Chronic Laminitis! Help! (May or May not be Cushing's?)
17yr old Thoroughbred gelding had two laminitic episodes last year: May (after transitioning to a new barn and having his shoes pulled) and late August (out of the blue).
This year, showed up with laminitis in his hind feet. He had other symptoms and a positive Lyme test (titer and western blot) so we treated him with doxycycline. Farrier came out and checked the feet for me, cleaned up what he could. Horse began to look sounder and sounder, personality improvement, laminitis in hind feet did not get worse and he was standing normally. But because hind foot laminitis is rare in horses without Cushing's, vet prescribed pergolide as a precaution and we planned to test cortisol levels in January.
1 week after starting pergolide, the horse is turned out with the whole herd back onto grass. This was not done with my permission, I have no idea he was out of the flat/nograss field until I went out to catch him and realized he was in the wrong field. Less than a full day on grass and he was very foot sore behind, did not want to weight bear on the foot that had the most damage (RH).
Vet wants him in a muzzle or preferably, off the grass.
While I am happy to do that now to manage the laminitis, I am not entirely convinced this is Cushing's and I am worried that we are missing something:
He does not have an abnormal coat at all. His summer coat is sleek and shiny and he's grown his normal amount of fuzz for winter and he doesn't grow a great winter coat.
He does not urinate excessively, or drink an excessive amount of water.
He does not sweat excessively--in fact, he has never been a big sweater.
He does not have any abnormal fat deposits.
What else can cause chronic laminitis? Can a horse have Cushing's Syndrome without showing ANY other symptom other than 3 episodes of laminitis (two at the onset of fall)?
I don't ask that this horse be anything but happy in a field. He's the most important thing in the world to me, but he has to have a quality of life. While the Lyme Treatment has helped just about everything else (his stifles, his back, his attitude), not being able to walk comfortably defeats all of that.
I don't know enough about Cushing's to say that I am sure he DOESN'T have it, but I've seen so many Cushing's horses and my horse isn't presenting like any of them. Even the chronic laminitis and Cushing's horse I knew had the curly wavy body-clip-in-July coat. I don't deny the laminitis--I can see it with my own eyes and I know when my horse is footsore--but the cause?
He's a hard keeper, tending to be more thin and has never been FAT. He's barely 1,000 pounds at nearly 16 hands. Isn't IR characterized by, well, weight? Gaining weight off air?
Cushing's can't be tested in the fall because of naturally heightened cortisol levels...I know insulin can but he has to get extra hay and roughly 6lbs of grain a day out of work to keep some sort of weight on him.
That is flat-out untrue, your assertion "Cushing's can't be tested in the fall because of naturally heightened cortisol ". First off, Cushings or PPID is diagnosed by endogenous ACTH, and although there is a seasonal rise in ACTH, that is normally dealt with in Cushinoid horses by increasing their Pergolide dosage.
Thin horses can be Insulin Resistant, although T'breds are not normally as prone to it as other breeds. Untreated PPID can, however, cause IR. A 17 year old horse is at prime age for Cushing's dx. You (original poster) need to see the yahoogroups.com message group Equine Cushings and Insulin Resistance for help on how to properly determine which problem your horse has. That list is a goldmine of information, including that Pergolide can be obtained very cheaply from a couple of compounding pharmacies that are known to be reliable, data is available in the files of that group.
RIP Sasha, best dog ever, pictured shortly before she died, Death either by euthanasia or natural causes is only the end of the animal inhabiting its body; I believe the spirit lives on.
I have always heard that you can't test a horse for Cushings in the fall...from multiple vets.
That's interesting that undiagnosed PPID can cause IR, because another recent post asserted that IR can cause Pedal Oseitis which my horse was diagnosed with last year...
I just went out to the barn and moved him to the non-grass field. I'll probably switch barns this winter to somewhere that is a little more accommodating to his needs. He won't touch beet pulp at all, but I have consulted with Purina, my feed guy, and my vet that Ultium is OK for laminitic horses. I have a very difficult time keeping weight on this horse, and without grass, it will be that more difficult.
I will definitely check out that Yahoo group...
So even if he's not displaying ANY other symptoms, other than the laminitis, for Equine Metabolic Syndrome/IR or Cushing's Syndrome, you guys believe this is the root cause?