Cushings/IR test questions for the confused

[grayarabs]

I have vet scheduled to come out next week and have asked to test for Cushings.
I requested the ACTH test - but gal on phone said they prefer the Dex Suppression test - which I don't want to do. I would also like to have my horse tested for IR.
I have studied sites onlines including the yahoo site - and the more I read the more confused I get. I need to call the vet's office today or tomorrow and discuss the tests.
I am feeling like I am asking them to do tests they don't normally do. How to simplify the ACTH/IR test? Is there a test with one blood draw for each test? I read time of day horse to be tested (we have afternoon appointment). Horse should not be stressed.
Blood to be handled carefully - ie spun/frozen and sent same day to the lab/s.
When vets make farm calls do they normally have the equipment with them to spin/freeze/centifruge/whatever? I don't know what to do in advance of vet arrival.
I don't want her to arrive and not be able to do the tests for whatever reason.
Do I assume when requesting ACTH/IR test that the vet knows all the ins and outs?
TIA!

[webmistress32]

the Cushings support Yahoo group seems to have all of the definitive information on Cushings.

I know for sure there is extensive documentation on this very topic in their forum.

[craz4crtrs]

Ask for the endrogenous ACTH and insulin/glucose. I would not do dex. If your horse is sore at all it could tip him/her over into full blown laminitis. Absolutely no if there are any current founder issues.

It has been a few years since I did the testing, but the above worked really well for me. Then getting the diet under control, meds if necessary, all will help stabilize your horse.

My gelding did not stop foundering until he got onto the pergolide, then he recovered well. That was 5 years ago, he's 25 and doing good.


Good luck

[Katy Watts]

Do I assume when requesting ACTH/IR test that the vet knows all the ins and outs?

The vets in my area didn't know about these tests. Go here:
http://www.diaglab.vet.cornell.edu/test/test.asp

On the drop downs put Endocrinology and Equine.

You want the ACTH/insulin. Click on that, you get how to handle, what kind of tube, and there's another link for interpretation.

It is a baseline ACTH, with no stimulation required. One blood draw. Must be spun down within 4 hours, so they must head back to the clinic soon, or you can offer to take it back. I handled all the overnight shipping myself, insulated box with cold pack, to make sure it got done right. Saves me a bunch of money,too.
Katy

[grayarabs]

Tks - will go to those links and see if I can understand.
Wonder - will it mention horse needing to be fed/not fed a certain amount of time before testing?

[grayarabs]

Found the Cornell site and info - Tks!. I don't know what lab my vet uses.
I note on Cornell site:
ACTHINS - test days MWTh
ACTH Endo - test days M-F
Insulin Baseline - test days MWTh

Appointment is for Tuesday (day she can bring x-ray equipment).

Will call vet's office this afternoon and see what I can find out.

[Katy Watts]

Wonder - will it mention horse needing to be fed/not fed a certain amount of time before testing?

This should be helpful.

http://www.thehorse.com/ViewArticle.aspx?ID=12588

[BornToRide]

And good luck getting the or another vet to cooperate. That seems to be the most frustrating part in many cases :(

[Watermark Farm]

Here is some very helpful info about testing. I do the ACTH with my pony as well, not the dex supression test.

http://www.equinemedsurg.com/ir6.html
Equine Insulin Resistance: Testing

And once you get your IR panel results back, this is a helpful tool for converting ratio:

http://www.freil.com/%7Emlf/IR/ir.html
IR Calculator

[grayarabs]

Pulled blood for ACTH/IR on Tuesday - sent to Cornell. I don't know if overnight or 2-day.
How long usually to get results back? Ugh - nervous here.

[Horsedoctor]

Cornell usually has Cushing's Panel type test results faxed back in 7-10 working days, but I have been pleasantly surprised a few times and gotten a 2 or 3 day turnaround. Most of the time if I am concerned about IR/Cushings, etc I will run what we call a Cushing's Panel, which includes for us the ACTH, insulin, glucose (insulin and glucose necessary to check ratio for IR), T4 (which is usually low because of a related metabolic problem and is not often a primary problem, hence fix the cause and not the lab value), and cortisol. Horses being tested for glucose/insulin should not have had a grain meal in the 12 hours or so before the test, and should not have been stressed beforehand, so no exercise or other shots, etc before the blood draw. A lot of people worry about the Dex Supression test, although I was at continuing education talk a few weeks ago and the docs at Penn don't have a problem with it since the research has shown that there is very little risk of laminitis in administering 20 mg of dex one time. All the same I would not do this test preferentially in a horse that has current or chronic laminitis. The dex test does technically require visits on two consecutive days, but some vets are having their clients administer the dex and then just doing the "second" blood draw the next day, because the sample pre-dex is usually normal. Another note, the tests for Cushing's are not really reliable in the Fall due to normal seasonal increases in ACTH.

Vets don't usually carry centrifuges in their trucks to farmcalls; I use blood tubes that I keep in my fridge so that they are cold when I put the blood in them, and then put the filled tubes back in my fridge until I can get back to the clinic and get them spun down. Some tests can be done in-house depending on your vet clinic, but the ACTH and insulin usually need to be sent out.

[grayarabs]

Values within normal range. Cornell Lab. ACTH/IR test. One pull - no stimulation.
Blood pulled 3 pm. Horse had breakfast of alfalfa pellets/cubes approx 6 am - and no other food/lunch.
ACTH 23 (9-35)
IR 9.43 (10-40)

I will watch the shedding. He is shedding now everywhere - less so on belly - and much less so on the leg hair/feathers. These results give me some relief - assuming not false negatives. That he does not slick out in the summer still concerns me, but he does not re-grow a long coat once he is finished shedding. Thanks for all your help in figuring all this out.