What Prascend dosage is working for your horse and what was the starting ACTH before Prascend brought it down? I know it entirely depends on the horse and can fluctuate throughout the year, but I wonder if 1 Prascend pill is the common dosage until … what point? The ACTH goes over 100 or 200? What about 300-400 or even higher? Any thoughts or experiences?
2019 my horse was diagnosed Cushings with a number of 93, as Cornell interprets. He stayed on 1/2mg (1/2 tablet) successfully until his latest ACTH test results.
As of this morning (11-09-21) his dosage has been upped to 3/4mg (3/4 tablet). His ACTH reading was 63, as Cornell interprets.
I knew he would need an increased dosage, the subtle signs were there. He will be re-tested in the spring but I’m not holding out hope his numbers will be so low that he can go back to 1/2 tablet daily; I don’t think that happens with PPID:(
He is also IR but has been in IR remission since 2015, so his diet is strict and bland:)
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When my old gelding started Prascend, his COTH was 86. Even though 86 is not an outrageously high number, it took a full tablet to control his level. Took him from 1/2 to 3/4 to full tablet over the course of 6 months. He was a 1050 lb OTTB.
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My late previous horse’s first ACTH result was 782; back then only Pergolide was available so we started him on that. Over the next few years it was raised to 6mg. By then Prascend had become available and he was initially controlled on just 1mg. A few years later he was upped to 1.5mg, where he stayed until euthanized for something unrelated.
He was a 14.2 Arab that lived to 34 years old.
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Thank you for this post.
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Our 14.3 stocky 1000# quarter horse had initially a good indicator of how much Prascend he needed, his sheath would start filling up and then we went from 1/2 pill to a whole one for a month or two, then tried to cut back to 1/2.
That worked for five years, then we had to go to 1 Prascend all the time.
IIRC my horse was diagnosed with Cushings at age 18. He was tested every year so we had a good baseline of his ACTH (high normal, but within normal range) and when his levels were above normal range started on 1 pill per day, dosed as 1/2 pill BID.
I test his levels in spring and fall every year. His “new normal” tends to hang out above the “normal” reference range for whatever time period we do the test in- so for example he might be 42 in April when the Cornell upper bound is 35. From a treatment perspective my vet is not concerned with slightly elevated ACTH when his insulin and his symptoms are well controlled.
This controlled his symptoms until last year. At 25 his ACTH went wildly out of control (116 in July, Cornell upper bound 35; 59 insulin, normal upper bound 40.) We doubled his Prascend to 2 pills per day, dosed as 1 pill BID.
He is now 26. So far this has controlled his ACTH and his symptoms- his spring test had him back to about 42 ACTH and within the normal range for insulin, so my vet did not recommend a change in dose. We are trying to walk the line between managing his symptoms and risk factors and managing his side effects to arrive at good quality of life. His minor pergolide-induced depression symptoms have not changed with the increased dose (hangs out in the back of his stall napping a lot, but responsive to stimuli and curious about his environment. This is a nice way of saying that he’s still emotionally prepared to tear the barn down if he’s bored.) The inappetance has been a problem, largely mitigated by APF. His fall re-test is Friday.
ETA the presentation that led me to start annual testing at age 14 or so is that he’s a furry air fern by breeding. I was pretty much waiting for the diagnosis and it was unsurprising at age 18. I was managing him as a Cushings horse prior to his diagnosis, and he did not develop any additional symptoms we can clearly attribute to whacked-out cortisol in the year that he finally tested as “yeah, you should start treating this.” When his ACTH was uncontrolled last year, it was accompanied by a change in hair quality (but not the profusion or the shedding pattern- he grew more guard hairs,) a persistent case of rain rot I couldn’t fix, and slow healing of cuts and scrapes.
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My OTTB was diagnosed with Cushings at 24. His only symption was being slow to shed, and a thicker winter coat, and the only reason we even tested was because he needed his stifle injected and the vet wanted to check his levels before giving a steroid (we ended up doing Prostride). His levels at the time was 17, which is extremely low based on everyone elses posts. The vet started him on 1 pill right way, but bumped him down to 1/2 when he went off his feed. He was down to 6 the following spring, and he was tested again at the end of October, and he was at 7.7.
My 15 yo Arab/WB mare was dx this spring with her ACTH level about 309. We had a lot of trouble getting the Prascend into her, but the 1 mg pill has brought her most recent ACTH to normal- 2.9 after 5 months of treatment
My 19 yr old mare was diagnosed in the late spring. She seems to be doing well on her dosage - coat looks great, has some more muscle, but we haven’t had a follow up test. Vet said they won’t test in the fall. I know that comparing spring and fall numbers may not be ideal, but it seems odd that there is no follow up testing for a year.
