this is a product i have used in the past and now renewed using on my performance horses

Good ole Source..you forget about then come back to and wonder why you ever quit using it to begin with.

Yes, your horse needs iodine, and unless you feed iodized salt in a rather large quantity every single day or otherwise feed major and mineral minerals containing iodine, your horse isn't getting the minimal amount needed. We don't see iodine in hay in California. See the National Research Council's recommendations for the amount. This is an easy and cost-effective way to provide this essential nutrient. Mix it with plain salt and a handful of hay pellets or supplement the iodine provided in iodized salt if you can do a little math. If you think a salt block will do the job, then try measuring the weight of your salt block at the beginning of the month and at the end of the month and calculate intake. I bet you'll be surprised.

Been using it for years on the dogs.

I've used this in the past and have never been disappointed. Shiny coats, strong hooves and the horses love it. Great value for a great product.