How long does it take to show results with pergolide?

Michelle Riley

Hi Group,

I've been a member since 2009 and I'm located in NW Indiana.  My 19 year old cushings horse has been on Pergolide for a year and a half.  His dose was fine, until last year's seasonal rise.  I increased his dose, but have been chasing the disease since then.  His major symptom is loss of muscling/topline.  Over the past month, I have been gradually increasing his dose.  He was at 2 mg for 2 weeks without a change in his appearance.  We've bumped him up to 3 mg 2 days ago, using APF, which seems to really help him feel better and his appetite is great.  We split his dose am/pm.   My vet did draw for an ACTH test 2 weeks ago.  Of course, she used her lab and his results came back right in the middle of the normal range.  So, in her mind, he is fine.  But, I know what he looks like when he is healthy and he is not healthy.  His eyes are very goopy, too.  So, my question is, how long does it take to notice improvement in his body condition when you've hit upon the correct dose of pergolide?  Should I wait for a couple of weeks on a new dose, watching carefully?


August 2009

NW Indiana

Michelle Riley

No one has answered me.  Is this a dumb question?  I'm trying to get another vet out to do a Cornell test, but in the meantime....  I'm just wondering when the Cornell blood test says the dose is correct, can you actually see the improvement happening in his topline - does it improve rapidly or does it take a couple of months?  Worrying about my boy....


August 2009


Nancy C

Hi Michelle

I could have sworn I answered this.  I'm sorry.  In no way is it a dumb question.

Once you hit the right dose, you should see improvement right away, especially in the top line.  If there are complications from IR being involved, diet not quite right, foot issues, you may not see the improvement you are looking for.

Some members have found that even if the ACTH is in say, dead middle of normal, they need to go even a little lower to see results.

Can you point us to an updated Case History?

Nancy C in NH
ECIR Moderator 2003
Learn the facts about IR, PPID, equine nutrition, exercise and the foot.
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---In EquineCushings@..., <michelle47322@...> wrote :

No one has answered me.  Is this a dumb question?  I'm trying to get another vet out to do a Cornell test, but in the meantime.... 

Michelle Riley

Thank you, Nancy. I thought I had a case history for him 4 years ago, but can't

find it.  Tried to join ECHistory9, but after it gave me 7 different codes and kept saying unable to load content, I went down the page and clicked on the "subscribe" link.  Hopefully, I can get approved that way.  I will update his file and point to it when done.



Aug 2009


>>>So, my question is, how long does it take to notice improvement in his body condition when you've hit upon the correct dose of pergolide? 

Hi Michelle

In Miami's case, his coat was still dull and woody looking and he had watery/goopy eyes too.  In Jan (I'm in Aust so it was summer), my vet and I I decided to begin increasing his dose to aim for improvement in those signs and in readiness of seasonal rise.  Within 4 days or so, he started to shed his coat (he'd been clipped mid Sept and by end Oct had regrown half his winter coat; I wasn't as tuned in as I feel I am now).  It was coming out in sheets!  Within ten days, he'd lost the dull, woody appearance, which had been mostly on the neck for some reason, and had a beautiful soft coat all over with a lustrous shine.  A true summer coat!  I couldn't believe the transformation in such a short time. His eyes stopped watering and were almost dried up completely.

He was re-tested in March for ACTH and I was stunned to have it still come back at 84.7.  I've increased him further and he's now on 2.25mg once per day.  My vet suggested re-testing end May but I'm mindful of the continued expense of this so I may not do it, especially if everything is looking good.  His eyes have now dried up completely and his coat, although longer again now as we're now well into autumn, is lovely and soft and fluffy.

I believe that the group's recommendation is Pergolide as a once per day dose, rather than splitting.  One of the more experienced here would be able to provide you with better feedback regarding that but I just wanted to share our experience in relation to your questions about time frame.  Perhaps your dose still needs to go higher and taken back to once per day rather than as a split dose.

Lisa & Miami (Arab x RP)

Plus Condor & Woody (unchallenged)

Victoria, Australia – 2010






Michelle Riley

Thank you, Lisa.
This is the sort of information I need to hear.  This horse has always been a glistening true black – never bleaching in the summer.  He seemed to go in iron overload over the past 2 years.  I divorced 2 years ago and had to move him and that’s when his coat changed.  Before my divorce, I had the barn water going through an iron filter.  After that, automatic waterers with no iron filter and a lot of iron for 6 months.  Then on to Indiana where there is a lot of iron in the area, but when I tested the Ph of the water, it is very alkaline.
He was on 1 mg pergolide last year and lost his topline when seasonal rise hit.  Whenever I increased his dose, he’d go off his feed.  It was hard to feed him.  He’d take a couple bites and walk away.  I bought everything to tempt him – everything that was safe for him, anyway.  Even bulk stevia from herbalcom.  
My vet friend is from Michigan (I moved from there to Indiana last year), who is doing the prescribing for me via long distance.  I told him I would try to get a vet on board with finding the correct dose.  He allowed me to get a 3 mg capsule so that we could try and hit on a dose that worked.  I thought the group used to recommend splitting the dose am/pm.  Maybe someone could clarify.  He is on 3 mg right now, but eyes are still goopy and no weight gain.  I’m adding APF (1/2 their recommended dose) to his mash and it must be helping tremendously as his appetite is great.  He does, however, seem to be dopey.  Almost like a good wind would knock him over.  Too much pergolide?  He’s been on the 3 mg dose for 10 days.  My husband and I think his dose needs to be higher yet, but he seems so drugged, we’re not sure.  Maybe I’ll bring him back to 1.5 mg/day and start over.
I’m waiting for a response from another vet in the area for the ACTH test.  If she doesn’t respond (she specializes in teeth float and chiropractic, but has lab work available to her), then I will have to go convince my 74 year old vet to humor me.
I’m waiting for my acceptance into ECHistory9 to enter his case history.  It hasn’t come back to me yet.
Thanks for your response.  I’ll take any others that would care to write, too!!!
Michelle & Shadow
NW Indiana
August 2009

Claudia Goodman


After starting my 23 year old mare on 1mg (prascend) in February, I saw little change after 6 weeks and upped the dose to 1.5 for a week, then 2mg. About 3 weeks after being at 2mg, my mare's energy changed so much that we started to fly over the trails again. 
I knew we were at the right dose with her energy returning. And her ACTH came back at 21 pg/mL right when she started flying over the trails (ACTH was at 33.8 at 1mg). However, she still was not shedding out... I decided to give it time (rather than adding other meds or supplements) and she finally is shedding like crazy, about 2 weeks after her energy returned. 

Because the drop in her energy level was the most evident sign of PPID for her, I feel like I can watch her energy level for signs pointing to a needed dose change, as well as checking her ACTH for the seasonal rise in late summer. 

I also want to note that I recently stopped watering my horses from our well, which tests high in Fe and Mn, as well as several other metal ions. May be a contributing positive factor, but finding the right dose seems to be the magic.

Claudia & Silhouette 2014 California


Hi Michelle,
ECHistory8 is where new case histories are currently being posted.  I sent you an invite to join.  I also checked for "Michelle" and "Shadow" in my list of case histories and could not find it.  It may still be in the Internet Archive's copies of the sporthorses case histories.  You can check to see if it is there by clicking here:

If you need any help getting your case history up you can post a message asking for help or just email me at ThePitchforkPrincess (at) gmail (dot) com.  

There also are some documents in the files that you might want to check out offering help and guidelines on how to effectively set up, upload a case history, where to post your photos,  etc.    They can be found here:

- LeeAnne, Newmarket, Ont
ECIR Archivist 03/04
Are you in the Pergolide Dosage Database?    
ECIR Files Table of Contents:  


Hi Michelle,
In case this has not already been brought to your attention, the experience of the group is that splitting the dose may not be as effective as giving a full dose all at one time.  Going from 2 mg all at once to 3 mg but as a split dose (1.5 mg twice a day) might not be more effective than the 2 mg.  In fact, it might be less effective.  Since you posted on April 23, by now you should have seen some improvement.

As far as I know, the only reason to change to a split dose is if you have seen side effects such as loss of appetite or symptoms of "veil" from a full dose, or you want to add extra pergolide when you are already on a very high daily dose to achieve better control.  On this list, 2 or 3 mg of pergolide is not considered a high dose for a horse, or even a pony, and is usually well tolerated (see the pergolide database).  We have a 12 H 450 lb pony on 4.5 mg pergolide who was titrated up in September from 3 mg by adding 0.5 mg pergolide every 3 days with no side effects or veil.  He has stayed at that dose without side effects.

If you want to switch to a full 3 mg dose once a day, you might go to 2 mg plus 1 mg  for 3 days, then increase one dose and decrease the other in increments of either 0.25 mg every 3 days (or 0.5 mg every 3 days if he will tolerate that).  Alternately, go back to the 2 mg once a day, and increase with 0.25mg which is the list protocol (or 0.5mg) every 3 days.

SW Ontario
March 2005

Michelle Riley

Thank you, Eva.  I will put him on a once a day dose.  All last fall whenever I tried to increase his dose, he’d go off his feed.  His appetite hasn’t been the best for a couple of years.  Hard to get minerals and such into him.  He has been eating very well, it seems, since the first dose of APF.  I don’t know if that stuff works that fast or if it was just a coincidence.
There has been some improvement – small amount of weight gain, eyes still have goop, but about half as much.  Since, we’re using APF, hopefully he’ll be ok with the 3 mg once a day.  Maybe, he’ll show more improvement with the whole dose at once.  Thanks for your response.  I’ve been wondering about dosing.
Michelle & Shadow
NW Indiana
August 09


Hi Michelle,

So good to hear that Shadow is making good progress.

When you were increasing the pergolide, were you increasing slowly, by 0.25 mg every 3 days?   This method decreases the chance of side effects like loss of appetite and dopiness.  APF helps with this too, so good you have added that, but will still need to change the pergolide dose slowly.


(Should you decide to try to withdraw the APF at some point, do that very slowly too.  Do not just stop it abruptly.)


If you were increasing pergolide in small amounts every 3 days, and he was still going off feed, Shadow may need to be increased even more slowly, and may need to remain on each small increase a few more days or a week before going up to the next level.   If you notice going off feed again, then go back to the last dose for a bit longer until he has stabilized, then try the increase again.


Thanks for the link to your case history. I noticed a few things that could be adding to Shadow’s problems…..


If you did not know, ACTH results from MSU have been found to be unreliable by a member on this list.   For years, her horse was testing normal at MSU, but began having symptoms of uncontrolled Cushings.  Then she sent identical samples to MSU and Cornell –  ACTH normal from MSU, but high outside the upper range at Cornell!!!  This scenario was also confirmed by Dr Kellon from other sources. 

    The CliniLab used for ACTH by your vet could send out the sample to another lab.  There is no harm in contacting that lab directly yourself and asking if they perform their ACTH tests in house or if they send out the samples to another lab, and which lab would that be.   Cornell is the lab recommended on this list since it has been the most reliable for test results and reliable results are vital to keep the Cushings under control.  There is free shipping to Cornell.  We hope you can convince your vet to use this lab next time. 


An IR horse on pasture, especially “grazed nubs” where the highest sugar is, needs a taped muzzle.


If this hay is not tested for sugar/starch, are you soaking it?


If “black oiler seeds” are black oil sunflower seeds, these are not recommended because they are much higher in the omega 6 fatty acids than the omega 3, and can promote inflammation, so it would be best to eliminate these.  High fat diets are not recommended either.  Now that Shadow is eating better, he may be interested in more hay for those calories, or you could increase the flax by a small amount if needed, but try using your other feeds first.


The recommended NRC daily iodine intake for a 1000 lb horse is 3.2 mg.  Using the full scoop found in the Source will provide 14 g of minimum 660 ppm product containing a MINIMUM of 9.2 mg iodine. This is 2.8 times the NRC recommendation, and likely contains even more.   Using 5 g of Source would contain at least 3.3 mg of iodine, and likely more, since this product is not standardized to provide a defined amount.


We add 1 to 2 ounces (28-56 grams) table salt to the daily ration to meet the minimum sodium needs  for optimum health.  We do not assume that a horse will consume enough on his own to prevent dehydration.  When on a hay diet, it is especially important to make sure they drink enough, and adding salt to the ration will promote this.  As well, if a horse does not drink well, he will also not eat.  So adding the salt to your  mineral mix might help his appetite and low weight as well.

If providing enough kelp (Source) to meet the iodine requirement, do not feed iodized salt.   


When you get in your new hay, make getting a good core-sampled analysis and a “Dr Kellon/ECIR style” mineral balanced diet with appropriate calories a priority.  Shadow really needs it.



SW Ontario

March 2005,   NRC Plus

Michelle Riley

Thank you, Eva
Yes, we increased his dosage in increments.  Just getting him to 1 mg was hard, but I wasn’t using APF at that time.  He’s at 3 mg now and his appetite is very good.
I found out about the inaccuracy of the MSU test from the pharmacist at thriving pets.  He told me exactly what you said.  We began pergolide treatment on clinical signs after the second test.
Shadow is not showing any signs of laminitis at this time.  His weight is improving and one eye has stopped running – the other still has a little trickle.  He is shedding, but rather slowly.  I took him for a ride last night and he was willing and energetic. 
On May 9th, I switched him from am/pm dosing to just pm dosing of pergolide.  I’m hopeful this will show just a bit more improvement.  Last night, I cut his Source down.  He hates salt in his feed, which is why I used Source.   I can try it again now that he’s on APF.
I am very anxious to get my hay tested now that we are settled in Indiana.  My horses never looked as good as when their feed was balanced. 
Thank you for your input.  I will post as changes or questions arise.
Michelle and Shadow
August 2009
NW Indiana