Anyone have experience with horses with hypothyroidism, Cushing’s disease, or insulin resistance?
Posted on Sep 21, 2009 under insulin resistance treatment | 10 CommentsSorry in advance that this is so long! I started to suspect my 7 y/o paint mare was showing signs of what I thought would be hypothyroidism. I called out my vet, he has to see her for her allergies anyway and I ordered some blood work that he suggested. His initial impression was that she was hypothyroid or insulin resistant, but he made it seem like it was more of a thyroid problem than anything and didn’t even suggest that I get her tested for insulin resistance. I’m still waiting on the results of the blood work, it has been about a week and a half. I have another veterinary clinic that I trust to get a second opinion if I need to but this vet that I currently use is extremely well respected and knowledgeable so I will see what he suggests first.
When I did a little research on the subject, I found a couple of medical studies and articles that said that the normal blood panel for thyroid problem testing for T3 and T4 levels is not accurate enough to fully diagnose a horse as hypothyroid. They also go on to state that most horses that have been diagnosed as having thyroid problems are actually insulin resistant or are in early stages of Cushing’s disease and that confirmed cases of thyroid problems are extremely rare.
So…I’m not quite sure what to think now. She does show a few of the signs of Cushing’s: cresty neck, easy keeper (even though I manage her weight she does sometimes get fat deposits but they are not in strange areas on her body), sometimes lethargic (this may be related to the heat here), and has a slightly decreased immune system. I was told that vertical ridges in her hooves, weak hooves, and her mane and tail rubbing are also signs of these diseases by a friend of the family. I don’t know if there is any truth to the hoof ridges but the mane and tail rubbing also can tie in to her skin allergies and fly/mosquito allergies. She’s on antihistamines for that. She however does not drink an excessive amount (I usually have to make sure she has extra salt to encourage her to drink), does not have a thick shaggy coat or slow shedding, or abnormal urination.
Does anyone have a horse with any of these diseases who could give me any insight on if any of this sounds familiar to you and what treatments your horse is on and the cost that I would be looking at here? Any vets, vet techs, anyone with medical experience, etc that could offer some help would be greatly appreciated as well.
*Selling her is not an option because I am very afraid she would end up in the kill pen if she is diagnosed with this disease combined with her other health problems. She is very well taken care of here.*
Thank you all for your answers!
She doesn’t have the coat of Cushing’s horses. Her coat is extremely short and thin, even in winter.
I realize that the mane and tail rubbing is most likely from her allergies and fly and mosquito hypersensitivity, I had just heard that it was also related to these other diseases and was wondering if there was any truth to that. She is currently treated for the itching twice daily plus the antihistamines and for the mane and tail re-growth. The lethargy is unrelated to the antihistamines, she has always been kind of pokey (especially in summer) but she has a shiny coat and bright eyes. I wasn’t sure if this was related either.
She has access to several salt/trace mineral blocks at all times and I see her frequently licking them several times a day.
Thank you all so much for the info and links, so many great answers 
The fly and mosquito allergies are actually quite common where I live in southern Louisiana but she has other allergies as well. The climate here is horrible for animals and people with allergies, myself included. I’m miserable so I can only imagine how she feels. I’m still waiting to her from the vet on the rest of the results and from what it sounds, she doesn’t have hypothyroidism but that isn’t a surprise. I will have him come out and draw blood to do the test for the insulin resistance. He couldn’t do it from the blood he drew the other day because she hadn’t been fasting. Hopefully each problem will improve together, it seems when one disorder is off, it throws the whole body out of whack. I’m researching diet changes now to see what I can do to make small adjustments until I find out for sure if this is the problem. I don’t want to do anything major based on my hunch alone.
I also forgot to mention that I would consider selling her to someone in the Midwest or Northwest (she originally came from Iowa) where there are not so many nasty bugs, allergens, heat, and humidity as there are here. I don’t want her to suffer so it would be unreasonable for anyone to tell me that I am selfish for keeping her here because of her allergies. However, with her other health issues and that she is still relatively green broke and needs an advanced intermediate and up rider…I have valid reason to be concerned that she’d be sent to the kill pen because healthy horses are these days. Selling is not an option unless I can no longer manage her care and until I get the health concerns straightened out to where I can at least educate potential new owners on how to manage them. And to avoid that, I would rather relocate from Louisiana because I’m sick constantly and I really can’t stand the weather here either!
I have a gelding with Cushing’s and a mare with insulin resistance. The gelding was diagnosed after the vet noticed a slight crest forming on his neck. He never exhibited any shedding problems or other of the typical signs. But when he was tested, his hormone levels were all over the place. He has done so well in the years that followed, that we have retested several times, still showing the same hormonal abnormalities. My point is, a horse doesn’t necessarily exhibit all of the signs, but may still have the disease. My gelding has had the disease for several years now, and still has no coat or shedding abnormalities. He is managed with diet and Evitex (chasteberry extract). He has not needed Perolide to maintain him in good condition. Pergolide can’t be used if the horse also exhibits insulin resistance, though.
I have read the same research on diagnosing hypothyroid or hyperthyroid conditions in horses. My gelding’s thyroid levels are always off, but his diagnosis is Cushing’s. Early on he was tried on Thyrol, but it was later determined to be unnecessary. These days, I don’t think it is used very often.
You probably need further testing to come up with a diagnosis. Be aware that in the fall there is more risk of false positives since the hormone levels are altered normally during the transition to shorter periods of daylight.
In the meantime, it doesn’t hurt to restrict soluble starches in her diet, which is indicated in either condition.
One more thought on thyroid insufficiency…..I did have a hypothyroid horse decades ago, that was treated successfully by adding iodized salt to her diet. Iodine is needed to make thyroid hormones. Iodine deficiency in today’s feeds are probably rare, but could occur if the feed is grown in areas where iodine is deficient, and the feed is not fortified. If a horse was fed only hay and pasture, and both were deficient, it might be the problem. I doubt that it is the case in your situation, but is something else to consider.
My insulin resistant mare is a whole other story, and I am posting an excellent article on it that you should read before you proceed. It will give you a very good overall knowledge base for decisions on what comes next. I hope it helps.
http://www.thehorse.com/ViewArticle.aspx?ID=12588
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September 22nd, 2009 at 4:26 am
ok, i starred it so hopefully megan will see it and star it for gallop.
i know my opinion is going to be immature, so take it for what its worth.
insulin resistance is similar to diabetes, or obesity in humans. you have to watch out for things like founder and laminitis.
check out this webpage http://www.thehorse.com
it has GREAT articles that could be very interesting for you.
here’s a great article that if you dissect it, can give you little great insights and interesting facts about insulin resistance.
http://jn.nutrition.org/cgi/reprint/136/7/2094S
just hit full txt PDF and then hit begin manual download. its REALLY interesting.
good luck with your mare.
References :
i did an extensive research presentation on insulin resistance and its relation to laminitis to the nutrition Doc that reshaped utah U’s equine program. i got an A!
September 22nd, 2009 at 4:31 am
I second TheHorse.com. Great website, I recommend that anyone who isn’t already a member sign up, and get the newsletters.
I had a gelding that had Cushings. His age was a mystery, he used to be a trail horse that a friend of mine someone got, which he sold to another ‘friend’ for a couple hundred bucks. The horse was then dumped at my place. A vet looked at his teeth, and decided that he was either under thirteen-or well over twenty. He was your typical old nag.
Mainly, his problems were the hair. Way too much, I had to buy a pair of really nice big clippers for a couple hundred dollars to deal with him, and clipping him to keep him comfortable. Not clipping wasn’t an option, we lived in Phoenix, AZ and it’s hot.
He would also drink, I shit you not, over fifty gallons of water a day. I would have to fill his fifty gallon tub twice a day. He was a pain, up until the month where he got into a friend’s tub of Strongid daily wormer, and foundered in both back hooves. Just the thought of that horse stresses me out, and I can feel by blood pressure going up. ._.
I was told that the easiest way to tell if they have Cushings, is the weird coat, and the odd eating/drinking. Those are supposed to be the most common symptoms. As for the others-I have no experience, so I’ll leave them to people that do.
References :
Keeping a horse with Cushings before.
September 22nd, 2009 at 5:10 am
First of the all the mane and tail rubbing has nothing to do with either Cushings or Hypothyroidism. That is more likely to be sweet itch which is often down to mosquito bites. Best thing to do with this is to stable before dusk to after dawn and use something called Stomoxin which I do not know if you can get in America. My father worked in the pharmaceutical company which sells this and brought some home. It was originally licensed for cattle, but we used in on our horses and gave some to an owner with a mare with terrible sweet itch. To cut a long story short, the mare, with careful management, grew her mane and tail back beautifully and never got the sweet itch. The secret was to start tackling the problem before mosquitoes started to fly/bite.
Ridges on the hooves is a sign of fast growth – often happens with laminitis which would tie in with her thick crest and late on-set laminitis is tied in with early Cushings. Lethargy? Hmm. Probably more to do with the antihistamines. My horse started getting Cushings but never lost his get up and go but was thirsty, the long coat came a few years later – and to combat that we snubbed tradition and clipped him all year round. He loved that! We got some funny looks and remarks, but hey, the comfort of the horse is paramount!
From what you say she could be in the early stages of Cushings. Thirst, curly coat and frequent urination, coupled with almost insatiable hunger will come later if she is not treated now. Insulin resistance comes with Cushings. So, essentially, if she does have Cushings you also have a diabetic horse.
I have just looked up hypothyroidism and it starts very early, in foalhood and she would probably have a big swelling around the throat, the coat would be dull too.
I wish you well.
If you have more questions about Cushings I would be happy to help if you message me.
References :
Horse had Cushings.
September 22nd, 2009 at 5:56 am
I have a gelding with Cushing’s and a mare with insulin resistance. The gelding was diagnosed after the vet noticed a slight crest forming on his neck. He never exhibited any shedding problems or other of the typical signs. But when he was tested, his hormone levels were all over the place. He has done so well in the years that followed, that we have retested several times, still showing the same hormonal abnormalities. My point is, a horse doesn’t necessarily exhibit all of the signs, but may still have the disease. My gelding has had the disease for several years now, and still has no coat or shedding abnormalities. He is managed with diet and Evitex (chasteberry extract). He has not needed Perolide to maintain him in good condition. Pergolide can’t be used if the horse also exhibits insulin resistance, though.
I have read the same research on diagnosing hypothyroid or hyperthyroid conditions in horses. My gelding’s thyroid levels are always off, but his diagnosis is Cushing’s. Early on he was tried on Thyrol, but it was later determined to be unnecessary. These days, I don’t think it is used very often.
You probably need further testing to come up with a diagnosis. Be aware that in the fall there is more risk of false positives since the hormone levels are altered normally during the transition to shorter periods of daylight.
In the meantime, it doesn’t hurt to restrict soluble starches in her diet, which is indicated in either condition.
One more thought on thyroid insufficiency…..I did have a hypothyroid horse decades ago, that was treated successfully by adding iodized salt to her diet. Iodine is needed to make thyroid hormones. Iodine deficiency in today’s feeds are probably rare, but could occur if the feed is grown in areas where iodine is deficient, and the feed is not fortified. If a horse was fed only hay and pasture, and both were deficient, it might be the problem. I doubt that it is the case in your situation, but is something else to consider.
My insulin resistant mare is a whole other story, and I am posting an excellent article on it that you should read before you proceed. It will give you a very good overall knowledge base for decisions on what comes next. I hope it helps.
http://www.thehorse.com/ViewArticle.aspx?ID=12588
References :
RN and 57 years with horses
September 22nd, 2009 at 6:26 am
My donkey was FINALLY diagnosed with hypothyroidism.
His symptoms were balding over his hips and down legs. He has a cresty neck. He wasn’t lethargic. He was an easy feeder as all donkeys are lol.
He is on Thyrol, and it took 4 mths to see improvement. It took the full 4 mths for his hair to grow back, he had such horrible skin damage from trying to figure out for 2 yrs what was going on with him.
Thats all my experience with this so far, good luck and hopefully you find out what is going on!
References :
September 22nd, 2009 at 7:11 am
I had a pony with cushings, fortunatly he wasnt at a stage where it was severe and I could manage his symptoms by managing his diet.
The big tip off was the cresty neck, which was discovered when I body clipped him becasue he wasnt shedding properly (another red flag). It was infact this picture that was the tip off-
http://i299.photobucket.com/albums/mm287/Bindi72003/102_1102.jpg
I read in a report (cant find it now?) that cushings symptoms come from a tumour in the base of the brain, which slowly grows and cuts off the supply of whatever manages the insulin. The tumor will slowly grow over the horses life time till its big enough to be fatal. Ponies are more suseptable to it but why it happens is unknown.
Usually ponies with cushings dont drink enough water and become dehydrated, so the mineral block youve got is great, it’ll encourage her to drink.
My pony inparticular would become lerthargic, lazy and sick if he ate sugar, including the new shoots of grass that sprout after rain or during spring, so I had to completely cut out all sugar from his diet, and he improved immediatly. His body wasnt able to process the sugars properly and it would be deposited all over his body in lumps of fat. Luckly he never got close to foundering but I was on founder watch everyday and its not a great feeling.
He had his good days and his bad days, some days he was full of energy, others he was very lerthargic and would fall alseep often.
There is a new drug you can buy, its a pill which will help the horses symptoms, but it wont actually do anything for the disease. I do hope your mare doesnt have cushings, its not a nice way to watch your horse battle with a disease such as this one.
References :
September 22nd, 2009 at 7:24 am
I currently have two horses with advanced Cushings, and I had another with it some years ago.
The symptoms can vary all over the place.
The one mare had the cresty neck, the increased fur coat, and a suppressed immune system – she got such a bad case of thrush it went into the plantar cushions. I put her on the Pergolide, which obviously helped her immune system as she threww off the thrush very, very quickly after that. She also has her lethargic times, especially lately, as she has actually developed narcolepsy – that’s where they suddenly fall asleep, and may even fall down.
The other mare hasn’t got the crest, or the fur coat. She’s shinier and nicer looking there then she has ever been. She got the huge hay belly (looks pregnant with twins and ready to pop) and a terrible tendency to founder at the drop of a hat. Put her on Pergolide as well, and she hasn’t foundered since.
I had an old gelding with all the symptoms – long, long curly coat, cresty neck, fat deposits – back before Pergolide was available. He eventually died of neurological issues (seemed to have a stroke).
None of these horses drank/drink as uch as normal.
I also have an old pony with insulin resistance. He gets fat easily, he founders easily, and his coat doesn’t shed. He started this way at around 8 years old. We handle it via diet.
My vets did not do blood tests for their diagnoses. They started them on the Pergolide and when the horse improved their diagnosis was confirmed. They said the blood tests weren’t definitive and were expensive and unnecessary. (Just passing it on, not judging your vet!) As this was years ago, the tests may be better now.
The two still living mares have done beautifully on Pergolide for several years now.
Cushing’s is caused by a tumor on the pituitary, and it will eventually get them (as my mare’s narcolepsy shows, it’s still growing, pressing on the brain and throwing their chemicals off) but in the meanwhile they have an excellent quality of life in their retirement. They’re both over 30.
Your mare seems to have multiple issues, but it certainly sounds like Cushings is one of them. THese diagnoses are always difficult to make, as medicine is often as much an art as a science, and this is especially complicated when there are multiple issues. I think I’d want her tested for Cushings too, as it is treatable and more common than the hypothyroidism or insulin resistance.
Because of her age, which is more like my insulin resistant pony, it’s probably that – she’s young for Cushings. Many of the syptoms are very similar between Cushing’s and insulin resistance. I have no experience in horses with hypothyroidism.
Unfortunately, I’ve never hear of allergies, particularly fly allergies (which are extremely difficult to treat), being caused by any of these, or improved by treating for any of these.
Poor horse. I hope you can get her feeling better.
References :
September 22nd, 2009 at 8:08 am
I had to have a 14 year old registered Peruvian mare put down with cushings a few years ago.. Please go to the barefoot timmers site on the internet . They have wonderful information on cushings that i wish I had known about years ago. Good luck with your mare.
References :
Experience
September 22nd, 2009 at 8:38 am
Find a chinease traditonal medicine vet
I know someone that had someone treat their horse with Cushings and had a lot of success- unfortunately I found aboud this too late for my pony that had Cushings
References :
September 22nd, 2009 at 9:19 am
Your research is correct, hypothyroidism that isn’t secondary to some other medical condition is extremely rare in horses. So, if your vet is suspecting hypothyroidism but isn’t looking for a cause you really want to discuss this with him or go ahead with a second opinion. At 7 years old, Cushing’s disease isn’t highly likely so Insulin Resistance is what you should really focus on initially. It fits the symtpoms. Your vet can run a simple screening test for this by drawing a single blood sample after your horse has been fasted for 12 hours and sending it off for a resting serum insulin test. It sounds like you are getting that one done which is good.
The itchiness is probably a matter of insects and the hoof ridges don’t sound like they are indicative of a problem, but more likely normal hoof growth. If there were hoof pain and really odd and prominent ridges then it would be a concern. Your use of antihistamines and a change in season may resolve the itching problem.
As for treatment of IR, it’s more a management issue. Dietary changes should be made (and can be made for any horse regardless of having a diagnosis or not) to ensure that the diet consists of feedstuffs that are less than 12% nonstructural carbohydrates (NSC). Hay should be tested for NSC content or soaked for 30 minutes in cold water prior to feeding. Hays should also be warm season grasses as these tend to be lower in NSC content to begin with. Testing hay for NSC content is done by Dairy One Forage Lab and you can find their information online. Pasture access should be limited to 2 hours a day or only with a grazing muzzle on. Supplemental protein, vitamins and minerals should be supplied in the form of a "ration balancer"—a supplemental feed that is designed to balance the nutrient content of hay diets and is usually fed at a rate of 1-3 lbs per day. (A list of ration balancers is at the bottom)
Daily exercise is also very important for these horses to help maintain a good weight and fitness level. So if you can’t work her daily she at least needs turnout where she can move around. But daily work in hand or under saddle would be best.
http://www.thehorse.com has wonderful resources on insulin resistance for you to check out
Buckeye Gro N WIn or ALf Gro N Win
http://www.buckeyenutrition.com/dealers.html
Kent Horsego12 or Horsego32
http://www.kentequine.com/Results.aspx
LMF SuperSupplement
http://lmffeeds.com/cart/index.php?m…products_id=10
Progressive Pro Advantage grass or alfalfa formula
http://prognutrition.com/DealerLocator.htm
Purina Enrich32 or Enrich12
http://horse.purinamills.com/dealerlocator/
Seminal Equalizer
http://www.seminolefeed.com/ProductS…/Equalizer.mht
Triple Crown TC12% or TC30% supplement
http://www.triplecrownfeed.com/distributors.php
Brookes Feed All Phase
http://www.brooksfeeds.com/product04a.html
ADM Allaince Nutrition Gro STrong
http://www.admani.com/AllianceEquine…lsVitamins.htm
TDI-30
http://www.tdihorsefeeds.com/product.asp#TDI-30
References :
Registered Veterinary Technician
work at an equine hospital