I have recently read blogs that tell dog owners that kelp is safe for dogs. That may be misleading. I once believe it myself but have changed my thoughts on the subject after some research about a year ago.
Dr. Jean Dodds (DVM in California), recently presented on this subject at the American Holistic Veterinary Medical Conference. Her presentation was about hypothyroidism in dogs and she mentioned that iodine can suppress a dog’s thyroid function. This would include the intake of kelp and seaweed, both forms of iodine.
Commercial dog food will need iodine levels changed in order to be compliant with changing ingredient standards. My suggestion is to avoid any dog food or dog supplement that you know for a fact, contains iodine in any form.