Cats won't be harmed if they eat a few small pieces of seaweed. Seaweed contains a lot of vitamins, trace elements and minerals, especially selenium and iodine, which can supplement the nutrients needed by cats. However, because seaweed has a high salt content, feeding cats too much can put a burden on their kidneys, so it should not be given in large quantities.
Cats are obligate carnivores, while seaweed is a type of food made from laver through various processing methods. Such non-meat foods are almost never on a cat's diet.
