By Dial A Vet Veterinary Team
Last updated: 2 November 2026
Ham is everywhere at Christmas and in the lunchbox, and cats are very good at finding it. If your cat stole a small slice, it is unlikely to cause serious harm. Ham is still one of the less suitable meats for cats. It is cured, salty and often glazed or flavoured, and RSPCA Australia advises keeping processed meats out of a cat's diet.
Key takeaways
- A small piece of plain ham is unlikely to poison a cat, but it is not a good regular treat.
- Ham is cured with salt and preservatives. RSPCA Australia advises against feeding cats sausages and cooked manufactured meats, because they can contain sulphite preservatives.
- Sulphite preservatives have been linked to thiamine (vitamin B1) deficiency in pets, which can be fatal.
- Glazes can contain sugar, mustard, spices, garlic or onion.
- Ham bones should never be given to cats.
Why ham is not a great treat
Ham is pork that has been cured with salt and preservatives, and sometimes smoked or glazed. That makes it very different from a piece of plain cooked chicken.
RSPCA Australia's advice on feeding cats says to avoid sausages, sausage meat and cooked manufactured meats, as they can contain sulphite preservatives. It notes that many pet food safety incidents have been linked to sulphite-induced thiamine deficiency, which can be fatal. Whether a particular ham contains sulphites depends on the product, so it is simplest to treat ham as an occasional accident, not a treat.
Salt
Ham is a salty food. The ASPCA notes that excessive salt intake can cause increased thirst and urination, and in larger amounts vomiting, diarrhoea, depression, tremors and other signs. A small piece will not usually reach that point, but regular ham snacks add up, particularly for cats with heart or kidney disease.
Glazes and flavourings
Christmas hams are often glazed with honey, brown sugar, mustard, pineapple, cloves or other spices. Some glazes and stuffings include garlic or onion. The Merck Veterinary Manual explains that onion and garlic can damage red blood cells, and cats are especially sensitive. If your cat ate glazed ham or ham with stuffing, check the recipe or label. See our guides on onions and garlic.
Fat and the stomach
Ham fat and crackling can cause vomiting or diarrhoea, especially in cats who are not used to rich foods. Cornell notes that in most cases of feline pancreatitis, no obvious cause is found, so it is not right to say a slice of ham will cause it. It is still sensible to trim fat off and keep portions tiny.
Ham bones
Cooked bones can splinter. The ASPCA warns that pets can suffer injury or obstruction of the gut from bones, which can be serious and may need surgery. Wrap ham bones and put them straight in a closed bin.
Signs to watch for
- vomiting
- diarrhoea
- increased thirst
- reduced appetite
- lethargy
- gagging, retching or straining, if a bone may have been eaten
What to do now
- Remove any remaining ham and check whether a bone, glaze or stuffing was involved.
- For a small plain piece, offer fresh water and monitor your cat for a day.
- If they ate a large amount, a bone, or ham with onion or garlic, call your vet or the Animal Poisons Helpline on 1300 869 738 for advice.
- Do not try to make your cat vomit at home.
When to see a vet urgently
- repeated vomiting
- a painful or swollen tummy
- straining or no stools after eating a bone
- weakness, tremors or pale gums
Better treats for cats
- a small piece of plain cooked chicken, turkey or fish
- freeze-dried meat treats made for cats
- a little of their usual wet food
Cornell's Feline Health Center recommends treats make up no more than 10 to 15 percent of a cat's daily calories.
FAQ
Is deli ham worse than leg ham?
Both are cured and salty. Deli ham is often more processed and may contain added flavourings, so read the label.
Can cats eat prosciutto?
Prosciutto is a cured, very salty ham. It is best kept away from cats.
My cat ate ham at Christmas and has diarrhoea. What should I do?
Offer water and their usual food. Call your vet if it lasts more than a day, or your cat is vomiting or flat.
Talk with a vet
If your cat got into the Christmas leftovers and you are unsure what to do, book a video consult with Dial A Vet's real vets and vet nurses (we help with dogs and cats). Book a Dial A Vet consult.
References
- RSPCA Knowledgebase. What should I feed my cat?.
- ASPCA Animal Poison Control. People Foods to Avoid Feeding Your Pets.
- Merck Veterinary Manual. Garlic and Onion (Allium spp) Toxicosis in Animals.
- Cornell Feline Health Center. Feline Pancreatitis.
- Cornell Feline Health Center. Feeding Your Cat.
- Animal Poisons Helpline (Australia, 1300 869 738). Emergency Instructions.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If you are worried about your pet right now, contact your local vet or nearest emergency animal hospital.