Can cats eat mustard? No — why, and what to do
Quick answer: No — mustard is not safe for cats and should never be given.
Quick verdict
Unsafe
Key risk
Mustard seeds cause stomach upset and the condiment is salty and spicy.
Why
Mustard is toxic to cats and must be avoided.
Keep mustard out of reach
Tarhong Concentric Circle Slow Feeder Bowl for Dogs & Cats
A stylish slow-feeder bowl that encourages healthier, calmer mealtimes — available in blue, grey, or white.
£14.99
LickiMat Felix & Casper Slow Feeder Mats for Cats
Whisker-friendly flat feeding mats that slow mealtimes, reduce stress, and keep cats mentally engaged — freezer and microwave safe.
£10.99
Simple Solution Extreme Stain & Odour Remover Cat
A 500ml concentrated enzyme spray for stubborn cat urine, vomit and faeces stains
£8.65
Moderna Cat Litter Linerbags
A fitted liner bag for Moderna's Large litter tray, sized to the tray's own shape
£6.99
Can cats eat mustard, and why?
Mustard is toxic to cats and must be avoided. Mustard seeds cause stomach upset and the condiment is salty and spicy.
Cats are obligate carnivores: they must get most of their nutrition from meat and need nutrients such as taurine that only animal products provide. They lack some enzymes for processing plants and carbohydrates, so fruit and veg offer little benefit and can upset their stomach; many cats are also lactose intolerant.
Warning — what to watch for
Mustard seeds cause stomach upset and the condiment is salty and spicy.
If your cat has eaten mustard, don’t wait for symptoms — contact your vet immediately, or call the Animal PoisonLine on 01202 509000 (24/7, UK). Signs of a problem can include vomiting, diarrhoea, drooling, lethargy, tremors or loss of appetite.
🚨 Find an emergency vet near youMore foods cats might eat
More for cats
If your cat has eaten mustard, ring your vet — do not wait to see what happens. For preventing a repeat:
Mason Cash Meow Cat Bowl
A 13CM angled stoneware cat bowl with a 300ml capacity for comfortable meals
£5.99
Ancol Curved Cat Dish
Shallow ceramic cat dish with curved edges to keep food centred and whiskers clear
£5.79
Tarhong Flower Cats Melamine Cat Bowl
A pretty, fuss-free cat saucer that's BPA-free, break-resistant, and pops straight in the dishwasher.
£10.99
Feeding & nutrition guides
Frequently asked questions
Can cats eat mustard?
Unsafe. Mustard is toxic to cats and must be avoided.
What happens if my cat eats mustard?
Mustard seeds cause stomach upset and the condiment is salty and spicy. If your cat has eaten mustard, contact your vet or the Animal PoisonLine (01202 509000) straight away — don’t wait for symptoms.
Is mustard poisonous to cats?
Unsafe. Mustard is toxic to cats and must be avoided.
Free printable: safe & toxic foods for cats
mustard is just one food — get the full one-page checklist of what’s safe, fine in moderation, or dangerous for cats. Vet-sourced, yours to print and keep.
Check mustard for another pet
Sources
Our verdict on whether cats can eat mustard draws on established UK and US veterinary and welfare organisations. Individual pets, quantities and preparation vary — always confirm with your own vet.