She’s proposing a TRH test, where a medication of some type is injected, then blood taken an hour afterward.
I’m equally happy with an ACTH, where I’d pull blood before a meal and bring it to them for processing. But they don’t make money off a farm call if I pull my own blood.
I sure hope this TRH test is more accurate in this ‘less-than-prime’ time of year to test.
Here’s the info from Cornell about each test. I don’t know if the TRH is more or less accurate. Maybe others can chime in. If you pulled blood for ACTH you would need to do it in a specific way for shipping, so not sure if you have that ability or not. But I wouldn’t choose one method over the other based on the vet’s ability to make a profit. I would hope that if they are recommending TRH it’s because it is the more appropriate/accurate test. Repeat business is what makes a vet clinic profitable.
The TRH test is still an ACTH test. First you pull a baseline ACTH, then you inject the TRH and wait 10 minutes, then pull another blood sample to test for post-stim ACTH levels. It is considered more accurate than pulling just a baseline ACTH for diagnosis. The downside is the TRH stim can only be done December through June.
The current thinking is that this (fall) is the preferred time to test for PPID.
I didn’t consider Cushings/PPID. My vet threw it out there as a could maybe possibly be the cause of my horse’s inability to develop muscle over his topline despite good nutrition and proper dressage work. A week or two later they offered me one of the tests that the drug company offered to pay for (I just had to pay for the vet visit to draw the blood, and since she was coming anyway…) and I accepted.
My vet clinic had an information night about PPID and Insulin Resistance a couple of years ago and they had a vet from Ingelheim Boerhinger (sp? The company that makes Prascend) come and talk about PPID. It was really worth going to.
Edit to add: my horse was 16 and we tested in late October or early November.
Vet has had a change of heart after my proposal to have an associate of hers from the same practice perform the TRH test. She had me pick up purple tops and a few needles for a fasting blood draw. Keep it on ice, bring directly to the clinic then they’ll spin down the serum, freeze it, and send it off to Cornel.
Thank you to everyone who’s contributed. I found it comforting to know others weren’t waiting until their horse foundered to test for Cushing’s.
Multiple anaplasmosis infections
dull dry coat
loss of topline
Age 14 at diagnosis
Keep us posted please!!
I’ve pulled blood, it’s at the clinic. They said I should have results tomorrow?? I don’t believe it, but will circle back when I hear. Thanks again.
Two years ago my, then 21 yr old, Fjord went through a summer of excessive sweating and incessant itching. Vet blamed it on the crazy hot, abnormal summer we were having. Yes the weather was abnormal, but I also had the gut feeling there was more going on.
This Fjord has always had a rather thick, coarse coat; starts putting in his winter (yak) coat quite early. Does shed out normally, but holds on to some of his coat until late in the spring. I felt his coat was had subtle changes: looked slightly curly in small areas or little ribbons of longer hair on his flank. (He always had a tendency to curl when wet. Practically looked like he had a perm after getting a bath.) He also had fat pads on the shoulders behind the withers (but always has to a certain extent; somewhat of a breed propensity) and a little bit on the rump. What really changed though was that his neck got quite cresty during the hottest part of the summer when the pasture was dried out and stressed (high in fructans???)
When the sweating and itching was still present in the cooler fall. I pushed the vet to test, but really couldn’t convince her to do so until he was still sweating intermittently in January (when temps were often in the teens). ACTH came back very normal (and have continued to so on each retest). Insulin however, was slightly elevated. Vet says we caught the IR very early. Made some minor diet changes and he was put on Heiro. The insulin level did drop back to normal range and the fat pads receded.
However, he still had occasional odd patches of sweat. Eventually we also tested for thyroid level and that came back borderline low. He is now on a low dose of Thyro-L. That winter he also bowed a tendon. Vet and I discussed that propensity in Cushings horses. First time in the 15+ years we’ve owned him that he has ever taken a lame step. Hard to say if it was Cushings/IR related or just coincidence, as it happened on one of those crazy days when the snow is thawing and slimy and he did play around in the pasture. Knock wood, my farrier always marvels at his feet, says they are textboot and wishes all his clients had them. So no hoof issue to this point. Fortunately the tendon rehabbed fantastically and he is back in full work. At 23, this guys is still energetic and loves to go for rides. (Ya, a unicorn. I’m no spring chicken, but he still has more that enough energy for me.)
Both the vet and I are convinced he is pre-Cushings based on outward appearance, but the tests keep saying “no.” Vet does not think he is ready for Prascend, but has given me the good ahead to add chasteberry to his diet as a bit of pituitary support. She claims to have seen quite good results with it. Hard to say, he seems to be holding his own very well. I will continue to test for Cushing, insulin, and thyroid level regularly.
My other Fjord, who is now 12, is an even easier keeper, has had one mild lamanitc episode, and occasional sheath swelling. The majority of the sheath swelling was during that droughty, hot summer. Hmmm? Did make me very suspicious. The laminitis followed a bad bout of sweet itch that resulted in cellulitis, so not sure it was metabolic per se. There was definitely something amiss with his immune system though. He had only come to me months earlier, needing a change in venue with hopes of easing the sweet itch, so there was still a big learning curve.
I’m watching him like a hawk. Managing him as if he were IR/future Cushings. ACTH and insulin are normal, but he did turn up slightly low thyroid this spring. He is also on Heiro (as a precaution after the laminitis) and a bit higher dose of Thyroid-L than my other horse above. To see him today, he looks great. You wouldn’t know he has sweet itch and he acts like he feels a whole lot better.
This whole metabolic syndrome journey sure has been a learning experience. Never a dull moment and never let my guard down any more either. Hope you get some results soon that can get you on a manageable path with your horse.
ETA: no vision changes, but did notice occasional unexplained spookiness in the younger boy. He may have just been testing as it was really the first time in a while that he was back in regular work. He is quite a lover, but would be perfectly happy being a full-time pampered, pasture ornament.
Well heck, the second ACTH test on my mare was a few points above normal (38, normal is 9-35, and by now the seasonal rise has started.) She was at 42 in August. The vet said we could try Thyro-L for a month since she’s still fat, and see how that goes. Obviously she wouldn’t be on it forever.
This mare is a mystery. We have had multiple rounds of “Her symptoms are classic for common condition or injury X, but on further testing it’s condition/injury Y. We think. Maybe.” And Y is almost always more of a zebra than a horse.
There’s nothing weird about her pedigree, where she was born (except it was in the field in a small herd of mares, rather than in a stall as intended), how she was raised, etc.
ACHT results in. This from my vet:
“ACTH level is 67.8 (normal 9-35 BUT this time of year negative would be <50, equivocal is 50-100, & positive is >100). I am still waiting on his insulin level.” She suggested doing the TRH Stem test December 1.
And his scratches persist.
What does CoTH suggest right now? He’s eating TC Senior, about 2 quarts a day (a/m & p/m). About 5 flakes of first cut grass hay a day. Gets MSM once a day, is on Probios twice daily until it runs out (small jar) and Thia-Cal from Finish Line.
I’m very tempted to get him off TC Sr and put him on dampened Timothy pellets instead. Just something for the supplements to go down .Vet is against this because she’s saying he’ll be missing vitamins & minerals from the processed grain. I think processed grain was something we did to horses and they can live perfectly well on hay.
No, Ihaven’t had mine tested and think it’s kind of pointless given my hay dealer pulls from different farms locally and from NYS when the picking’s slim…
Agree with above; not sure why taking the horse off TC Senior would help, unless you think too many calories? Has he been on the TC Senior for a while, or is it relatively new? (If new, I can understand that hyperreactivity or itchiness might be an allergy?)
You could consider a ration balancer if you think the fat/dimpling is just too many calories.
Has the vet ever evaluated his vision?
I’m having a bit of a time of it with respect to my vet. She saw him last week for a stubborn case of scratches. I mentioned his dimpling fat appearance (no lumps), recent lethargy, the major increase in urination. Then I started thinking about thought perhaps his intermittent hyper-reactivity to odd stimuli (neurologic/ vision issue) and his occasional super itchiness might be all part of it as well. I asked for the test and she cannot return until ‘some time’ after this week.
Here is more why pergolide in Prascend is better than compounded pergolide:
https://thehorse.com/121115/fda-no-longer-supports-compounded-pergolide-production/
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