Iodine in Horses

Feeding Horses iodine supplements

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Enlarged thyroid in 25 year old horse

I have a 25 year old Arabian horse with an enlarged thyroid. I am looking for a supplement fir him because he looks old. Poor body weight, and coat.

Robert Konopka 156 days ago

iodine for older horses

I have an Arab mare, 28 years and Tennessee Walker gelding, 22 years. For past several years have struggled with scratches infection/reinfection with my mare. Have had vet out for oral antibiotic treatment, topical salves, anti fungal shampoos and a whole long list of more treatments. Infections are severe worsening as each year goes by. Last winter, had to fight scratches through winter as well in warm season. My gelding had a walnut size thyroid goiter when I bought him at 9, and last year it began growing and is now large lemon size. I have been very frustrated with my horse's health and commented that they must have age-related immune system defective functioning. I feed Tripple Crown, Senior. They have free choice mineralized salt 70ppm. I always believed my feed/salt was taking care of my horses' iodine needs. But I have a lot of white clover and boy have they drooled their way through summer pasture. I read that skin problems, thyroid problems, immune system problems can be related to low iodine intake in humans and I began asking around my horse people if anyone heard of supplementing iodine. My local organic feed livestock expert tells me that supplementation is needed in some cases and recommended kelp, 1-2 oz as a top dressing. My mare's skin cleared up after a week on the kelp. After 3 weeks my gelding's goiter seems to be slightly reduced... will need to continue watching this. My farrier told me he was aware that old farm folks in his routes used to supplement iodine for health problems with horses. He says modern vet schools totally dis non-pharmaceutical treatments. Because of how much white clover my horses consume, and with everything else I've experienced... real health issues that did not respond even to really great vetting and huge bills... a couple of my vet bills exceeded $800 with site care and prescriptions per visit! I am amazed that there is so little information on iodine supplementing for horses other than for pregnant mares. It seems that there is no proactive use only use after the fact of symptomatic evidence of iodine deficiency. Is there older, not modern, information about iodine for horses? I do not want iodine toxicity... but I do want healthy horses!

Gail L Turnbull more than 2 years ago

Goiter TWH 21 Gelding too.

Hi Gail My geldings story is spot on with yours, in the last 24 hrs he is colicky too.. Vet checked this a.m. with no other symptoms..... Bute was admined as he is displaying a fairly rough gate. Curious how your TWH is doing with seaweed supplements? We live in Bend, Oregon so high desert climate and weather is changing quick.

Ronda HalvorsenFerns more than 1 year ago

Iodine in equine supplements

Thank you for your post...I thought I was alone in this...My vet said to reduce to a tablespoon a pony went lame in January ….I went on Seaweed again and he improved and then I added a much reduced 1/4 to 1/2 cup of seaweed a day...tope dressing on his feed out in a field where he could move to the next pile with grain and he always chooses the seaweed pile...Now putting git out freestyle in a bucket. One pony picks at it the yearling eats it for a bit and my older cushings guy thrives on it.....eats the pail....

Melany Moore more than 1 year ago

Iodine for Horses/Iodine for Cows

I've been studying human needs for iodine for the last 8 years or so. Our website ( has numerous posts on iodine for human beings. HOWEVER.... as a "large animal enthusiast" (I took care of a stable of 40 horses for 2 summers when I was going to college in Cambridge MA), I've looked quite carefully into this issue. We horse-lovers have a lot - really a LOT - to learn from the cow folks. It is a well-established veterinary fact that an (average) 1,000-lb. cow needs 12 mg (milligrams) of iodine daily in order to calve properly and provide adequate nutritional lactation to the offspring. I suspect it is PRECISELY THE SAME for horses (someone please tell me I'm wrong, as I surely could be). On a calculated basis, this works out to about 2 mg/day for human beings.... To put that in perspective, the current "human" Recommended Daily Allowance is 0.150 to 0.250 mg. Ridiculous! Why? Because the RDA was set in 1924, when we had NO IDEA of the human body's true and comprehensive need for iodine in every organ and tissue in the human anatomy. We believe that 1-2 mg/day for humans is the minimum # required (and, interestingly, the endocrinologists unequivocally say that at 1 mg/day (and even at 2 mg/day) there has NEVER been noted an adverse reaction.The same is very very likely to be true for horses as it is for humans and cows. I would urge you to try, for a week at least, adding a solution of water with 12 mg/iodine - as potassium iodide - to your horse's feed. You'll likely see a difference - if there WILL be a difference - within a week, maybe 2 at most. Mood, alertness, sleep patterns, skin quality, general happiness - all should improve rapidly. It happens in humans, I'll bet it happens in horses. As one of the top iodine specialists in the world (on the WHO/UN council for iodine deficiencies) - Dr. Michael Zimmerman - says, "The dangers of excess iodine are far outweighed by the problems of iodine deficiency." Especially during pregnancy and pre-pregnancy. And really for both sexes. Kindly let me know if this works for you. IF YOU WANT SOME FREE IODINE i'll happily send it. Just write me. I'll send a bottle of our stuff, and you'll need only 24 drops of iodine to equal 12 mg (each drop being 500 micrograms, or 1/2 mg.). Oh - I wrote a blog today on cows and iodine. It's on our website under "Blogs."

Eugene Rosov 309 days ago


I have been researching lately about iodine in humans (I have breast cancer). I'm realizing that we need much more than modern science suggests. Today, I found 2 of our horses lame, with scabby bumps below the hocks/knees. this looks like scratches. We have moved to TN and it is much wetter here than our previous home in northern Indiana. I do believe that this outward symptom is from an internal deficiency and I suspect iodine. I read your post above and wondered about your iodine supplement offered. I cannot seem to find anything for internal use for horses on any of the veterinary websites. I have some Lugols 2% iodine for myself in dropper bottles. Each drop contains 2.5 mgs. So, following your instructions for cows, each horse would get approximately 5 drops per day. Please tell me the address to your website and blog and if you sell iodine for horses. Thank you.

Michelle Riley 26 days ago

Mare in ring