Prasend affect on immune system? Success of chewable flavored pergolide


Is there any truth to a vet's claim that I talked to today that more than 1 mg of Prasend detrimentally affects the immune system? She was very serious about not prescribing more than 1 mg, and as I was pressing her a bit with "facts" of horses being on it at higher doses and for long periods of time, she said yes, some horses can, but that it doesn't track those that fall by the wayside. She claimed that there are other medicines to help with IR, other therapies, including acupuncture (but would not tell me the names of meds or therapies without an extended farm call.) When I told her that he was improving on 2 mg, she said she would have to consult with an internist before she would ever go there. (Would this be an additional charge to me?) She said her goal would be to get the horse off pergolide altogether. Is this possible? She is the second vet that sternly talked to me about how "dangerous" pergolide is above 1 mg.
Is any of this valid? Does the site track in any way the horses that do not do well on higher doses? What should my counter point be when this is brought up?

I talked with another vet who said compounding is only for when horses won't take Prasend. . .or she loses her license.  I told her I have to watch him like a hawk for spitting it out and she said we could try the molasses/apple flavored chewables. Any feed back on these? I worry that as picky as he is, he won't eat it. Is it true that capsules are not available? He eats his vit E just fine, o I thought that would be the best option...but not available? Liquid doesn't seem a good option for him. He fights me on syringing Alcar and usually spits out a good bit on me. The pharmacy said the dustless powder has sugar in it, and not appropriate for an IR this true?
Any guidance you can offer?

Ahhhhhh....I am getting so weary. It doesn't seem like it should be this hard to find a vet and get him on the right dose of pergolide, let alone try to get it compounded! Is there some weird thing in Oregon? My current vet tells me compounding is illegal, too, although he has me buying Prasend through an online company that uses his clinic's name, so maybe he just has no motivation....
Thanks much for your thoughts and help in responding,


Feb 2017, Sherwood, OR

Case History  .

Lorna Cane

Hi Joan,

It's so discouraging to keep bumping into vets who are so uneducated wrt IR and PPID.
Hang in. You are not alone - not that that is of much help.
ECIR always backs up the advice given with science-based data, blood tests,etc. I wish the vets who espouse what yours does would offer some data to back up their (ludicrous) hypotheses.
So your vet should provide data showing that more than 1 mg of Prascend is detrimental to the horse's immune system,for example. It's nonsense.
She says there are other medicines to help with iR? Other than Prascend? Prascend isn't used to treat IR, is the first thing she needs to know.It is used to treat Cushing's. She could educate herself on the difference.
As far as taking a horse who needs pergolide(Prascend) off it, we have members here who have done that because of poor professional advice.The outcome is not pretty.

You are on the right track, Joan. Remember he's your horse, and he's relying on you to search out what's best for him. You've already been doing that,and have noticed an improvement on 2mg of Prascend.That tells you something, even if your vet isn't impressed.
Lots of us have used compounded pergolide for years and years. Some of us have had to go up to 20+mg doses.
I have had 7 PPID/ IR horses over the years. I would have had to euthanize them had I had to purchase Prascend. Back in the day Prascend wasn't around,but our local vets wanted us to use pergolide from a vet pharmacy in the area,which charged an arm and at least one leg. I searched and searched until I found a pharmacy on the other side of the country (Island Pharmacy,in BC ),which compounds pergolide, does periodic testing of its product, and is affordable.
My boys lived well  into their 30's, one of them into his 40's, and were on upwards of 10mg pergolide as they aged. None died from PPID- related issues. One is still with us. He's 45, and on 12mg pergolide, which I suspect his upcoming test results will show needs to be increased.

Keep reading the Files and archived messages.
I know you've been looking for another vet, so hopefully you'll be successful with that search.

I know it's exhausting, but the struggle is worth it.
Hang in. Your instincts are good.


Lorna in Eastern Ontario, Canada
ECIR Moderator 2002




Hi Joan, 

I'm sorry to hear that you are going through this very frustrating experience.  I would encourage you and your vet(s) take a look at the 2015 No Laminitis proceedings, in particular the "PPID and IR Myths and Misconceptions."  You and your vet can download the proceedings for free.  Go here:  

The legality of compounded pergolide has been discussed here many times.  Here are some posts that might help you: 

Liquid pergolide is the least stable form, so not a good long term choice for any horse.  Here's our file on pergolide which may answer many of your questions and give you information to have an educated discussion with your vet(s): 

Pay particular attention to the pergolide 101 file here: 

Hope that helps you some.  Hang in there!

Oh, and BTW, your CH still states that Sonny is on 1mg pf Prascend and as of 3/18/2107 he was "very thin", but your note states that he is "improving on 2mg".  Can you update your CH with all of the latest changes please?  It really helps us to see the whole picture in one place.  Thanks!

Maggie, Chancey and Spiral in VA
March 2011
EC moderator/Primary Response


Hi, Joan - I just want to chime in and agree with what Lorna and Maggie have said.  Sonny is so very clearly PPID (Cushing's) that taking him off pergolide would be exactly the same as removing insulin injections from a Type 1 Diabetic, or preventing a clinically depressed person from having their anti-depressants. The outcome could not possibly be good. Pergolide side-effects in the horse are pretty minimal, and usually restricted to the first week or so (lethargy, lack of appetite, etc). The heart-valve dysfunction that happened to some humans on pergolide has been shown to be dose-dependent, and even horses at the highest doses in our data base don't come close to the mg per kg body weight that some humans were taking.

The side effects of PPID, on the other hand, are very well documented, and can be truly terrible, including persistent infection (due to suppressed immune system); laminitis; and feeling lousy. There is muscle loss, weight loss, and weakness. Some of them show depressed appetites. There have been a small number of horses seen on this list who died from infection after the owner stopped using pergolide because of an inaccurate perception that using drugs was bad, or that pergolide might be "toxic".

BI, that manufactures Prascend, has had a very aggressive marketing scheme aimed at vets, including letters saying that compounded pergolide is illegal, unethical, and much like boiling babies. Their marketing is impressive, I will say. However, compounding pharmacies that have butted heads with the FDA have won. If your vet is concerned, all he or she needs to do is write a script for "pergolide", instead of for "Prascend". You then take it to the pharmacy, or the vet's office faxes it to the pharmacy, and the vet is totally in the clear. If the vet's office were to try to sell compounded pergolide, that would definitely be illegal (for a variety of reasons). However, providing a script is perfectly safe.

Hang in there.

Jaini Clougher (BSc,BVSc)

Merlin (over the bridge) ,Maggie,Gypsy, Ranger

BC 09
ECIR mod/support




Lorna and Maggie....thanks so much for your replies. I was so down yesterday...good to hear a few positive voices of support! Thank you, thank you for being there for us!!
I caught a break today...(Snoopy dance !!!) I got a call from the vet who suggested the flavored chews. She was coming to a neighbor and offered to drop by today and split the travel charge, which I thought was very nice for both of us. I ended up liking her a lot, and she is totally on-board with getting his ACTH under control by raising dosage. She taught me how to feel for pulses (which he did have :-(  and explains why he is so gimpy. His diet is totally under control, so must be driven by ACTH. We set up a protocol of communication...I am to keep track of his symptoms and report this in an email to her every month, and we will increase dosage 1/4 mg per month until his symptoms have improved adequately.She encouraged me to call her if I have any other questions.

After discussing my concerns about how picky Sonny is, we ended up deciding to try the dustless powder instead of the chews, and it also makes it easier to increase dosage. (I totally spaced the sugar question. Hopefully there's not enough to matter to his IR? Fingers crossed.) One of the hesitations I had was her insistence that compounded is nowhere the quality of Prasend, and that she would only go through one pharmacy because she was familiar with their quality.(I posted a frustration earlier that a number of pharmacies in my area charge MORE than Prasend for compounded.) It turned out that it is one that the ECIR website lists, (Wedgewood) so that raised ECIR credibility for her, and made it more affordable for me.  It is interesting that the difficulty I had getting Sonny to take his medicine is actually what made it possible to get the compounded. This trait of his personality literally saved his life!

On another note...yes, I will update the case history soon. Thanks so so much for your patience. I was recording things in a notebook that somehow became lost, so I will have to look some more, or sit down and reconstruct the best I can. Just haven't had the energy/time to do it yet.... Now the vet hunt is over, that helps. My next hunt is for safe timothy hay as people are haying right now.(HAVE to quit buying the Timothy cubes as his main diet! So expensive.) I finally found a chipper that seems promising. I ground up some of his old grass hay, but he won't eat it, even soaked.  He doesn't quid it, just doesn't eat it. I'm thinking it is because the timothy is much yummier. . .

Thanks. Be in touch soon with promised CH!


Feb 2017, Sherwood, OR

Case History  .


Oh. I see your note now too, Jaini. Thanks for weighing in. Don't know what's going on, but so far, no vet I talked to would give me a written prescription when I suggested that (including my most recent.) I asked very nicely how they could not, since Oregon has a law that requires that they do, and I was told that how they get around that is to have a policy that they CALL the prescription in, and would do so for me if I were buying Prasend anywhere. But they would refuse to call in to a compounding pharmacy. Don't know. I am thankful not all vets are like this. Just hard to sort them out and find a good one without spending time, $$$ and/or being emotionally beat up!


Feb 2017, Sherwood, OR

Case History  .