Searching archives and interpreting ACTH results in fall

Saucier Kathy

Hi, I'm not new to the group but have been without an EC/IR horse for 9 years now.  But now my 19 year old is exhibiting some issues so we tested insulin, glucose and ACTH.

Trying to catch up on things since a lot of new information has come out since I was following the group so closely.  Some of the oldies on here remember Magic, my work to get ODTB cubes to TX, testing some feeds, etc.

We are in the middle of our son's wedding planning and a trip of our own to follow and have limited time to search, read and catch up or post this new case history so I'll get to the point of my question and get to the case history in a couple weeks.

I found the Liphook graph of ACTH values through the months of the year by searching on the archives.  I was surprised that isn't on the ECIR website, just info about the seasonal rise, which I knew already.

With that site,, was the more recent 2016 study and graph by Durham.  It is showing by week 37 (our test date was Sept 14) normal range could be in the upper 40's.

I know testing in fall is discouraged but we needed to find out what was going on.  Grayson tested at 58.7 (the lab showed normal range 9-35).  So he is above that upper 40 number on the graph.  I'm just wondering how off of normal this is.  Is he early stages but definitely PPID?  Vet wants us to start on Prascend.  I'm assuming Pergolide is no longer available like from Ian Hudgings? He is prescribing 1 mg/day.  Do we need to start at a lower dose and work up to the 1 mg?  That was the old knowledge that I had from 10 years ago.  If so at what do we start and how quickly do we work up?  Leaving my horse in the care of others is a little unnerving in that I can't see side effects as they begin if I'm out of town, so am also wondering how quickly we need to start this.  Like ASAP or sure wait a couple weeks.


Until I can fill out a case history here is what we are dealing with.

For about 3 weeks now he has had a little swelling in the tip of the sheath and his crest has gotten hard.  He was getting way too much hay as the 2" hole hay net allows way too fast of consumption and we have now rationed down to the 1.5% body weight amount  (he was consuming 25 lbs a day and now we are at 15-17 lbs a day).  Vet body scored him 7.5.

He is off the Purina Equine Sr that he had been on when we moved from the boarding facility, but still on when tested.  His G:I ratio came out to 1.46 coming off the Sr feed (1 lb a day), unlimited hay and grass.  No laminitis at this point.

We went from no grass to rain season and lots of grass so he is off the pasture and stuck in a stall and run for now.  Have ordered a grazing muzzle so he can go out and move around and 1" hole hay nets to slow his hay eating so he doesn't go long periods without.

His current diet in addition to the 15 lbs Timothy hay is 8 ounces twice a day of TC Balancer with 9.2%ESC & 1.8%starch.  He has been on a daily amount of less than a pound of alfalfa cubes which has helped prevent his impaction colics that he used to get. But the easy to soak large pellets from Dumor have molasses added so we are back to long soaking alfalfa cubes or pellets.   I really don't want to remove this bit of soaked alfalfa cubes if possible.  He also gets salt, Vit E and joint supplement which I can get amounts into the case history in a couple weeks.  Just throwing this out there because I know I will be asked.

Oh and his sheath swelling has gone down today - yay!


So sum it up, questions are

1. can we trust the ACTH value to show PPID when done in September?

2. whether we need to work up to the 1 mg Prascend and how much for how many days?

3. can I wait a couple weeks to start it so I can observe him for side effects or get going asap?

4. is Pergolide still available somehow?

5. how quickly will a crest soften once we have worked on the diet?  That was a symptom Magic did not have.  He had the sunken eyes (which went away on treatment), sheath swelling (especially if he got ahold of leaves), long hair coat (never went away).  From what I remember every horse is different and I have to learn what the symptoms are on this horse and what they mean for him as far as IR and C's.


Kathy Saucier

19 yr old TWH gelding Grayson


Restarting 2018, but with group since 2005?


Lavinia Fiscaletti

Hi Kathy,

I sure do remember you and Magic. Welcome back, sorry you find yourself in need again.

A couple of questions for you: what were the results of the insulin/glucose tests? Where was the blood work sent?

Testing during the seasonal rise is fine to check the status of an already confirmed PPID horse. Testing for the first time can be a bit of a grey area. Grayson's results are hinting at early PPID but aren't undeniably positive as older horses in general tend to have ACTH levels that are somewhat higher than young horses show. Whether to start him on pergolide or not is a bit of a judgement call at this time as seasonal rise is peaking now, with ACTH also topping out and starting to drop over the next month for non-PPID horses. If you opt to start him, definitely titrate up the dose. A small dose of pergolide is not likely to hurt even if he isn't PPID, may help, and could be stopped after the rise period in order to retest without the seasonal influence in play. Because he has had no signs of laminitis, you could probably just make sure the diet is really tight and opt not to start the perg now then plan to retest him after the rise or in April for a more definitive answer. I know, clear as mud :(

Compounded pergolide is available with a script but now that the patented, equine version Prascend is on the market, many vets don't want to prescribe the compounded. Here's the list of compounding pharmacies that members have used successfully should you go that route:

He's definitely IR but without a leptin test it's unclear whether this is baseline IR or only being driven by the seasonal rise. Being a TWH makes it more likely he's baseline IR and the seasonal influence has exacerbated that tendency even without PPID. You're already working on getting the weight down. Good on stopping the Senior feed. The TC ESC+starch numbers are only averages - not a guaranteed analysis for every batch. Whether it is a good match for your hay or not is unknown unless you have an anaylsis for the hay. If the alfalfa isn't bothering his feet, no problem to keep using it as long as you are taking it into account in the mineral balancing as it is adding significant calcium to his ration (6-7g per pound). G

Crest should soften fairly quickly, esp if it is a new symptom, once the diet is tight enough and he loses the extra pounds as that is an IR symptom. Make sure the muzzle is sealed - no grass - for turnout. Be careful not to cut his hay allotment back too quickly to lose the weight as that can backfire on you by having his system go into thinking "starvation". Feed him either 2% of his ideal weight or 1.5% of his current weight in soaked hay daily - whichever amount is larger. Adjust downward as he loses weight.


Lavinia and George Too
Nappi, George and Dante Over the Bridge
Jan 05, RI
ECIR Support Team

Saucier Kathy

Thank you so much Lavinia!
Clear as mud?  No, actually very very helpful!
Good news is my vet uses Cornell.  I'm impressed that this young vet is actually up on some things like using Cornell and doing the ACTH test.
Insulin was 88.06 uIU/ml
Glucose was 129 mg/dL

The same day as I wrote, I went back out to check and the crest had softened already. I was thrilled.
Thanks for the advice on the hay.  I did cut back too much and he was starving so I have redone my calculations of 2% ideal weight.  But I have a question about that.  If he gets 1 lb daily of the balancer and 12 ounces of the alfalfa pellets, do you subtract this from the total pounds to get the hay poundage or is this percentage for just the hay?  He has always measured around 1050-1100 lbs (but taping to 1150 2 weeks ago).  If I want to slim him to 1000 and calculate 2% to 20 lbs, I changed the hay amount to 18 lbs to take into consideration these other parts of his diet.  Is this wrong and I should give him 20 lbs hay?  When he gained weight and started the sheath swelling and crest hardening, he was consuming closer to 25+ lbs a day as the bale was in a net with 2 inch holes (plus the grass coming in with the rains).

Looking through the emergency diet and the magnesium oxide, is there any problem using human products that are magnesium oxide since I have it on hand for myself?  They are 250 mg tabs.  I've been putting 2 (500mg) in with the alfalfa pellets for now until I can really get down and do hay testing, etc. and work the real needs.  Is it safe to go more in the interim to get up to the emergency diet amounts?  Lucky for me he has no problem with eating vitamin E capsules and the magnesium tablets.

Grazing muzzle is on order.  First one was too large.  Do I remember right to use duct tape on the center hole, outside and inside?

My responses to email are a bit long in-between with my son's wedding in 3 days and lots of family in town.  But I did print off and study your great help for the last couple days.  Thank you so very much!!
Kathy Saucier