The Horse.com Ask the vet live: Equine Cushing's Disease (PPID)

9/18/2012

Some good points were raised during TheHorse.com's Ask the vet live: Equine Cushing's Disease sponsored by Boehringer Ingelheim on 18 September, with questions being answered by Dr Nicholas Frank and Dr Marian Little.

In particular:
- important to recognise early and advanced PPID symptoms, early signs are often subtle and variable and include late shedding of winter coat, patchy longer/lighter coloured hairs, regional fat deposits, loss of topline, easy keeper becomes hard to keep weight on, depression & lethargy, footsoreness and chronic laminitis.
More advanced signs include "woolly mammoth" hair coat, recurrent infections e.g. hoof and tooth abscesses & sinusitis, excess drinking/urination, abnormal sweating.

- Miller graded pituitary glands into 1 and 2 = normal, 3 = mild PPID, 4 = moderate PPID and 5 = advanced PPID. Diagnostic blood tests only picked up grade 5 and some grade 4 cases of PPID, but mild and moderate PPID cases are generally not detected by current testing. If a horse has clinical signs but negative test results, keep testing as eventually a positive result is likely.

- Horses that are obese and have EMS are predisposed to PPID.

- ACTH is the easiest screening test and autumn is the best time to test using seasonal reference ranges for ACTH. TRH stimulation test (of ACTH) may be a more sensitive test for diagnosing early PPID cases.

- Horses may need increased pergolide during the autumn seasonal rise - test ACTH to check control of PPID. Even when diagnosis is obvious from clinical signs, testing ACTH gives a measure of severity and response to treatment.

- caring for the PPID horse includes giving pergolide, checking insulin levels, good nutrition (vitamin E and anti-oxidants), hoof care, clipping, deworming, regular dental checks, exercise if possible.

- not all horses with PPID are insulin resistant - insulin should be tested (basal insulin and glucose and/or oral sugar test) to make informed decisions about nutrition, e.g. able to graze or not. Not all horses with PPID will get laminitis - laminitis is connected to insulin resistance. If not insulin resistant, many older horses do better on grass.

- every case of PPID is different and must be managed individually.

Listen to the archived recording at www.thehorse.com

Read notes of the session

4 Comments

Chris Rosson

1/16/2016 10:14:07 am

My 11 yr old horse has Cushings Disease and has had one episode of laminits. She is on Prascend and I believe it has affected her appetite. She eats hay and limited grass happily and I feed her tablet in a carrot. I try to fed her Lo-Cal feed balancer to ensure she get adequate vitamins and minerals but she doesn't always eat it. I have tried every feed and supplement for laminitis prone horses but she won't eat any of them nor will she eat treats. She used to have a good appetite.This is good from a calorie controlling point of view but I'm concerned she isn't getting adequate vitamins and minerals. She looks well, has lost weight but is a little lethargic, due to the Cushings, and dozes in her stabke after exercise. Should I be concerns or just carry on?

The Laminitis Site

1/20/2016 10:39:04 am

Hi Chris

It appears to be fairly unusual for the correct dose of Prascend to affect appetite, once it has been correctly introduced to a horse by slowly increasing the dose. Sometimes when inappetence is seen, it appears to be because the dose is too high - perhaps for that time of year (as many horses appear to need a higher dose during the seasonal rise, with a subsequent reduction in dose after the seasonal rise) - or rarely because an incorrect diagnosis of PPID has been made. See http://www.thelaminitissite.org/2/post/2014/03/starting-pergolideprascend.html

We have also recently noticed a relationship in some horses between the timing of the Prascend and the timing of their bucket feed. Some horses seem to go off their feed if they have their Prascend just before their feed, but eat their feed at least 6 hours after having their Prascend, other horses like to have their Prascend and feed at the same time, so it may be worth experimenting with when you give her her Prascend in relation to her bucket feed.

What clinical signs of PPID was she showing at diagnosis, and what if any is she still showing? A diagnosis of PPID cannot be made on ACTH levels alone - clinical signs must be present. See http://www.thelaminitissite.org/articles/pituitary-pars-intermedia-dysfunction, http://www.thelaminitissite.org/2/post/2014/02/is-it-ppid-or-is-it-ems.html, http://www.thelaminitissite.org/articles/video-comparing-ppid-symptoms-and-normal-aging. If she wasn't showing signs specific to PPID but had an above normal ACTH result, be aware that stress (e.g. illness, pain, exercise, travelling, use of a twitch, fear of vets/needles, dental procedures...) and some medicines (e.g. some sedation drugs and Ventipulmin) can increase ACTH. You mention that she is lethargic - lethargy is usually one of the first signs of PPID to resolve with correct treatment, so ensure her dose of Prascend is fully controlling her clinical signs as well as her hormone levels, and ensure she isn't overweight, as being overweight can make horses lethargic.

As she has had laminitis, she will also have (or have had) EMS, so hopefully you are testing her insulin levels regularly as well as her ACTH - see http://www.thelaminitissite.org/articles/testing-insulin and http://www.thelaminitissite.org/articles/equine-metabolic-syndrome-and-insulin-dysregulation. Have you had x-rays taken to check for any rotation following her laminitis - it is important to always have x-rays taken - we regularly see horses who did not have x-rays taken following laminitis, and who, when finally x-rayed, have long-term rotation which has led to bone loss. See http://www.thelaminitissite.org/articles/laminitis-and-the-feet.

Here are our diet suggestions: http://www.thelaminitissite.org/diet.html - our preferred balancer is Spillers Lite, based on the mineral analysis. If the above suggestions don't help, you might try carrying out a taste test, by offering her all the components of her feed individually to see what she will eat, then slowly re-introducing anything she isn't so keen on. Sometimes owners only feed a small amount of chaff or sugar beet to carry minerals, and increasing this "carrier" can help to disguise the taste of the minerals. You could try mixing the LoCal with something she will eat before mixing it into the feed, such as micronised linseed or her salt, and make sure her feed is well mixed when dry before adding water and mixing it, as mixing minerals wet can lead to them clumping (although this tends to be more for powder minerals than pellets). Top dressing the mixed feed with something she finds tasty (i.e. sprinkling it on top of the mixed feed) can also help. Otherwise will she eat the Lo Cal from your hand as a treat - if you have another horse for competition, this can help to encourage a horse to eat (with the other horse at a safe distance to prevent any injuries). You could also try sprinkling the Lo Cal over her hay.

She will need a good mineral/vitamin supplement/balancer, so worth persevering.

You might like to join our Facebook support group - questions like yours come up regularly and other members often have good ideas -https://www.facebook.com/groups/475349259169277/.

Andrea

Disclaimer: The information, suggestions and links (hereafter referred to as “information”) contained in this post are provided for information purposes only and should not be relied upon nor replace professional veterinary advice. Information is non-veterinary, is based as far as possible on current research, does not constitute advice or diagnosis, and should be discussed with all relevant vets and hoofcare or other professionals. No responsibility is taken for the accuracy or suitability of information contained in this post, and no liability accepted for damages of any kind arising from use, reference to or reliance on any information contained in this post. If you suspect your horse has laminitis or is ill, please consul

Michelle Lawrence

9/12/2017 08:50:53 pm

Hi, my cushings horse is 24, he is on 1 prascend a day, but he has deteriorated fairly rapidly over the last few months, he has become incontinent, which has really been an issue throughout the summer, with me having to wash his hind legs constantly as the urine was making his legs sore, I ended up having to bandage them as the flies were then attacking his legs and causing more sores, making him truly miserable. I worry about what I'm going to do with him in the winter as he lives out (too unsettled in the stable) and he will most definitely end up with mudfever, i dont think i will manage to keep it at bay under the circumstances, and now he is really struggling with his hind legs due to muscle wastage on top of his arthritis (which has become worse with the medication as he isn't producing as much cortizone) I'm just wondering wether your advice would be to pts before he gets any worse- I suppose I'm looking for reassurance that this would be the kindest thing for me to Do 😐

The Laminitis Site

9/14/2017 06:10:10 pm

Hi Michelle

It sounds as if you need to consult the vet treating your horse – only he or she can advise you on this. You might ask whether your horse’s health can be improved, through further diagnosis and treatment, and you may have to consider whether you can afford this.

Are you sure that the clinical signs your horse is showing are all due to PPID? Incontinence is not a clinical sign that is usually associated with PPID – has your vet investigated other reasons for this? See: http://veterinarycalendar.dvm360.com/urinary-incontinence-drippy-problem-proceedings?id=&pageID=1&sk=&date

If his muscle wastage is due to PPID, is his PPID perhaps not being controlled by 1 mg Prascend per day – does he require a higher dose? Are his resting ACTH results within the normal range for the time of year? Again, you should speak to your vet about ACTH results, clinical signs and adjusting the dose of Prascend accordingly. Many horses will need an increased dose during the seasonal rise (peaking August to October in the northern hemisphere). The dose a horse requires may depend on how advanced the PPID was when treatment was started – the earlier PPID is diagnosed and treatment started, it seems the more likely it is that lower doses of pergolide will control clinical signs.

Treatment with Prascend may make arthritis seem more obvious. This is thought to be because some of the hormones produced with PPID have anti-inflammatory and pain relieving effects, so as PPID horses become more arthritic this isn’t particularly noticed because the PPID hormones mask the effects, but when effective treatment starts, the hormone levels are reduced and the clinical signs of the arthritis are seen. PPID doesn’t appear to increase cortisol levels in most horses, so treatment with pergolide won’t necessarily reduce cortisol levels.

Is his diet providing him with above minimum levels of nutrition – see http://www.thelaminitissite.org/diet.html but again talk to your vet.

Horses with PPID, where the PPID is brought under control through treatment and management, often live long healthy lives, so do discuss with your vet whether your horse might have illnesses in addition to the PPID, and whether treatment of his PPID can be improved.

Good luck.

Andrea

Disclaimer: The information, suggestions and links (hereafter referred to as “information”) contained in this post are provided for information purposes only and should not be relied upon nor replace professional veterinary advice. Information is non-veterinary, is based as far as possible on current research, does not constitute advice or diagnosis, and should be discussed with all relevant vets and hoofcare or other professionals. No responsibility is taken for the accuracy or suitability of information contained in this post, and no liability accepted for damages of any kind arising from use, reference to or reliance on any information contained in this post. If you suspect your horse has laminitis or is ill, please consult your vet. This disclaimer applies to all future communications/posts.

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The Horse.com Ask the vet live: Equine Cushing's Disease (PPID)

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