Equine Cushings Disease
AKA Equine Pituitary Adenoma
As many owners of horses & ponies will testify the quality of life of our animals is paramount. Thus it is very perplexing as an equine veterinary surgeon in this animal loving country that so many cases of this distressing disease either go unnoticed or more alarmingly untreated when diagnosed.
This very simple blog is just a basic synopsis of what to look out for if you are suspicious that your horse has Cushing’s. Then at the end a short overview of the currently available medical treatments are briefly evaluated based on current veterinary evidence.
What is Cushing’s disease of the horse?
Put very simply Equine Cushing’s disease/syndrome is an excess production of steroid by the adrenal gland of the horse.
Why does it happen?
To explain why it happens one has to understand the normal production of steroid in the body, remember we all need some steroid to live and function properly and our horses are no different.
Cortisol (the steroid produced by the adrenal glands of the horse) is produced when it is told to do so by a hormone called ACTH released from the brain. This production of ACTH is stopped once cortisol is produced, so the cortisol acts as a controlling balance mechanism within the body telling the brain to reduce the production of ACTH.
When this mechanism goes wrong, as in Equine Cushing’s disease/syndrome, that’s when the problems start. In Cushing’s disease/syndrome it is usually a problem in the brain of the horse. A small tumour causes an unregulated production and therefore release of ACTH.
This then tells the adrenal gland to produce cortisol but unlike in the normal horse the newly produced cortisol does not tell the brain to shut down the ACTH production. Therefore ever increasing levels of ACTH allow more and more steroid to be produced and enter the blood leading to the disease of Equine Cushing’s disease/syndrome and all of its distressing clinical signs.
So what are the suspicious signs of Equine Cushing’s Disease/Syndrome and what horses are more likely to be affected?
The following are some of the more commonly seen signs with Equine Cushing’s disease/syndrome but it is by no means an exclusive list, nor will every horse with Cushing’s exhibit all of these signs. Indeed there are other clinical signs not mentioned and it is for these reasons that this blog should in no way replace the clinical judgement of your vet with whom you should liase closely.
Secondly if you are going to successfully get to the bottom of this disease then you, your vet and your farrier (most likely) will have to work very closely to treat and manage this disease.
Some frequently reported signs:
- Not an uncommon disease of horses over 15 yrs (rare in the younger horse)
- Greatest incidence amongst the 20-25 year olds
- Mares seem to more affected (reasons not known)
- Polydipsia (drinking more) & polyuria (peeing more) these often go unnoticed
- Glycosuria (glucose in urine)
- Hirsutism (abnormally dense or hairy coat)
- Hair abnormally long, curly or brittle
- Density of hair can be exceptionally high
- Normal seasonal shedding of hair often does not happen
- Sweating and or weight loss is often common
- Not easy to notice amongst the dense coat
- Infections (respiratory/tendon sheaths/joints/oral ulcers) are not uncommon
- Minor wounds often fail to heal or heal poorly or very slowly
- Dramatic weight loss/muscle weakness/lethargy are commonly noted
- Reproductive cycles in mares are often interrupted or are abnormal length
- Some mares will lactate while not pregnant or nursing foals
- Laminitis (frequently) & colic are often seen in the later stages of this disease
- Bulging fat pads are often seen above the orbits of the eyes
- Some horses may even go blind (albeit this is not common)
So how do I find out if my horse has this disease?
If you are worried about your horse having Cushing’s then you must liase with your vet. He or she will be able to add to the details described above. They may also help rule out other common causes to the signs described above.
Your vet will have a fair clinical suspicion (as will you) that this is a possible cause and thus an accurate diagnosis may be sought. This will involve a blood sample(s).
There are many tests that can be done but from my experience the most accurate blood tests involve testing for these four parameters on an overnight fasted horse:
- Basal cortisol levels
- Insulin levels
- Glucose levels
- ACTH levels
1. This ACTH sample must be spun/separated and frozen within a half hour of sampling and must be sent frozen to the laboratory. This is the current Laminitis Trust recommended blood test method of diagnosing this form of Equine Cushing’s disease.
What can I do once my horse has been diagnosed with Cushing’s?
There is no surgical cure for Equine Cushing’s disease/syndrome as it is a tumour in a part of the brain that is extremely difficult to get access to. Thus medical and farrier management is the current treatment of choice although herbal treatments such as “Monks Pepper” may also be investigated. Further details of this possible option can be obtained on request, please email us at info@vetmedsplus.co.uk
Like all medical problems it is often better to treat earlier than later. There are a few treatments that are useful but unfortunately all are expensive. Another problem is that there are no currently licensed products for the treatment of this disease in this country. It is my understanding that this may change in future and we will post them if or when they become available.
There are a few human medicines that are not licenced for use in horses although have very good results in helping control Cushing’s Disease. As they are not licenced for use in horses we are unable to list their names in this article.
I hope you have found this useful. If you have any comments please submit them to our blog and we will publish them on the website. If you have any questions please feel free to email us at: info@vetmedsplus.co.uk
October 12th, 2006 at 11:36 pm
Hi, just read the blog and this is so like what my little shetland Ailey had, I thought it was just an old age thing. she was over 20 afterall, we never knew her exact age as she was a rescue case.. she was so lovely …..but in the end we couldn’t see her suffer any more, initially it was just periodic laminitis episodes, the vets that saw her said it was the lush grass and to be honest it may have been that initially….. anyway despite numerous non successful treatments over many months with bute / sedalin etc…. we (my kids and I) decided to have her put to sleep, it was before all this fuss about passports and the like …. she’s under the oak trees by the river now….. not quite the highlands but she should be happy there….. my advise to anyone reading this is to not wait and see, encourage your vet to consider the less obvious possibilities….. from what I gather this is a successfully treated disease in a lot of cases….
May 12th, 2007 at 6:40 am
H suspect my American Saddlebred Gelding, 18-19 years is developing Cushings Syndorme. He looked like an overgrown Shetland pony this winter. His hair is slow to shed ono his barrel. It comes out when you tug at it. He is slowly loosing his winter coat, his cortisol level is off and that is all I know.
His stamina is down and he sweats more with activity than previously.
Any help would be appreciated.
Thank you,
Carol Biggs
June 29th, 2007 at 11:31 am
Dear Carol Biggs,
I have a quarter horse/ English thoroughbred who has Cushings - diagnosed 5 years ago -he is now 29 years old and well. If you are not into drugs as I am not try herbal remedies - you neeed to boost his immune system so try echinaecia - 30ml per day in liquid form for 2 weeks plus chasteberry in liquid form as 15ml per day. Put him on a sugar free diet which is also low in carbohydrates. Plenty of hay and keep off grass early in the mornings when the sugar levels are high. The echinaecia should be stopped for a week after 3 weeks to allow the horses own immune system to kick in. Then it should be fed at about 10ml every day. I feed it for 2 weeks then have a weekend off. If your horse has problems with breathing try using cold liver oil at about 10ml twice a day.
Clipped all of his coat off - legs and all and rug as necessary to maintain his body temperature - he should wear the same amount of clothes as you wear on a day to day basis in othher words if it is chilly you put on a sweater so he may need a lightweight rug, etc.
I friend of mine rang me 2 weeks ago to say her mare had just be diagnosed and what had I done - her mare was depressed and they were thinking that they may have to take the ultimate action, however with treating her as above my friend rang last night to say the mare was trotting round the field and was a changed horse.
It is a bit trial and error to start off with but my horse looks stunning this year and is a very happy person.
Sue Spackman
Devon, UK
September 11th, 2007 at 1:20 am
I have an arab gelding who has had cushings for over 5 years. He is now 25. I’ve tried different diets, supplements, pergolide, special shoeing. Last year’s acth level was 72. This year’s was 464. I’m not ready to lose him. Please send me a copy of your report. I would do anything for this guy.
September 17th, 2007 at 1:13 pm
Could you send me a copy of your report, Sheryl, I have a 29 year old TB who was diagnosed earlier this year. He is losing weight and I seem to have tried all the conventional management stuff, so anything you could suggest would be helpful.
September 19th, 2007 at 9:30 pm
Sheryl,
Please send me a copy of your report. Our shetland has Cushings. He has always had a laminitis problem but this year it won’t go away. He has also failed to lose his coat and there are other worry signs. He is about 19 and is my 4 year old’s best friend. Any help would be welcomed.
October 1st, 2007 at 7:27 pm
Hi Sheryl
Could you please send me a copy of the report, I am treating my 19 year old with Pergolide every other day at the moment.
Many Thanks
October 4th, 2007 at 9:12 am
I have read with interest your blog on Cushing’s in horses.
I have owned my 15.00hh Arab/New Forest gelding for 24 years - he is now 27 and most probably has Cushings although I have not had him tested. His only symptom at present is the heavy coat. Previous summers, I have clipped him out completely but the weather as it has been this summer, only gave him a “trace clip”. As a consequence, the previously unclipped hair above the trace line is now excessively heavy.
My query is, do other owners completely clip out their Cushing’s horses through the winter? If so, are they still able to live out, albeit rugged, in reasonable winter weather? (My horse is stabled at night in any event in really bad weather). At the moment, I have trace clipped him but he is still sweating - I only rug him at night or when it rains.
He is well and still enjoys hacking out two or three times a week with the occasional canter!
I would be most interested to know what other owners do.
Lin Uglow
Devon
October 13th, 2007 at 9:22 pm
Hi Sheryl,
Have just had my 16yrs old Dales mare confirmed with Cushing’s. She’shad persistent laminitis for the first time this summer. No other symptoms to speak of, she was fat and cresty, but this has now changed with diet and box rest, but the laminitis persists. Just started pergolide so would be really interested in reading your report. Would very much appreciate a copy.
October 19th, 2007 at 10:03 pm
Hi Sheryl,
My pony has recently been diagnosed with Cushings, and from articles I’ve read I think he’s in the latter stages of it as he has very bad laminitis. We are about to start him on pergolide, but i was extremely interested to read that you have found a way to reverse it.
PLEASE tell me what you did!! I would love a copy of your report.
I look forward to hearing from you.
Many thanks,
Debs x
November 8th, 2007 at 11:03 pm
Dear Sheryl,
My 24 year old pony has been diagnosed today. He has always had a heavy coat and has had laminitis twice but a few years ago, so it was difficult to believe that this time it was different, I have never seen him look so down.
The vet has reccomended pergolide and I had already started supplementation to improve his immune system as he has had a sheath infection which took longer than normal to clear up. I would be so grateful if you could send a copy of your report as he has been such a star. He worked in a riding school for 10 years and deserves his long and happy retirement.
Many thanks for giving mr some hope,
Lis
November 12th, 2007 at 6:58 pm
Sheryl,
My vet last week stated she thinks my horse, an 18 yo Arabian mare, has Cushings based on cresty neck, fat pads on shoulders and at tail head . She also has laminitis that flares if she looks at green grass. The test to confirm is $125 plus trip and the pergolide is $90 a months to treat. Is this the usual cost? Is there a less expensive source? I am happy to do this if it helps her but also want to try your echinacea. Can I make an infusion myself? The only sources I know are little bottles that are very expensive but I can buy the root and make an infusion. Any words of wisdom on that? Thank you for the blog.
Jan
November 12th, 2007 at 9:46 pm
Dear Sheryl
My 23 year old Irish Draught X Thoroughbred threw a long coat last year and had dreadlocks under his belly this Spring. I clipped him in the Summer as he does not like to be sweaty and as I write this, he is clipped apart from his head and legs to make him comfortable. He was sweating on top of his coat and I knew he needed to be clipped as our first pony had cushings and I knew the signs. Our vet has confirmed that she thinks he is in the early stages and has offered a blood test. Otherwise he eats well, has not lost condition, but I am mindful of keeping his flu tet up to date, worming etc.
I would really like a copy of your report as I would like to ride him when I take early retirement in 22 months time, when I planned to spend more time with him. I only hope that I get the chance.
Many thanks
Caroline
March 9th, 2008 at 1:10 am
Dear Sheryl
I have a Morgan who has been on Pergolide for almost 2 years. He is starting to have more and more frequent episodes of laminitis. He laos is progressing with other symptoms sweating, long curly coat, excessive urinating, etc.. I would love a copy of your report if he can be helped. I know he is pretty uncomfortable right now.
thanks,
Sue
April 9th, 2008 at 8:31 am
Dear Sheryl
Please could you send me a copy of your report? My 20 year old tb/newf forest has been showing slight signs of Cushings over the past couple of years. He’s drinking lots of water, loosing weight, fat pods above his eyes and is having too many ‘OFF’ days at the moment and the vet thinks it’s cushings but just waiting for a test date.
Many thanks
Jo
April 16th, 2008 at 3:00 am
Dear Sheryl,
I have a a QH that was diagnosed with Cushing 3 years ago at age 9. He is on Pergolide that I order form Wedgewood RX. It doen’t seem to work as well as the human pills that were available. He has lost his top line, his energe level is low and we are going down hill fast.
PLease send me a copy of your report.
Thank you,
Diane
May 13th, 2008 at 7:55 pm
Hi Sheryl
could you please send a copy of your report, I have just taken on a pony who I thought was just under weight and generally not cared for, but have since found she has cushings. She’s looking a whole lot better now with good diet and grazing management but is still very lethergic and depressed looking !! I have been looking at the supplement Hormonise, wondered whether any one else has tried it ?
I’d be grateful for any info on anyhting cushings related
Thanks
Hayley
June 2nd, 2008 at 2:30 pm
Hi everyone,
Its quite nice to find a web site like this. I am looking for some advice…. My 28year old mare has been diagnosed with Cushings - a few weeks ago now and my vet advised me to start Pergolide .75g per day and she has had a bit of \ tough tie of it since she has sarted them. About 48 hours later she started to loose her appetite, something which never happens with her!!! She would usually eat anything, we had to disguise the tablets in everything and anything to get them in her, now i have to disolve them in apple juice and suringe them into her!!! Little monster! I was wondering if anyone could ell me how long befoe she picks up again and starts eating properly, im sure ive thrown away about a whole tub of cortaflex by now!! Shes been on them about 2 and a half weeks now and she had a really bad time in between - last weekend where she woudlnt eat anything, she wasnt drinking and looked so depressed, it was horrible, she has picked up again but now shes lost interest in her feed again, still trots down the lane to the field of a nighttime though!! She is fine with the grass but not her dinner. I was thinking abot introducing sugar beet to her dinners to make them a bit nicer, at the moment she has her usual bucketof happy hoof and supplements whcih she has been on forever!
Any comments etc would be lovely.
Tahnks very much and I hope everyones horses/ponies are all happy and healthy
Claire
July 18th, 2008 at 2:39 pm
Hi Sheryl
Could you please send me a copy of your report. I have a 21 year old ID XTB who was diagnosed with cushings last year and has been on Pergolide. Her coat is already over 4cm long and it’s not even winter yet, she did shed her winter coat but it took a long time.
I have noticed over the past week that when she is hot or has been ridden only lightly she is panting quite heavily, but after a hose down or 10 minutes rest her breathing returns to normal.
Looking forward to receiving your reports.
Sam Dove
September 25th, 2008 at 7:07 pm
Hi
We have just found out that our pony has crushing. The vet has put her on Pergolide, her feet are really bad with laminitis will the Pergolide help with the pain or do we need to give her pain relief as well? She is still eating well but just don’t like seeing her the way she is. Normally she is a happy pony but at the moment she seems really down. Could you send me anything that might help.
Thanks Lisa.
October 15th, 2008 at 10:28 am
Following several bouts of unexplained laminitus my vet suspects my 17yr old Welsh Section A, who has been part of the family for 14 years, has cushings. He has not been tested as I am advised tests are not conclusive if done at this time of year. The vet has suggested putting him on Pergolide but from what I have read about the side effects I am not sure about this.
I am most concerned about the laminitus as it causes him so much pain and distress. Can anyone recommend a different but effective way forward
Sue
October 23rd, 2008 at 1:28 pm
My daughters pony has recently been diagnosed with Cushings. She is 17 years old and has a very woolly coat. She has had laminitis before and now has it again quite badly which worries me.
The vet has recommended pergolide which we are about to start, but I was extremely interested to read that you have found a way to reverse it. I would love a copy of your report.
I look forward to hearing from you.
Many thanks,
Caroline
February 25th, 2009 at 10:58 am
Hi Sheryl,
Please could you also send me a copy of your report?
My 22yr old Arab Gelding was diagnosed with Cushings 3 months ago. His only symptoms were laminitis (very sudden and never had it before) and fat pockets, although he’s always been a good doer!
His first bloods came back as slightly raised ACHT and moderately raised Glucose, although nothing to cause major concern.
He was put onto 1mg Pergolide immediately and after 2 months on box rest he was no better and more bloods taken. His Glucose was now 67!
The vet increased his Pergolide to 2mg and he was re-tested last Friday! His Glucose and all other levels are normal
However, his ACHT has gone up to 160!!
He is still very lame and my vet has increased his Pergolide to 3mg!
He is losing weight slowly on a diet of soaked hay, D&H Safe and Sound, Kwikbeet (no sugar) and Danillon (2 per day).
Any advice or help would be greatly appreciated!
Kind regards,
Sarah
October 24th, 2009 at 10:40 am
Hi
My mare is 24, I have suspected cushings for the last couple of months, she is going for a test once she has got over this bout of laminitis, I would really appreciate some help with the herbal remedies, Im not sure what to use and at what quantities.
Any advice would be greatly appreciated.
Regards
Jayne