A practical guide to body condition scoring horses - Dr Teresa Hollands 

This video by Dr Teresa Hollands - as shown in the October 2013 The Laminitis Revolution 2 webinar - shows how to body condition score your horse, using the modified 0-5 point scoring system . Horses that are too thin, too fat and just right are used to demonstrate how to assess BCS, including a typical underweight PPID horse and a typical overweight EMS/PPID pony.

The body should be divided into 3 sections: neck, middle and bottom, and each section scored separately by feeling for fat over the skeleton. 3 is the perfect score. Body condition scoring should be carried out ideally every 2 weeks on all horses, and the results recorded.

Neck - there shouldn't be any fat or crest above the nuchal ligament - there is no muscle above the nuchal ligament, anything felt here is fat, not top line. A large crest will score 4 or more, bulges and corregation in the crest will probably score 5.
The shoulder blade should be well defined - if you run your hand down the side of the neck, it should come to a stop at the shoulder blade.

Middle - you should be able to feel the ribs, like feeling stair banisters through a velvet curtain, but hardly see them. If you can neither see nor feel the ribs, that scores 4 or more. 
If you place your hand over the backbone, it should form a nice curve - a triangle is too thin, flat is too fat.

Bottom - you should be able to feel just feel the top of the pelvis, the hip bone and the tail bone. If you can't see or feel these bones, that scores 4 or more.

Research has shown that if a horse is overweight, for the all fat that is visible or can be palpated under the skin, there is probably the same amount inside the horse that can't be seen, wrapped around the organs and killing the horse from the inside.

In summary, if you can feel AND see bones, the horse is too thin.
If you can neither feel nor see bones, the horse is too fat.
If you can feel but not see bones, the horse is just right.

Clinical symptoms of PPID v signs of normal ageing - Dr Jo Ireland

Dr Jo Ireland demonstrates some of the symptoms of PPID and explains how to differentiate between normal ageing changes and changes that should make you suspicious of PPID. This video was shown in the October 2013 The Laminitis Revolution 2 webinar.

It's not uncommon for horses to have a deepening of the hollows above their eyes, more grey hairs around their head and some loss of muscle tone as they get older.

However, pronounced muscle loss along the neck, back and over the hind quarters is suggestive of PPID, as is the development of a pot belly.

The long curly hair coat that doesn't shed is a classic sign of PPID, but this is usually only seen in advanced cases. Warning signs for PPID include more subtle hair coat abnormalities, such as the summer coat being longer or thicker than normal, or long dull coarse hairs in the coat.

Patchy sweating can also suggest PPID, this may be due to an excessively long and thick coat, but can be seen in horses with PPID that have normal coats as well.

Horses with PPID may show signs of chronic laminitis, such as divergent hoof rings.

A common indication of PPID is accumulation of fat under the lower eyelid, giving a puffy appearance to the lower eyelid, and fat may also sometimes be seen in the hollows above the eyes.

Horses with PPID often show few symptoms in the early stages and symptoms vary between horses. If you are at all worried, talk to your vet.

For more information about the clinical signs of PPID, diagnosis and treatment, see Pituitary Pars Intermedia Dysfunction.

Pre-sale has begun on a newly edited paperback version of the book Care and Rehabilitation of the Equine Foot for $90. The high-quality paper and stitched binding has been kept, but with the new soft cover it weighs less than four pounds, meaning that international customers will enjoy much cheaper shipping rates. Pre-sale books should be mailed next week. 

TLS recommends that everyone involved in the trimming and rehab of a horse with laminitis has - and reads - this book! See TLS's review of the book. 

Articles about coffin/pedal bone rotation/sinking by Pete Ramey that recently appeared in Horseback Magazine.

Recognizing Coffin Bone Rotation

Sinking Coffin Bones

How to Reverse Coffin Bone Sinking

The full list of Pete's articles to date for Horseback Magazine

Information about neurological symptoms relating to PPID has been added to the website. Ataxia (weakness/inconsistent gait), blindness, seizures and narcolepsy have been associated with advanced PPID. Blindness has been suggested as being caused by adenomas (tumours) in the pituitary gland compressing the optic nerves, but there doesn't appear to be a known connection between other neurological symptoms and PPID. TLS queries whether direct trauma to the head/brain could play a part in both PPID and these rare neurological symptoms.

The majority of Dianne McFarlane's excellent review of PPID from 2011 can be read on Google books, covering the anatomy and physiology of the equine pituitary gland, epidemiology, pathophysiology and clinical signs, and the start of the section on diagnostic tests for PPID. Not much has changed since 2011, although it's worth bearing in mind that autumn (Aug-Oct) is now considered by many to be the best time to test ACTH to diagnose PPID, as long as a seasonally adjusted reference range is used. Also, no doubt due to increased testing and awareness, horses aged 10 and under are being diagnosed with PPID, and there is thought to be no breed or gender predilection.

McFarlane goes on to say that measuring ACTH and alpha-MSH are useful in the diagnosis of PPID (measuring ACTH is now the most widely used test for PPID in the UK), and that the TRH stimulation of ACTH may be useful (compared to measuring cortisol - further research has been done since McFarlane's paper was published and the TRH stimulation of ACTH is now recommended as a second-tier test when resting ACTH results are equivocal). Insulin is suggested as being increased in around 60% of PPID horses, and monitoring fasting insulin is recommended for all PPID horses to predict laminitis risk. It is suggested that cortisol circadian rhythm loss, urinary cortisol/creatinine ratio and ACTH stimulation test are poor tests for diagnosing PPID. Treatment suggestions include aggressive preventative health care (tooth and hoof care, nutrition, parasite control, clipping, rugging, shelter), and treatment with pergolide. Cyproheptadine is mentioned for possible use in combination with pergolide when pergolide alone doesn't control clinical symptoms, and Trilostane for possible use in horses with hypercortisolemia. Natural remedies, specifically Vitex agnus castus, are warned against due to the lack of evidence of efficacy and safety.

Points we found of particular interest:
Alpha-MSH (increased in horses with PPID) is a potent anti-inflammatory - some owners report increased signs of arthritis and similar problems when horses start treatment with pergolide - is this because "natural" anti-inflammatory levels are reduced?
Similarly beta-endorphin (also increased in horses with PPID) has pain relieving and anti-inflammatory effects.
CLIP (another hormone increased in horses with PPID) stimulates the release of insulin in rodents - this hasn't been studied in horses. Could this be causing laminitis in horses with PPID?
20% of horses testing positive for PPID using ACTH and/or alpha-MSH had no clinical signs of disease - did they really have PPID or were these false positives? We are often asked whether horses with above normal ACTH results but no clinical symptoms should be treated.
McFarlane suggests it would be interesting to study the geographical incidence of PPID cases, and that finding a pattern might suggest that environmental exposures may predispose to PPID, as exposure to agricultural chemicals has been shown to predispose to Parkinson's disease in humans. We know of several owners/yards with what appears to be a greater than normal number of PPID horses - are environmental/management factors involved?
It's now well accepted that PPID is a dopaminergic neurodegenerative disease, and that oxidative stress may contribute to neuronal damage and death.
The mechanisms causing the symptoms of PPID are mostly not understood.
"It is conceivable that PPID is a collection of syndromes each with a unique set of clinical signs and hormone profiles" - this may explain why horses with PPID can have such different symptoms and blood test results, and emphasises that each horse must be treated as an individual. It is also unlikely that one testing method will be ideal for every case of PPID.
Obesity and insulin resistance cause oxidative stress, which may cause PPID. 
Alpha-MSH, beta-endorphin and ACTH all suppress the immune system, possibly causing the increase in infections and parasite burdens often seen in horses with PPID.
Horses with PPID are often lethargic - this could be because of insulin resistance, other diseases due to PPID, or increased beta-endorphin levels.
PPID horses with laminitis often appear to have low-grade laminitis, but this may be because their pain threshold is higher due to increased beta-endorphin levels. They could still be at risk of significant damage.
The diagnosis of PPID is not straightforward!
False negative test results are common in the early stages of PPID, and it is likely that significant effects of the disease have already occurred by the time tests diagnose PPID.
If a horse shows symptoms of PPID but blood tests are negative, repeated testing is recommended.
At post mortem, the pituitary gland of a horse with PPID can be 2 to 5 times the normal size, and compression of other parts of the pituitary gland and rarely the optic chiasm (through which the optic nerves pass) and the hypothalamus can be seen. Evidence of damage may be seen in other organs such as the heart, liver, kidneys and lungs.
And finally, to end on a positive note: "when well cared for, horses with PPID can live into their 30s and even 40s".

For notes of Dianne McFarlane's presentation at the Equine Endocrinology Summit 2011 and a link to view the presentation, see: http://thelaminitissite.myfastforum.org/about126.html

New research by David Rendle et al. into the pharmacokinetics of pergolide was published in the Equine Veterinary Journal supplement Clinical Research Abstracts of BEVA September 2013. 

Rendle DI, Hughes KJ, Doran G, Edwards S
Pharmacokinetics of Pergolide Mesylate in Horses
Equine Veterinary Journal Volume 45, Issue Supplement S44, page 19, September 2013

8 healthy horses were given 0.02 mg/kg bodyweight pergolide intravenously - this is the equivalent of 10 mg for a 500 kg horse - ten times the recommended starting dose of 0.002 mg/kg bw, or 1 mg/500 kg horse. The abstract doesn't say whether it was a one off dose - presumably it was. Blood was analysed for pergolide concentrations for 48 hours following administration. 

The mean half life was 5.8 +/- 2.26 hours - shorter than previously reported, but in line with the mean half life of 5.86 +/- 3.42 hours found by Abra Wright when healthy mares were given 0.01 mg/kg pergolide by mouth after fasting (5 mg/500 kg horse). In Wright's research there was a large variation of half life between horses - from 3.10 to 12.39 hours. There was also a difference in maximum concentration between horses, ranging from 2.11 to 6.20 ng/ml. However in all the horses the pergolide was absorbed quickly, with time to maximum concentration ranging from 0.33 to 1 hour. These results suggest that, as in humans, the metabolism/elimination profile of pergolide varies considerably between treated horses. 

Pharmacokinetics of pergolide in normal mares
Abra Wright MSc thesis 2009

Rendle concluded that pergolide does not require a loading dose. However giving pergolide twice daily may be more appropriate than once daily.

If this is the case, and the dose currently given once daily would be more effective if split into two doses, surely Prascend tablets need to be capable of being divided into quarters rather than just halves? Or is the suggestion that the daily amount of pergolide split into two doses would be larger than the dose currently given once daily? Good news for Boehringer Ingelheim (by whom David Rendle acts as a paid speaker and consultant) if this research supports giving a larger overall dose!

Both researchers used much larger doses of pergolide than are normally used, the research was carried out on healthy horses, not horses with PPID, only a single dose of pergolide was given in each case, and in both cases the pergolide was not administered in the same way as owners give pergolide - in Rendle's research the dose of pergolide was given intravenously, in Wright's research although the pergolide was given by mouth, it followed an 8 hour fast. So just how relevant is this research in terms of recommending oral dosing of pergolide for horses with PPID?

If you are claiming on your horse insurance for laminitis treatment, it's worth asking whether your policy covers the purchase of hoof boots - we've been told that one insurance company (Petplan Equine) has paid almost the full price of a set of 4 hoof boots. And so they should - if they cover remedial shoeing, they should also cover hoof boots and pads for remedial use.