Updated 2026-08-07 · Source: VCA Animal Hospitals — pet health library · Free · No sign-up
Not toxic, but be careful — seaweed and nori isn't poisonous to cats, and it comes with caveats that matter.
If your cat may have eaten something harmful — or any part of a lily — call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 right now — don't wait for symptoms. A consultation fee may apply to the ASPCA hotline.
Verdict for cats
Caution
Severity
2 / 5 — Mild — usually stomach upset; watch them.
Safe amount
A taste at most
Category
Human snacks
Source
VCA Animal Hospitals — pet health library · reviewed 2026-08-07 · confidence: medium
Why
Plain nori is not toxic to cats and some like it, but seasoned snacks are salty and often contain Allium. Beach seaweed is unsafe for cats too.
Signs to watch for if your cat has eaten seaweed and nori
Drinking and urinating far more than usual
Vomiting and diarrhea
Wobbliness or weakness
Tremors or seizures at high intake
Signs vary with the amount and with the individual pet, and some appear only after a day or more. Their absence does not mean your cat is in the clear — call rather than watch.
What to do now
Don't make it a habit. Watch for vomiting, diarrhea or a lost appetite over the next day and call your vet if it doesn't settle or your cat seems unwell.
Never induce vomiting and never give any medicine unless a vet tells you to. With some substances it causes more damage than the poison. This page tells you when to get help — it never tells you how to treat at home.
Safer treats made for cats
If you're sharing food because you want to treat them, a treat formulated for cats does the job without the guesswork.
Verdicts are transcribed from the cited veterinary sources, never inferred. Where a source establishes a finding for one species only, the other species is left null and the page says to ask your vet — a dog finding is never copied onto a cat.
This page is a reference, not veterinary advice or a diagnosis. CanMyPetEat is a reference, not veterinary advice or a diagnosis. It tells you when to get help — never how to treat at home. Never induce vomiting or give any medicine unless a vet tells you to. Individual pets vary and toxicity guidance changes; your vet and the ASPCA Animal Poison Control Center are the authority.
Not toxic, but be careful — seaweed and nori isn't poisonous to cats, and it comes with caveats that matter. Plain nori is not toxic to cats and some like it, but seasoned snacks are salty and often contain Allium. Beach seaweed is unsafe for cats too.
What happens if a cat eats seaweed and nori?
Watch for: Drinking and urinating far more than usual; Vomiting and diarrhea; Wobbliness or weakness; Tremors or seizures at high intake. Signs can take hours or, for some poisons, a day or more to appear, so call your vet rather than waiting to see.
How much seaweed and nori is dangerous for a cat?
The safe amount is a taste at most, as an occasional treat rather than a daily habit. Large amounts mainly cause stomach upset; if that doesn't settle within a day, call your vet.