myristicin, a compound that can cause issues with the nervous system, even when ingested in small amounts.

Complications can include tremors and seizures and even death.

Ham, pork crackling, sausages and turkey skin

These foods have a high-fat content, which can have serious — even fatal — consequences when ingested by dogs.

"Dogs often have a reasonably bland diet. A sudden influx of fatty festive foods can wreak havoc on their gut, leading to gastroenteritis, diarrhoea, or pancreatitis," noted Dr Anne Fawcett from the University of Sydney School of Veterinary Science.

"They can also suffer from intestinal obstruction or perforation due to foreign bodies like bones, kebab sticks and toothpicks."

Grapes and raisins

Grapes, sultanas and raisins can cause acute kidney failure in dogs. They should be avoided altogether.

So be careful no pudding or Chrissy cake crumbs fall to the floor during dessert.

All-year-round foods to avoid...

Macadamia nuts

Macadamias can be toxic to dogs. Symptoms will likely occur within 12 hours and can include vomiting, increased temperature and elevated heart rate.

Onions and garlic

Onions and garlic can cause gastric irritation and anaemia if they are consumed in large quantities.

Dairy products

Because dogs don't possess significant amounts of lactase (the enzyme that breaks down lactose in milk), dairy products - including cheese - can cause digestive problems including gas, diarrhoea and vomiting.

Raw eggs

Raw eggs come with the chance of food poisoning from bacteria such as salmonella or E. coli.

Raw fish

Raw fish can carry harmful bacteria like salmonella and listeria. Plus certain varieties, including salmon and trout, can also contain a parasite that causes "fish disease" or "salmon poisoning disease"; the first signs are vomiting, fever, and big lymph nodes. This can be avoided by fully cooking the fish.

Raw or green potatoes

'Potato poisoning' is caused by the consumption of too much Solanine - a glycoalkaloid naturally produced in green or raw potatoes, potato skins, and the foliage from the potato plant. Solanine toxicity can cause heart problems, difficulty breathing, and gastrointestinal upset.

Large quantities of tomato or salt

Too much salt can lead to sodium ion poisoning in dogs, which can be fatal. Symptoms include vomiting, diarrhoea, depression, tremors, high temperature, and seizures.

Featured image: Getty.