The seasonal rise in POMC hormones, the hormones affected by PPID (Cushing's disease) tends to start around late July/early August and last until late October or into November - this affects all horses, but particularly horses with PPID, and the seasonal rise can be a good time to diagnose horses in the early stages of PPID.

In the first of a series of articles that we'll be running on PPID over the next few weeks, here's a short video in which Dr Hal Schott describes some of the early signs of PPID. These include:
- change in behaviour/attitude/performance - the horse may become more lethargic or dull, less enthusiastic about work;
- muscle loss along top line or rump, you may notice the saddle doesn't fit quite so well;
- you may notice long guard hairs on the back of the legs, under the jaw or along the jugular groove. The long shaggy coat associated with PPID is usually late to develop and indicates advanced PPID;
- the horse may drink and urinate more - horses can become diabetic in the early stages;
- you may notice that the horse is sore footed, or it may develop obvious laminitis - laminitis could be due to PPID or EMS, but any laminitis, and particularly first time laminitis between August and October, could be a symptom of PPID.

More information about the early and advanced symptoms of PPID here.

Besides, surely tendons don't contract - wouldn't it be the muscle, if anything, that was affected - and wouldn't artificially raising the heel actually be likely to cause the muscle fibres to shorten - the very last thing we want - as recent research found in women who wear high heels a lot (High heels "shrink calf muscle fibres").

Dr Debra Taylor and Pete and Ivy Ramey address the role of the DDFT in their Hoof Rehabilitation Protocol article: "our therapy of laminitic horses is based on the concept that tension of the deep digital flexor tendon cannot result in stress to the laminae if the toe wall is not allowed to bear weight at impact, stance or during breakover. While tension of the deep digital flexor does exert a rotational force on P3, this force cannot oppose the laminae if the hoof wall remains out of contact with the ground." 

The ECIR group has this to say about raising the heel (www.ecirhorse.org - ddt-trim):
"There is really no proof anywhere that raising the heel does anything to prevent rotation. The theory of DDFT pull also fails to explain why horses with the most extensive damage sink or how sinkers can have a perfectly aligned bone column with no rotation at all. In fact, some sinkers are more ground parallel than before the laminitis. Raising the heel has negative effects long term by increasing the pressure on the tip of the coffin bone and accelerating bone loss." 

We now know thanks to research by Melody de Laat  (Insulin-Induced Laminitis - An investigation of the disease mechanism in horses 2011) and others that during endocrine laminitis (~90% of all laminitis cases), the laminar cells stretch, and it is likely that this weakening of the connection between the hoof wall and the coffin/pedal bone leads to laminar failure and rotation and/or sinking, exacerbated by the the horse's weight and perhaps poor foot balance. 

We have recently heard of a horse with laminitis, no rotation seen on initial x-rays, heel wedges fitted, then further x-rays revealed rotation - hopefully a correct realigning trim and barefoot rehab will restore this horse to full health - and hopefully this article will prevent this happening to other horses.

See more under DDFT.