By Dial A Vet Veterinary Team
Many cats will lap up the liquid from a roast chicken tray or a bowl of soup left on the bench. Plain bone broth made only from bones and water is not toxic to cats. The problem is that almost every broth and stock made for people contains onion, garlic or both, and cats are more sensitive to these ingredients than dogs. Salt and fat are the other hidden issues.
Key takeaways
- Cats are the species most susceptible to onion and garlic poisoning, including from cooked, powdered and dried forms.
- Read the label. Onion, garlic, leek, chives, shallots and onion or garlic powder are common in human broths and stocks.
- Stock cubes and many cartons are very salty, which is a concern for cats with kidney or heart disease.
- Broth is mostly water. It is not a complete food and should not replace a balanced cat diet.
- Related: onions and cats, garlic and cats, pancreatitis in cats.
Why onion and garlic are such a concern for cats
Onions, garlic and their relatives contain compounds that damage red blood cells and cause a form of anaemia. Cat red blood cells are particularly vulnerable. The Merck Veterinary Manual notes that cats have been affected after eating less than a teaspoon of cooked onion, and that concentrated forms such as powders and dried soup mixes are the most common culprits. Garlic is several times more potent than onion. Signs often appear a few days after the meal, so a cat that seems fine the next morning is not necessarily in the clear.
Other ingredients to watch
- Salt. Many cats in Australia live with chronic kidney disease as they age, and some have heart disease. Salty broths are a poor choice for them.
- Fat. Rich homemade broth can cause vomiting and diarrhoea.
- Bone pieces. Strain homemade broth thoroughly. Small cooked bones splinter.
- Seasonings and additives. Herbs, spices, yeast extracts and flavour enhancers add nothing useful for a cat.
Can broth help a cat drink more?
Vets often encourage more water intake in cats, especially those prone to urinary problems. Wet food is the most reliable way to do that, and RSPCA Australia recommends including moist foods in the diet regularly. Some owners use a little plain, unsalted, onion-free broth to make water or food more appealing. If you want to try this, ask your vet first, particularly if your cat has kidney disease, diabetes, a heart condition or is on a prescription diet. Never use broth to coax a cat that has stopped eating. Loss of appetite is itself a reason to see the vet.
If you choose to offer broth
- Use a pet-specific broth, or a human product with no onion, garlic, leek, chives or added salt in the ingredient list.
- For homemade broth, simmer plain bones in water only, chill it, remove the fat and strain out every fragment.
- Offer a small amount and watch how your cat's stomach copes.
- Keep it as an occasional extra rather than a daily habit.
Signs to watch for
- Vomiting or diarrhoea
- Reduced appetite or hiding
- Lethargy or weakness
- Pale or yellow gums
- Fast or laboured breathing
- Red-brown urine
The last four can point to anaemia from onion or garlic and can take a few days to appear.
When it is an emergency
Take your cat to a vet urgently if they have pale gums, are breathing fast or with an open mouth, collapse, or seem very weak. If your cat drank broth, gravy or soup containing onion or garlic, call your vet or the Animal Poisons Helpline on 1300 869 738 straight away, even if your cat looks normal. Cats that stop eating for more than 24 hours also need a vet. Do not try to make your cat vomit at home.
How vets assess and treat problems
For suspected onion or garlic exposure, your vet may check a red blood cell count and look at a blood smear for Heinz bodies, often repeating tests over several days. Early decontamination, fluids and, in severe cases, oxygen or a blood transfusion may be needed. Gut upsets are managed with supportive care tailored to your cat.
FAQ
My cat licked some chicken soup. Is that dangerous?
It depends on the soup. If it contained onion or garlic, call your vet or the Animal Poisons Helpline for advice based on how much was eaten.
Is gravy the same risk?
Many gravies and gravy powders contain onion and are salty. Do not share them with cats.
Can kittens have bone broth?
Kittens need a complete kitten diet. Ask your vet before adding anything extra.
Will bone broth help my cat's joints or gut?
There is little evidence for these claims in cats. If your cat is stiff or has digestive problems, book a vet check.
Talk with a vet
Not sure if a broth is safe for your cat, or worried about something your cat licked from a plate? A Dial A Vet veterinarian can review the ingredients with you and advise on next steps. Book a Dial A Vet consult.
References
- Merck Veterinary Manual. Garlic and onion (Allium spp) toxicosis in animals.
- RSPCA Australia Knowledgebase. What should I feed my cat?
- Quimby J, et al. 2021 AAHA/AAFP Feline Life Stage Guidelines. J Feline Med Surg. 2021;23(3):211-233.
- International Cat Care. Cats and poisons.
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.