How long does it typically take for elevated insulin levels to begin to drop?


I have a ~20yr 42" pony that just tested with very high insulin levels (350 uU/ml with glucose 77mg/dL at blood draw 11/9/20). The only clinical indications of a problem were lethargy and then muscle tightness when he started walking slowly and stiff legged. No laminitis or change in appetite thus far but the pills have been a challenge to get in him.

I have been treating him as if he was IR for the 7 years I have owned him - dry lot, no grass, no treats, tested second cutting timothy (ESC 8.2 and starch .1 by dry matter)  weighed out and fed 5 times per day in slow feeders, balanced with California Trace and loose iodized salt. No hay or feed changes since March 2020. He started to slow down around the beginning of October and then rapidly slowed down about ten days ago when the blood was pulled so I was really thinking about the seasonal rise even though he has never shown signs of this before. I started soaking his hay in hot water (45min) on 11/11/20 and he was put on metformin at that time as well (5, 1000mg pills twice daily). He is not laying down as much but otherwise I have seen little further improvement and my vet has given me no guidance or parameters for retesting his blood or what to expect during this process. His ACTH came in as 65 pg/mL but the vet did not feel this was indicative of Cushings and believes it is EMS.

Wondering if I should have seen more results from the metformin and soaked hay by now or if there are other things I should be doing to help him. I retested the hay and sent it off to Equi-Analytical thinking maybe its actually higher in sugar than I thought and my previous test wasn't accurate.

Feeling pretty lost. He is still bright eyed and really trying so I want to help him the best I can. Anyone else have a similar experience with high insulin and no laminitis or confirmed Cushings diagnosis? How long does it typically take for elevated insulin levels to begin to drop and clear itself from the body? Vet drawing blood this Friday (CBC) to check Liver and Kidney status - is there anything else I should be testing for?

Thanks in advance. :)
Eileen Towner in Western Washington state 2020

Sherry Morse

Hi Eileen,

You'll get a full welcome message shortly but a couple of things jump out at me - first, while the hay is below 10% ESC+starch we have a number of horses on the list who can't handle hay with ESC+starch as high as what's in your hay and soaking the hay can help with that. 

Have you had x-rays done since this episode started?  How was 'no laminitis' diagnosed?  Just because a horse or pony is not in the classic laminitis stance does not mean that they are not experiencing pain in their feet and walking slowly and stiff legged and laying down are pretty good indications that something is going on with their feet that could be a problem. 

An ACTH of 65 at this time of year when we're at the tail end of the rise would still be a red flag for me and I'd want to start him on Prascend or Pergolide to try to get that back into a more normal range.  You can read more about the weekly/monthly expected cutoffs here:  Elevated ACTH can drive up insulin so while getting the diet tight is one piece of the puzzle, making sure ACTH is controlled is another.

If you could get a case history posted to the folder you've created as well as create a photo album and add pictures of Cody as well as any x-rays you may have we can offer more advice but the most important thing to remember is that this is a marathon, not a sprint. Diet changes will help, but he may need better ACTH control and trim corrections to really make him comfortable.


Hi Eileen,

Here is the promised welcome message from the ECIR group with lots of information to satisfy your curiosity and stimulate some more questions.  I notice in your signature that you have added the address of the folder you’re going to use to store your case history and other information.  That’s a great start!  The link to the folder is not active and that may be intentional until you have something in there for us to read.  At that point, you want to activate it by pressing ‘Return’ after the address and then ‘Save’.  Then it will turn blue.  Looking forward to learning more about Cody in your case history.

Welcome to the group! 

The ECIR Group provides the best, most up to date information on Cushing's (PPID) and Insulin Resistance (IR). Please explore our website where you'll find tons of great information that will help you to quickly understand the main things you need to know to start helping your horse. Also open any of the links below (in blue font) for more information/instructions that will save you time.

Have you started your Case History? If you haven't done so yet, please join our case history sub-group. We appreciate you following the uploading instructions so your folder is properly set up with the documents inside. Go to this CH message with info on how to use various devices and forms. If you have any trouble, just post a message to let us know where you are stuck. 

Orienting information, such as how the different ECIR sections relate to each other, message etiquettewhat goes where and many how-to pages are in the Wiki. There is also an FAQs on our website that will help answer the most common and important questions new members have. 

Below is a general summary of our DDT/E philosophy which is short for Diagnosis, Diet, Trim and Exercise.


DIAGNOSIS: There are two conditions dealt with here: Cushings (PPID) and Insulin Resistance (IR). These are two separate issues that share some overlapping symptoms. An equine may be either PPID or IR, neither or both. While increasing age is the greatest risk factor for developing PPID, IR can appear at any age and may have a genetic component. Blood work is used for diagnosis as well as monitoring the level of control of each.

PPID is diagnosed using the Endogenous ACTH test, while IR is diagnosed by testing non-fasting insulin and glucose.

The fat-derived hormone leptin is also usually abnormally elevated in insulin resistance but because there are many other things which can lower or increase leptin ECIR is not recommending routine testing for this hormone. Leptin is the hormone that says "stop eating". 

In Europe, adiponectin is tested instead of leptin. Adiponectin helps regulate glucose and fat burning, and maintain insulin sensitivity. Low levels are associated with EMS. It has come to be preferred over leptin because it is not influenced by things like weight or exercise, and also because it was the only factor other than insulin levels that predicted laminitis risk

*Before calling your vet to draw blood for tests, we suggest saving time and wasted money by reading these details and then sharing them with your vet so that everyone is on the same page regarding correct testing and protocols.

*Please remember to request copies of the results of all the tests done rather than just relying on verbal information. Your vet should be able to email these to you. If you have previous test results, please include those as well. All should go in your CH, but if you are having any trouble with the CH, just post in the messages for now. 

Treatment: IR is a metabolic type - not a disease - that is managed with a low sugar+starch diet and exercise (as able). The super-efficient easy keeper type breeds such as minis, ponies, Morgans, Arabs, Rockies are some of the classic examples. PPID is a progressive disease that is treated with the medication pergolide. Some, but not all, individuals may experience a temporary loss of appetite, lethargy and/or depression when first starting the medication. To avoid this "pergolide veil" (scroll down for side effects), we recommend weaning onto the drug slowly and the use of the product APF. The best long term results are seen when the ACTH is maintained in the middle of the normal range at all times, including during the annual seasonal rise. To accomplish this, the amount of medication may need to increase over time. Neither condition is ever "cured", only properly controlled for the remainder of the equine's life. If your partner is both PPID and IR then both medication and diet management will be needed. 

DIET: Almost all commercial feeds are not suitable - no matter what it says on the bag. Please see the International Safe Feeds List for the safest suggestions.

No hay is "safe" until proven so by chemical analysis. The diet that works for IR is:

  • low carb (less than 10% sugar+starch)
  • low fat (4% or less) 
  • mineral balanced  

We use grass hay, tested to be under 10% ESC + starch, with minerals added to balance the excesses and deficiencies in the hay, plus salt, and to replace the fragile ingredients that are lost when grass is cured into hay, we add ground flax seed and Vitamin E. This diet is crucial for an IR horse, but also supports the delicate immune system of a PPID horse. 

*Until you can get your hay tested and balanced we recommend that you soak your hay and use the emergency diet (scroll down for it).  The emergency diet is not intended for long term use, but addresses some of the most common major deficiencies. Testing your hay and getting the minerals balanced to its excesses and deficiencies is the best way to feed any equine. If you absolutely cannot test your hay and balance the minerals to it, or would like to use a "stop gap" product until you get your hay balanced, here's a list of "acceptable" ration balancers

There is a lot of helpful information in the start here folder so it is important you read all the documents found there. The emergency diet involves soaking your untested hay for an hour in cold water or 30 minutes in hot water. This removes up to 30% of the sugar content, but no starch. Starch is worse than sugar since it converts 100% to glucose while sugar only converts 50%, so starch causes a bigger insulin spike. Make sure you dump the soaking water where the equine(s) can't get to it. 

What you don't feed on the IR diet is every bit as, if not more important than, what you do feed! No grass. No grain. No sugary treats, including apples and carrots. No brown/red salt blocks which contain iron (and sometimes molasses) which interferes with mineral balancing, so white salt blocks only. 

No products containing molasses. No bagged feeds with a combined sugar and starch of over 10% or starch over about 4%, or fat over about 4%. Unfortunately, even bagged feeds that say they are designed for IR and/or PPID equines are usually too high in sugar, starch and/or fat. It’s really important to know the actual analysis and not be fooled by a name that says it is suitable for IR/PPID individuals.

We do not recommend feeding alfalfa hay to IR/PPID equines as it makes many of them laminitic. Although it tends to be low in sugar, many times the starch is higher and does not soak out. Additionally, protein and calcium are quite high, which can contribute to sore footedness and make mineral balancing very difficult.

TRIM: A proper trim is toes backed and heels lowered so that the hoof capsule closely hugs and supports the internal structures of the foot. Though important for all equines, it's essential for IR and/or PPID equines to have a proper trim in place since they are at increased risk for laminitis. After any potential triggers are removed from the diet, and in PPID individuals, the ACTH is under control, the realigning trim is often the missing link in getting a laminitic equine comfortable. In general, laminitic hooves require more frequent trim adjustments to maintain the proper alignment so we recommend the use of padded boots rather than fixed appliances (i.e. shoes, clogs), at least during the initial phases of treatment.

Sometimes subclinical laminitis can be misdiagnosed as arthritis, navicular, or a host of other problems as the animal attempts to compensate for sore feet. 

You are encouraged to make an album and post hoof pictures and any radiographs you might have so we can to look to see if you have an optimal trim in place. Read this section of the wiki for how to get a hoof evaluation, what photos are needed, and how to get the best hoof shots and radiographs.

EXERCISEThe best IR buster there is, but only if the equine is comfortable and non-laminitic. An individual that has had laminitis needs 6-9 months of correct realigning trims before any serious exercise can begin. Once the equine is moving around comfortably at liberty, hand walking can begin in long straight lines with no tight turns. Do not force a laminitic individual to move, or allow its other companions to do so. It will begin to move once the pain begins to subside. Resting its fragile feet is needed for healing to take place so if the animal wants to lay down, do not encourage it to get up. Place feed and water where it can be reached easily without having to move any more than necessary. Be extremely careful about movement while using NSAIDs (bute, banamine, previcox, etc.) as it masks pain and encourages more movement than these fragile feet are actually able to withstand. Additionally, NSAIDs (and icing) do not work on metabolic laminitis and long term NSAID use interferes with healing. Therefore, we recommend tapering off NSAIDs after the first week or so of use. If after a week's time your equine's comfort level has not increased, then the cause of the laminitis has not been removed and keeping up the NSAIDs isn't the answer - you need to address the underlying cause.


There is lots more information in our files and archived messages and also on our website. It is a lot of information, so take some time to go over it and feel free to ask any questions. If you are feeling overwhelmed, don't worry, you will catch on, and we are always here to help you! Once you have your case history uploaded, we can help you help your equine partner even better.

For members outside North America, there are country specific folders in the files and many international lists in the wiki to help you find local resources.

If you have any technical difficulties, please let us know so we can help you. 


Martha in Vermont
ECIR Group Primary Response
July 2012 
Logo (dec. 7/20/19), Tobit(EC) and Pumpkin, Handy and Silver (EC/IR)

Martha and Logo



Thank you, Sherry.
Thank you for replying and your input. I am hoping I have everything setup correctly now and the link is active. I also added the latest hay test (uploaded into case history) I received today. This is a Teff that I was feeding Cody along with the Timothy. I opted for the "wet" 603 test from Equi-Analytical in the hopes of better accuracy and it came in at ESC 4.8 and Starch .4 as dry matter. We cored from every bale in the batch so at 5.2% I am hoping we are safe. I am feeding him just this Teff from now on and still soaking the hay in hot water for 45min until I know more.

I have not done x-rays. My vet diagnosed him as not laminitic via lack of heat in hooves, no rxn to hoof testers, no rxn when pressing on coronet band, no "laminitic" stance or issue picking up feet, not laying down excessively, and no digital pulses. My farrier yesterday also didn't see anything in his feet that rang the founder bells for him at this time. None of that is very scientific, I know.

I agree with you on the concern over his ACTH level but my vet is really not wanting to discuss Cushing's or the idea of using pergolide at this stage which is frustrating. He is recommending we retest his ACTH in January for a definitive diagnosis. Are there dangers in giving pergolide to a pony that doesn't actually have Cushing's in the hopes of bringing their ACTH down? Getting his ACTH down seems like it should be addressed sooner rather than later in conjunction with the metformin in getting his insulin under control.

My vet also recommended I put him on Enrich by Purina as a ration balancer which I have not done as I did not see it on the "safe list". I have always given him California Trace,  Equerry's Large Animal Probiotic, loose iodized salt, and stabilized flax mixed in a small amount of chaffe (soaked Standlee Timothy cubes) as a carrier but he said that was too complicated and to just give him the soaked hay and 1/2lb of the Enrich daily. Instead of the Enrich I got some LMF Low NSC Complete and am giving him that (8oz) as a carrier (instead of the chaffe) for everything I normally gave him minus the California Trace so I don't end up giving him too much Selenium. I am really hoping that was a not a bad decision.

Vet returns tomorrow to draw blood for a CBC panel to check liver/kidney levels to see if there is a problem there that has led to the high insulin. If there is anything else I should be addressing with him I would appreciate the input. I will try again to broach the pergolide issue.

Thanks a ton. This is all so complicated for me at this stage.


Eileen Towner in Western Washington state 2020  .

Sherry Morse

Hi Eileen,

Thanks for getting your files posted.  For the hay analysis you want to look at the 'as-sampled' numbers not the dry matter but you should still be ok with that level of ESC+starch and not need to soak it.  

Without x-rays you have no idea what's going on internally with Cody's feet and frankly with his insulin that high and the signs that you saw it's very likely he had an episode of what's commonly called sub-clinical laminitis.  The timing is also indicative of it being related to elevated ACTH and again, elevated ACTH will drive up insulin.  What that means is that while getting his diet and trim correct will help getting those triggers under control, without getting the ACTH down you're still not addressing all the possible triggers.  

At this point you could just wait and test him in January again but I would expect if you do so you'll still see an elevated ACTH at that point, even if it's not quite as elevated as it was earlier this month.  

Enrich is NOT suitable for an IR equine - by Purina's estimate it can be up to 15% sugar+starch which would be enough to literally blow the feet off of a sensitive horse.  Standee isn't a bad choice but they do not guarantee their product to be below 10% ESC+starch - you also have the cubes you're using listed as the timothy/alfalfa cubes - if that's the case no more alfalfa as many IR horses can't handle it.  

If you can find Triple Crown Natural Balance Cubes they're actually Ontario Dehy Timothy Balance Cubes which are guaranteed to be below 10% ESC+starch and do not need additional minerals to be balanced (although you would still need to balance to your hay).  Another option for any supplements would be to use just rinsed/soaked/rinsed beet pulp instead as outlined in the emergency diet in your welcome letter.  

Kirsten Rasmussen

Hi Eileen,

It really sounds like you're doing everything right, which just re-emphasizes Sherry's point that the high insulin and pain could be related to the high ACTH.  If you are soaking that 5.2% hay, then the dietary sugar is about as low as you'll ever get it.  Maybe your vet will consider a short trial of pergolide since you've got everything else covered for the EMS aspect and insulin is still alarmingly high.  Pergolide may have some initial side effects we call the 'veil' but once the horse has adjusted to their dose I understand it yo be a very safe medication.

One other thing that us volunteers were discussing recently is that minnies really are hard to manage.  Their insulin can remain high despite careful diet and ACTH control.  It was suggested that they really need a lot more exercise than they normally get, and that they do better at a lower BCS, around 4-4.5 / 9.  Just a couple more factors for you to consider.

Kirsten and Shaku (IR) - 2019
Kitimat, BC, Canada
ECIR Group Moderator
Shaku's Case History  
Shaku's Photo Album