What is ACTH?
 

ACTH - Adrenocorticotrophic Hormone: A hormone produced by the pituitary gland that triggers production of cortisol from the adrenal gland.  Also the name of the single draw blood test (endogenous ACTH) used to diagnose Cushing’s disease.

What is Chastetree Berry?

CTB, Chastetree Berry (Vitex agnus-castus): An herb with some of the same effects as the drug pergolide and which may control equine Cushing's disease symptoms in some horses. Most horses will need to be placed on the drug pergolide for effective control.

What is Cortisol?

Cortisol: A hormone produced by the adrenal gland that is released naturally during times of stress (e.g. excitement, transport, exercise, infections, trauma, pain, fear). When production is abnormally high and sustained, it can result in impaired immune function, resistance to insulin, electrolyte abnormalities and impaired ability to utilize protein in the diet.

What is Cushing's Disease?

Cushingʼs Disease is a disorder of the pituitary gland and results in hormonal disturbances. The pituitary gland secretes high levels of the hormone ACTH which stimulates the production of cortisol, a stress hormone. This is generally considered a disease of middle-aged or geriatric equines.

What is DDT/E?

DDT (DDT/E): Acronym for Diagnosis, Diet, Trim and Exercise – all must be addressed together for a successful recovery/rehabilitation.

What is Dexamethasone Suppression Test (DST)?

Dexamethasone Suppression Test: measures cortisol response to a dexamethasone challenge. While considered the “gold standard” by some veterinarians, it may pose a risk of precipitating or exacerbating laminitis.  More and more professionals are turning to the Endogenous ACTH test for diagnosis of Cushing's Disease/PPID.

What is the Emergency Diet?

The temporary “Emergency Diet” was developed to address the IR horse’s immediate needs for adequate gut fill, appropriate energy levels to support requirements, and to improve insulin sensitivity.  Meant for initial short-term use only, a mineral balanced low sugar/starch diet should be implemented as soon as possible.  A copy of the Emergency Diet here!

How important is Exercise?

The Importance of Exercise – Exercise vastly improves insulin sensitivity but, obviously, the acutely laminitic horse cannot tolerate exercise. However, with recovery, exercise is to be encouraged as long as the horse tolerates it. Even hand walking, 30 minutes per day (straight lines, no tight turns) is beneficial. As the horseʼs condition improves, the level of exercise should increase. The importance of exercise in the IR prone horse cannot be understated. IR can be avoided completely with adequate exercise and diet management.

How much should I Feed my horse?

ALL horses, regardless of diagnosis, need to be fed 1.5-2.0% of body weight.

1000 lb horse x 1.5% = 15 lbs of feed per day  OR  1000 lb horse x 2.0% = 20 lbs per day

For horses that need to lose weight, feed 1.5% of the horse's current body weight or 2.0% of the horse's ideal body weight - whichever is MORE!   Starvation” diets to address obesity by providing small amounts of “poor” quality hay have been universally unsuccessful for the IR horse and will actually worsen Insulin Resistance!

What is the G:I Ratio?

Glucose to Insulin Ratio (G:I ratio):  The glucose:insulin (GI) ratio is basically a very simple concept. This ratio/number indicates how many “units” of insulin are being secreted per “unit” of glucose. The smaller the number, the less sensitive the cells are to insulin. For example, a normal horse may have a blood sugar of 100 and an insulin of 10, for a GI ratio of 100/10 = 10, while an insulin resistant horse with a blood sugar may have an insulin of 25 for that same blood sugar of 100, yielding a GI ratio of 100/25 = 4. Both insulins may be within the laboratory's “normal range”, but those normals represent a variety of diets and various times after eating. Obviously the horse that has a circulating insulin level 250% higher than another horse with the same blood sugar level is less sensitive to insulin.  A ratio <4.5 is diagnostic for Insulin Resistance, while a ratio between 4.5 and 10 represents compensated IR.

IR Calculator is the tool designed to calculate the G:I Ratio, RISQI and MIRG.

What is Insulin Resistance?

Insulin Resistance (IR) is a condition where cells do not respond to insulin, the hormone primarily responsible for transporting glucose into the cells. It is sometimes also referred to as “Equine Metabolic Syndrome” or by the terms “Pre-Cushings” or “Cushingoid” which further complicates obtaining a correct diagnosis. While IR often occurs in the horse with PPID, it is a distinctly separate condition from Cushingʼs disease and it can occur without Cushingʼs.

What is the difference between Laminitis and Founder?

Laminitis: Inflammation of the laminae – the tissues that connect the coffin bone to the hoof wall inside the foot. Often, the first sign of Cushing’s or IR is laminitis.

Founder: Often used synonymously with laminitis. Most people use the term founder to indicate horses whose coffin bone has come loose from its hoof wall attachments and is displaced. (See laminitis, rotation and sinker.)

What is MIRG?

Horses that have elevated blood glucose, or abnormally low insulin responses, may have RISQI and G:I results that are normal because they have actually crossed the line from insulin resistance to actual diabetes.

MIRG = modified insulin:glucose ratio. It is calculated by: [800 – 0.3 x (insulin – 50)2] /(glucose – 30)]. If G:I ratio or RISQI are positive, there is no need to do this calculation, but if the horse has symptoms of IR and those equations are normal, you should check the MIRG, especially if blood glucose is elevated.

IR Calculator is the tool designed to calculate the G:I Ratio, RISQI and MIRG.

What is Pergolide?

Pergolide (pergolide mesylate): A dopamine agonist medication, available by veterinarian prescription and dispensed by a compounding pharmacy; pergolide is considered the gold standard of treatment to control the symptoms of equine Cushing's disease.

What is PPID?

Pituitary Pars Intermedia Dysfunction (PPID):  In the horse, what is commonly called Cushing's Disease is caused by hyperplasia (enlargement) or adenoma (benign tumor) in a portion of the pituitary called the pars intermedia (intermediate lobe).

What is RISQI?

RISQI: A proxy developed by researchers at Virginia Polytechnic Institute. RISQI stands for “reciprocal of the square root of insulin” and is calculated by the equation 1/square root of insulin. A RISQI value of 0.2 to 0.32 represents compensated insulin resistance while a value of less than 0.2 indicates failed compensation (high risk of laminitis).

IR Calculator is the tool designed to calculate the G:I Ratio, RISQI and MIRG.

What is the Seasonal Rise?

Seasonal Rise is a term used to describe the fluctuations in ACTH in older horses, generally during the months of August to November.  These fluctuations become exaggerated in horses with PPID and may in fact increase the risk of laminitis in horses with early PPID.  Seasonal Rise may also influence Insulin and Glucose tests.  More information here:  SEASONAL RISE

Should I Test my horse during the Seasonal Rise?

Testing during Seasonal Rise as a conclusive first diagnosis of PPID won't be accurate unless also accompanied by a constellation of other PPID symptoms.  To be considered "full blown" PPID, the horse will test positive all year round.  Testing horses experiencing late summer/fall laminitis (not diet induced) is recommended since these horses may benefit from seasonal low doses of Pergolide.  Testing during Seasonal Rise can also help owners and veterinarians of confirmed PPID horses adjust medication doses.   More information here:  SEASONAL RISE

What is Vitex?

Vitex: see Chastetree Berry. Sold under the brand name “Evitex” (formerly Hormonise) in the US, available as “Hormonise” in the UK.  This is the liquid extracted from Chastetree Berries.