recent tender footed - latest insulin up - please advise on medications


Jenny Heishman
 

Hello all,

My gelding, Rico, 11yo Paso Fino/Rocky Mountain, lives on a dry track since December 2021.  I was hoping that this grass-free environment would bring his insulin values down to normal, but unfortunately, that's not what we are experiencing.

He eats weighed and soaked hay 1 hour cold water (hay test in file....tested both soaked and unsoaked sample)
Balanced minerals served in R/S/R beet pulp
Jioagulan 2 teaspns/day
He's wearing easy care glue on shoes - four week cycle then trim and re-glue.  This last cycle, when I removed the glue ons, I noticed that he was tender footed (had not seen this in previous removals of shoes)  I then noticed some other "tender footed" behaviors, called the vet to run bloodwork and his insulin came back higher than our last test in the end of March.  Please see case history for bloodwork history - four tests in the past two years....none of them with normal insulin.

Current bloodwork on 8/4/22:
     ACTH - 34.8 pg/mL (Normal <20 in Aug)
     Insulin - 56.03 uIU/mL
     Glucose - 98 mg/dL

Previous Bloodwork 3/23/22:
     ACTH - 15.2 pg/mL (Normal <15 in March)
     Insulin - 48.62 uIU/mL
     Glucose - 110 mg/dL

My vet here is suggesting medication, either Metformin or steglatro.  I have asked here before about putting him on Metformin and it was recommended to save it for an emergency, like an active laminitis episode.  What do you all think now?  It's really worrisome to see/feel the slight changes in him with his tender hooves.  Places on the trail that he usually trots off, he is now walking on the ivy plants on the sides.  He has been under the most exercise ever....especially leading up to this....and moving/feeling great until late July.

Vet also says, " PPID is still lower on the list given his age, but his ACTH has never technically been normal with the most recent updated reference ranges and insulin dysregulation/laminitis is sometimes the only clinical sign, especially if early onset. Next blood-work I'd recommend a TRH Stim test."  
Would you agree?

Thank you for sharing any suggestions/thoughts you may have.



--
Jenny Heishman and Rico  
Bainbridge Island, WA   June 2018
https://ecir.groups.io/g/CaseHistory/files/Jenny%20and%20Rico
https://ecir.groups.io/g/CaseHistory/album?id=60437


Sherry Morse
 

Hi Jenny,

His insulin results are high, but not high enough that he should be experiencing laminitis right now.  I do agree with running the TRH stim test next spring but wouldn't be surprised if it came back normal as he's in line with what we expect at this time of year.  https://ecir.groups.io/g/main/files/Blood%20Testing%20for%20IR%20and%20PPID/Blood%20Testing%20for%20Cushings%20-%20PPID/Seasonal%20Influences%20on%20ACTH/Liphook%20-%20Seasonal-Changes-in-ACTH-Secretion2.pdf has a weekly list - we're in week 34 now so you can see he's not out of the adjusted range at all.

Is he tender while wearing the shoes or was he barefoot and tender and then you put shoes back on him?  I'm not real clear on that.  If he's barefoot and tender have you tried putting boots on him to see how he is with them?

Before going to Metformin (which is the first medication choice) you may want to confirm he absolutely can't be getting any grass under the fence of the track and also share pics of the current trim to see if there's something there that might be leading to the tenderness.  




Jenny Heishman
 

Hi Sherry,

Thanks so much for your quick reply. 
I understand that laminitis occurs around insulin levels of 80.  I thought that there could be changes in the laminae at 50? 
The reason why I am writing in for advice, is that my horse is showing hoof sensitivity and higher insulin results.  The hoof sensitivity has just come on.  He has been in glue ons since last October.  I often have the shoes off for a day before getting the next set glued on and he has never shown this tenderness.  In addition to witnessing that....he is showing other behaviors that he did back before living on the track and before the glue on shoes.  Such as seeking softer ground when riding out.  Choosing to walk rather than trot.  This is with his glue on shoes back on.  I would never take him out without anything on his hooves - that's been the case for the past three years.  He also has a pair of easy boot gloves with the thin pads.  I trim myself under the guidance of Jodie Jenson, who is a long time ECIR member, and a very good trimmer.  She is coming on Wednesday, so I can get photos and post them....but I really don't think it's a mechanical hoof issue.

My vet said that the normal ACTH for August is below 20.  So that is why his value of 34.8 look high to me.  Thank you for the link to the weekly ACTH levels - that's super helpful and I will forward to my vet.

Thank you for letting me know that Metformin is the first medication of choice.
There is a string of hot wire on our track that is quite low.  I clip grasses regularly to keep them low and unavailable to him.  It is only a 100 foot long track with a 30' by 40' sand loafing area, so I do have my eye on the whole area.  I would say that from time to time, he is able to get a piece of grass.  But, I think it's unfair that this would be cited as the cause.  Honestly, his bloodwork results don't back that up either.  There was no dramatic lowering in his insulin numbers when he went from a taped muzzle in a pasture - where he was always able to partially rub some of the tape away and get grass....much, much more grass than he is able to very minimally get to now.  The track living started December 2021.  You can see his insulin numbers before that in the case history.  I think he is a puzzling case and I'm certainly scratching my head (and throwing my best at it)


--
Jenny Heishman and Rico  
Bainbridge Island, WA   June 2018
https://ecir.groups.io/g/CaseHistory/files/Jenny%20and%20Rico
https://ecir.groups.io/g/CaseHistory/album?id=60437


Sherry Morse
 

Hi Jenny,

With that additional information I would say you could trial the Metformin (planning on redoing bloodwork 7 - 10 days after starting) and see if it helps with the insulin number as well as the tenderness.  If you see an improvement you have your answer as to how sensitive he is to changes in insulin.




Lavinia Fiscaletti
 

Hi Jenny,

Overt laminitis will generally be seen if insulin rises to 80uIu/ml or higher. However, there is sub-clinical damage being done to the connections anytime the insulin is even slightly elevated. A actually normal insulin is in the low teens or lower. So yes, insulin at 50 is causing some damage to the lamellar connections. Because he already had/has mechanical issues, that insulin level is continuing to make them worse. Even if he isn't PPID, just the normal rise in ACTH during this time of year will make insulin in an already EMS/IR horse rise further, which could be at least part of the problem.

Based on the last rads in his album (8/2021), Rico's breakover was still too far forward on all 4 feet. His heels were underrun, coffin bones were ground parallel, soles thin. If the wires on the rads were properly placed, there was some degree of sinking present in all four as well. Arthritic changes had progressed from the rads done a year previous to that. All of these factors would have contributed to making him sore at that time. As there are no current photos of his trim, can't make any comments as to whether things have improved since then or not.

--
Lavinia, George Too, Calvin (PPID) and Dinky (PPID/IR)
Nappi, George and Dante Over the Bridge
Jan 05, RI
Moderator ECIR


Kirsten Rasmussen
 

Hi Jenny,

There is no real difference in the 2 insulin results.  Both are indicative of sub-clinical laminitis, which appears chronic/ongoing.  I know you do a lot to keep Rico moving to keep his insulin down, but he is going to have tender hooves with those numbers.  Many people compensate for this by using boots with or without pads to get their horse comfortable and ride/exercise anyways because they can't get insulin any lower without meds.  The mechanical issues Lavinia mentioned will complicate the picture and also add pain unrelated to the insulin levels.  As he is not in the danger zone for acute laminitis, I personally would not jump to insulin-lowering meds just yet, especially not Stelgatro (please do a search of messages on Stelgatro, Invokana, and "flozin" to learn about how much more complicated management of diet and exercise becomes on these new drugs).

My advice is to make an appointment for a blood pull as close to the end of Sept as possible to see if his ACTH (and insulin) is unusually elevated then.  If you look at the weekly cutoff values, last year's ACTH of 64 on Oct 10 (week 40/41) was elevated, esp for a young horse.  An elderly horse might have an ACTH as high as 80 during peak rise before we consider it to be abnormal, but at 11 I think he should be within the published range.  Based on my experience with my much older Paso Fino, I thought he had really severe difficult to control EMS but once early PPID was diagnosed and he got on pergolide, I was able to relax a bit on his diet.  I think the PPID was affecting him 2-3 years before we got the diagnosis and started treating it.  His ACTH was normal outside the seasonal rise, but in 2020 came back at 102 in early Oct, which was his first test during the rise.

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


Jenny Heishman
 

Hi all,

thanks for your replies, Sherry, Lavinia, and Kirsten.  So appreciated.

What about a trial on a low dose of pergolide?  Then retesting bloodwork and observing his cresty neck and tailhead fat blob.  (he does not have a swollen sheath)
Does anyone approach diagnosing early onset PPID this way....rather than waiting for an ACTH value that confirms PPID - either by regular bloodwork or stim test?

Just scratching my head about what could be driving his insulin up.  Both of his highest test numbers have been in the fall or approaching the fall.

I've been a member for three or four years and I read the digest almost daily.  I'm in awe of all the horses you volunteers help, all the dedicated owners, and also just devastated by the details on the active laminitis and/or founder cases.  My top goal is to keep Rico from having one single episode of acute laminitis.  Please help me figure out how to best get his insulin number down, I would be oh so grateful.

I have body images up:
body image
cresty neck rightside
cresty neck leftside
tailhead fat

Attention Lavinia :  Hoof images from yesterday are uploaded.  We are seeing progress.  His caudal hoof on all 4 is developing.  Heel bulbs looking much more "plump" and healthy.  Fronts have some retained dead sole around tip of frog, but we only pulled the pieces that were flaking off.....I'm sure he will release the rest in the coming month or so.  I have him in easy boots with 12mm soft pads front and 6mm soft hinds.  Rode out today and he seemed a little more comfortable than he was in his (4th cycle) glue ons.  I will keep him in the boots 24/7, with daily airing out, powdering, for a couple weeks before considering applying his new set of glue ons.
 



--
Jenny Heishman and Rico  
Bainbridge Island, WA   June 2018
https://ecir.groups.io/g/CaseHistory/files/Jenny%20and%20Rico
https://ecir.groups.io/g/CaseHistory/album?id=60437


 

Hi Jenny,
To answer your question, yes there are people who give pergolide to see if it lowers insulin, especially in fall.  I did that myself with a pony on the vet’s recommendation, because the pony was obviously PPID but the testing did not particularly support that.  That pony was considerably older than Rico, though.  I don’t see any harm in trying that as long as you have exhausted all the other possibilities, which you don’t want to ignore just because the pergolide seems easy.  Of course, you will need your vet’s concurrence for a prescription.   

--

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
 


Kirsten Rasmussen
 

A trial on 1 mg pergolide is a possibility, but it's a bit late to start now.  Doesn't mean you can't do it anyways, but you might not see the full effect of the medication.

His insulin isn't really significantly higher than it was in March.  I suspect it would be safe to not do a pergolide trial this year and try instead to get bloodwork done in late Sept that will hopefully confirm early PPID.  You could give Metformin for a couple months if you are worried.  But it's your decision to make.  Your vet might have some input, too, as they seem to be very pro-active (which is awesome!).

The tail pad and crest are much bigger than I would have expected to see.  He also has some extra fat above his eyes.  What do you estimate BCS to be right now?  It looks like he could lose some weight, which would help reduce the fat pads a bit, but I can't be sure from the photos.  Can you see his ribs?

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


Jenny Heishman
 

Hi Kirsten,

The vet gave him a body score of 4.5 last March, and called him a "little thin"
I would say he is a 5 now.  You can't see his ribs if he is just standing square, but when he does most movements - trotting, bending, etc -  they are easily visible. 

His crest is a little less "full" and hard than I have seen it in the past, but yes, the size/shape of it has been like that for three years.  And his tailpad has also been very prominent and very consistently visible.

I'm remembering that his half brother, same Dam (Paso Fino) was lost to founder.  I'm not sure if it was IR or PPID.....but perhaps it would make sense that it was IR and it runs through the bloodline.

Questions about Metformin.  I'm feeling a bit nervous to use it, because folks have recommended saving it for an emergency.  So, the fear of using it now and then not having it available in my toolbox later, if a crisis were to hit, gosh that would be terrible.  BUT, I also don't want him experiencing hoof pain on the daily or to have him unexpectedly get worse - higher insulin - and have a bout of laminitis right under my nose.  My vet is "highly recommending" to start him on Metformin.  She hasn't given me any details as to what that would look like.  I will reach out to her today to get clear on her plan.

Sherry already recommending that if I do a trial of Metformin, to retest bloodwork in 7-10 days.  If that bloodwork comes back with normal insulin, when would I test him again?  Of course, I would be watching his other signs - like his crest and hoof sensitivity. 

What about the idea of using it seasonally?  If the seasonal rise is increasing his insulin (just due to that natural effect) then perhaps I should put him on Metformin in late summer through the rise?  For horses that stop responding to Metformin, can they go off of it, have it clear their body (for however long that takes) and then start up again - will the body respond again? 
I was talking to one of my friends who is in the human pharma world, and she was asking me about Metformin in horses - what was the PKPD?  The residency time?  Questions that I barely understand....but think she is trying to get to the concept of cycling the drug on and off, so that it continues to perform.  I had told her that this ECIR group is seeing that the drug stops working over time.  (I am not looking for a quick fix through pharmaceuticals!  I try to minimize them in my life and also the life of my animals....I am only coming to explore this because I have tried everything else to my best ability and I really don't want my boyo, sweet Rico, to suffer laminitis or worse)

Thanks so much for your time and knowledge,
Jenny and Rico


--
Jenny Heishman and Rico  
Bainbridge Island, WA   June 2018
https://ecir.groups.io/g/CaseHistory/files/Jenny%20and%20Rico
https://ecir.groups.io/g/CaseHistory/album?id=60437


Sherry Morse
 

Hi Jenny,

Metformin is meant to be used when insulin doesn't come down by changes to diet and increased exercise (when possible).  As you've indicated Rico is still sore in addition to addressing his trim that's a good sign that using Metformin may help him avoid a full blown laminitic episode.  

It may stop working over time but that doesn't mean that if you stop it at that point that it will not work again in the future if needed.  I'm not sure we've had anybody report back on that yet at this point.  Starting him on Metformin would need to be 30mg/kg twice daily for it to be effective and then you would keep him on that at the very least through the seasonal rise or until you saw it was no longer working. 

Once on Metformin you retest 7 - 10 days after starting to see if it's working at all.  If it has brought his insulin down to a better place you don't need to retest unless you see signs it's no longer working or you want to do a check on his status.  

If you decide you only want to use it only during the rise you'd want to retest prior to stopping and then check again in 7 - 10 days to see if his insulin is staying down or if it's creeping up again.  If it's going up again you know it's not just a rise in ACTH having an effect.  If it stays down then you know that for next year you probably want to put him on pergolide prior to the rise and see if that alone keeps his insulin in a better place.  







Kirsten Rasmussen
 

Sherry has explained the justification for using Metformin now.  There's some more info on it here, including an overview on how to give it:
https://ecir.groups.io/g/main/files/4%20Insulin%20Resistance/Metformin
You could limit it to times of the year where he becomes more foot sore if you like.

The research studies, and anecdotally some of our members, have reported that it loses effectiveness with time in some horses.  Others remain on it for years because it may help reduce neuropathic pain, too.

If a crisis hits later, you still have the Invokana/Stelgatro option, and it is VERY effective.

We think a BCS of 4.5 is perfect for EMS horses.  A little bit on the thinner side.

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