This article from Dogs Naturally Magazine (check them out) explains that seaweeds are the best green foods for dogs as, besides being super nutrient dense, their cells are not surrounded by cellulose which is difficult for dogs to digest. They are thought to boost the immune system, promote longevity and may help in reducing cancer.
Natural health guru, Dr Edward Group, shares 8 health issues to keep in mind with regard to iodine deficiency in dogs. He notes seaweed has an abundance of naturally occurring iodine making it a great way to boost your dog’s nutrition, and the 48% reduction in dog cancer since 1982 when iodine was introduced in commercial dog foods.
This paper discusses iodine intake requirements for humans, dogs and cats. It notes that dietary iodine is around >90% bioavailable compared to synthetic supplements, which are variable. It concludes that “Chronic iodine excess or deficiency may result in clinical disease” and that intake should be consistent. It’s complex!