Kelp is just one of a variety of seaweed that can be used for supplementation.
It is also one of the most commonly referred to dietary supplements and easy to find. If you need an online source try Pet Herbs Direct
Aside from the iodine, which in moderation can be a wonderful thyroid support supplement, seaweed also provides many other health benefits including vitamins and minerals. Further, it lowers cholesterol. I’m finding that benefit with a lot of herbs.
But please understand that a ton of kelp or seaweed in your dog's diet can do more harm than good. More is not necessarily better.
Yup, I do love how Mother Nature does multiple things with one plant (though, technically, it is not a plant). If you continue to read all the supplements and herbal remedies on this website, you’ll notice that most natural foods do just that. Seaweed is definitely one of them.
Seaweeds are especially rich in calcium and iodine. They also supply chromium (essential for glucose utilization), zinc (for collagen strength and healthy skin), iron, potassium, copper, sulphur, silver, tin, zirconium, phosphorous, and silicon (crucial to skin elasticity), magnesium, manganese, boron, bromides, and other trace minerals.
Kelp also kills parasites, (as in intestinal worms) and is an antiprotozoan. (Does Giardia and Coccidia ring a bell? They are protozoans).
While I have not been able to find any documentation as to which worms or protozoans they destroy it certainly is worth adding it to the arsenal of supplements at home.
I could find only one study from the 1946 Philippine Medical Journal which reported the use of seaweed as an anti-helmintic, (kills intestinal worms) It was found to be 73% effective and non-toxic. I do have to say I love hearing the term "nontoxic" with natural foods used in moderation.
Normal dosage is about 1/4 to 1 tsp per day. I give 1/4 tsp per pup . I now mix the seaweed blend in with a few other natural food supplements that aid in repelling parasties or all kinds.
Being a little OCD, I prefer to use a blend of seaweed that contains 7 different types of varieties. Why not expand your kelp supplements to include a few more varieties? You can buy that seaweed blend here.