Dumb down what IR testing to do

[BroncoMo]

Situation: 21 year old cushingoid. Relatively managed with compounded pergolide. When I got her 3 or so years ago, her body condition was terrible. Weight on her ribs but her topline looked like a rescue case. 1 mg wasn’t cutting it. Bumped it to 2 and she did a 180; topline was about 95% of what I would expect for a horse of her age, ACTH levels improved but still elevated as of last fall. This summer, she would not shed so we bumped to 3 mg. After a month or so, she began to shed for the first time that I’ve owned her. Admittedly need to retest but it would seem that current protocol is to treat the symptoms; in other words, even if her levels were elevated, we likely wouldn’t increase pergolide since she has shown an improvement in clinical symptoms.

I would love to be able to turn her out to graze some, even if minimally. I live in the western plains where grass is scarce, often stressed, and growing season is short. Drought makes it worse. So sugar content is of a concern. The mare has never been laminitic. She’s an easy keeper but not an air fern by any means. She’s in good weight for her age and health condition, some fat deposits but they have decreased some with the recent increase in pergolide. Maintains on free choice alfalfa and a ration balancer.

What IR testing should I ask my vet for? I mentioned it last fall to a vet at the clinic I use (he’s not a favorite of mine) and he looked at me like I was crazy and gave me some mumbling answer about there not being a test, or they didn’t do it, or something along those lines. I know a test exists. So is it simply an insulin test? Is it possibly something I could pull blood for and take to my university lab to have tested? They have a sheet of services offered. Perhaps I probably just need to ask one of the other vets at my clinic but I would rather be able to just ask for the precise test needed.

Also any EMS testing I should do? Admittedly EMS versus IR confuses me some…

Really I just want to know if it’s safe to let the old girl enjoy some grass.

Edited because good lord the typos…

[Weezer]

It’s just a straight blood test to measure the level of insulin in the blood. I can’t imagine why your clinic doesn’t offer it. I imagine you could get the blood word done at a university lab.

I currently care for a few horses with Cushings and one that is also IR and has foundered severely over the years. With my vet’s support I usually adjust the medication based on symptoms and only test if I can’t seem to find the right balance.

If you can’t get an insulin test on your mare, I would turn her out on the grass for maybe 3 hours a day and watch her carefully. If she starts to have any digital pulse, or her feet start to fall slightly “heel first”, pull her off the grass. This is how I manage my chronic IR mini (but with a muzzle too). I also give her previcox as a preventative all grass season and that has really helped prevent founder. I watch her like a hawk and if she starts to move like she might be sore, I pull her off the grass for a few days. This approach has worked well over the past two years, after several years of painful struggles to find the balance. For my mini, quality of life is top priority and I think life in a dry lot is not great for her.

Good luck!

[BroncoMo]

Thank you for all of this. I use a few different vets for various things, depending on what I need. One of my vets at Colorado State (where I go for repro help) is an endocrine guru and suggested testing for IR. I should have just asked right then and there if she could do it for me. Instead, I asked at my general/sports medicine clinic, to the guy who happened to do the mare’s dental that day. Not sure why he was baffled by it, or seemed like it didn’t matter; kind of a gruff old fart.

I see that CSU offers an insulin concentration test. Does it require any fasting?

Quality of life is high priority for me as well. I know it would just make her sweet little (big) self happy to do some light grazing. She picked up some wood chewing last fall. Not sure if it was pain related (has a trashed stifle that is much happier now with some injections, Pro Stride, and occasional pulse therapy) but I’m sure getting out of the dry lot would be good for her mental health. And I certainly don’t want to turn her friends out to graze and leave her behind.

[Weezer]

When we have done insulin testing on our horses, we have not fasted the horses first. I can’t even imagine how my mini would tear down the barn if I tried to make her fast

[BroncoMo]

Yeah it sounds terrible. This mare gives a look that could kill, and also make you feel super guilty, when she’s mad at you. If I made her fast, I would get the cold shoulder for at least two days

[lenapesadie]

I just asked my vet about testing for IR, EMS etc. I have an old foundered horse that has exactly two symptoms: 1. Founder 2. Chronic scratches. No fat deposits, no cresty neck, coat is slick as silk. He tested negative for PPID, Cushings, in the spring and then had a laminitic attack late summer and x rays revealed founder. My vet stated part of the PPID testing she does measures insulin. Her approach for my horse is to repeat the PPID testing in the next few weeks, then if levels are high to do another test trh? ACTH? Something like that. At any rate for that second test, her protocol is to test with horse allowed hay the night before but no grain of any sort (RB and hay pellets included) the morning of test.

Best of luck with your girl

[ladipus]

Yes …you can pull the blood yourself and take to a veterinary lab …insulin , glucose & acth …they do not need to be fasted as per Dr Kellon from ECIR group …I would join/follow that group and refer to them.

Equine Cushings & Insulin Resistance Group

ECIR-Group-DDTE-Safe-Feeds.pdf

Also …have you considered trying Prascend instead of compounded Pergolide?? ….as for turnout on grass my 2 Cushings gelding both get turned out on grass …one wears a muzzle and the 35yr old does not and both have been doing fine….not all Cushings horses have IR and vise versa

[BroncoMo]

I am a member of the ECIR group but find that info is buried and weird to get to. Plus the focus is largely on laminitis. Not that there isn’t good info to be had, laminitis just isn’t a problem for this mare at the moment. Ie, not every cushingoid is laminitic.

As for prascend versus compound. I asked my vet if we could try out compound since we needed to increase the dosage quite a bit. It saves me quite a bit of money and works well. I know the difference can be a heated topic.

Thank you for these resources. Looks like the remainder of what I need is a metabolic panel. I’ll see if I can get one pulled. At the very least, I have found where I can send in my own insulin test.

[ladipus]

Was a TRH stim test done while testing for Cushings ?? If not then it’s not truly an accurate result

[lenapesadie]

Nope vet said they only proceed to that if 1. Obvious symptoms or 2. Slightly elevated or almost elevated results 3. Owner request. As my horse tested totally within normal ranges while still grazing full time on lush pasture and doesn’t have much in the way of symptoms, it wasn’t deemed necessary. We will repeat testing this season and may proceed with addtl tests if we get an elevated result

[JB]

You can’t just pull blood yourself and take it to a vet lab. Additionally, blood intended for the ACTH test has special handling that has to be done when it’s pulled.

[BroncoMo]

ACTH has been done. Trying to get to the bottom of what other tests to do to ensure she isn’t (or is) IR.

[JB]

@ladipus

Was a TRH stim test done while testing for Cushings ?? If not then it’s not truly an accurate result

You can get accurate enough results for a lot of horses with the ACTH test, depending on when it’s done, and how PPID the horse is. March? Don’t trust a normal reading unless maybe it’s low normal. October? Pretty accurate, as even early PPID horses will usually have an excessive seasonal rise.

TRH is more useful to detect earlier PPID, sooner, but still, also as long as you do it at the right time, which is early Dec through early July