By Dial A Vet Veterinary Team
Last updated: 30 October 2026
Goldfish crackers are a lunchbox favourite, and the little fish shapes scatter across car seats and couches. Cats may bat them around or crunch a few. The fish shape is just a name, though. These are cheesy wheat crackers, and the seasoning includes one ingredient that matters for cats.
Key takeaways
- Pepperidge Farm lists onion powder among the ingredients in Cheddar Goldfish.
- Onion damages red blood cells in cats, and cats are the most susceptible species. Signs can take several days to appear.
- One or two crackers are unlikely to cause harm. A larger amount, or a cat that eats them often, is worth a call to your vet.
- The crackers are also salty and cheesy, which can upset the stomach.
- Do not make your cat vomit at home. Call your vet or the Animal Poisons Helpline on 1300 869 738 for advice.
What is in Cheddar Goldfish?
Pepperidge Farm lists enriched wheat flour, cheddar cheese (with annatto colour), vegetable oil and salt, followed by smaller amounts (2 percent or less) of yeast, sugar, autolysed yeast extract, paprika, spices, celery, onion powder and baking soda. A 30 g serve is about 55 crackers.
So a single cracker weighs roughly half a gram, and onion powder is a minor ingredient. That is reassuring for one or two crackers. It is less so for a cat that has eaten from an open bag.
Why onion powder matters for cats
The Merck Veterinary Manual explains that onion and garlic contain sulphur compounds that damage red blood cells, leading to Heinz body anaemia. Merck notes that:
- cats are the most susceptible species
- concentrated forms, such as dehydrated powders, are most often involved
- toxicosis has been reported in cats after less than a teaspoon of cooked onion
- red blood cell breakdown typically happens three to five days after exposure
The label does not say how much onion powder is in each cracker, so your vet will weigh the amount eaten against your cat's size. Read more in our onions guide.
Salt and cheese
Salt and fatty foods are on the RSPCA list of foods to avoid for cats. The ASPCA notes that large amounts of salt can cause thirst, increased urination, vomiting, diarrhoea, tremors and seizures. A few crackers are nowhere near that, but they can still cause a tummy upset. Cheese adds dairy, and the ASPCA notes pets do not have much lactase, so dairy can cause diarrhoea.
Signs to watch for
In the first day:
- vomiting or diarrhoea
- drinking more than usual
Over the next several days, if a larger amount was eaten:
- lethargy or weakness
- pale or yellow-tinged gums
- fast breathing or tiring easily
- dark or reddish urine
What to do now
- Count or estimate how many crackers are missing.
- Keep the packet so you can read the label to your vet.
- If more than one or two crackers were eaten, call your vet or the Animal Poisons Helpline on 1300 869 738.
- Do not make your cat vomit unless a vet or the Helpline tells you to.
- Watch your cat closely for the next week, as anaemia can be delayed.
When to see a vet urgently
- weakness, collapse or breathing changes
- pale or yellow gums, or dark urine
- repeated vomiting
How vets approach it
If a meaningful amount of onion may have been eaten, your vet may suggest blood tests to check the red blood cells, sometimes repeated over several days. Treatment depends on what the examining vet finds.
Safer snacks for your cat
- small pieces of plain cooked chicken or fish
- freeze-dried meat treats for cats
- a few pieces of your cat's usual dry food used as a reward
Cornell's Feline Health Center recommends keeping treats to 10 to 15 percent of daily calories.
FAQ
Are other Goldfish flavours safer?
Not necessarily. Pizza Goldfish also list onion powder, and flavoured varieties can have more seasoning. Always check the label. See our guide to pizza Goldfish crackers.
My cat ate one cracker off the floor. Should I worry?
One cracker is very unlikely to cause problems. Keep an eye out for vomiting and call your vet if anything seems off.
Why does my cat like them?
It may be the cheesy smell, or simply the fun of batting a small cracker around. Either way, offer a cat treat instead.
Talk with a vet
If your cat got into the snack drawer and you want help weighing the risk, a Dial A Vet veterinarian can talk it through with you. Book a Dial A Vet consult.
References
- Pepperidge Farm Goldfish. Cheddar Baked Snack Crackers.
- Pepperidge Farm Goldfish. Pizza Baked Snack Crackers.
- Merck Veterinary Manual. Garlic and Onion (Allium spp) Toxicosis in Animals.
- RSPCA Knowledgebase. What should I feed my cat?.
- ASPCA Animal Poison Control. People Foods to Avoid Feeding Your Pets.
- Cornell Feline Health Center. Feeding Your Cat.
- Li X, et al. PLoS Genet. 2005;1(1):e3. Pseudogenization of a Sweet-Receptor Gene Accounts for Cats' Indifference toward Sugar.
- Animal Poisons Helpline (Australia, 1300 869 738). Animal Poisons Helpline | 24/7 Pet Poisoning Advice.
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.