Cushing’s Disease VS Metabolic Syndrome
By: AAEP
Is your horse 15 or older? Read on!
With each passing year, horses are living longer lives and many survive easily to 25 years of age or older. While this is good news, it also means that horse owners need to be aware of changes occurring with age, so they can preserve the health and quality of life of their equine friends throughout middle age and the geriatric years.
For example, Equine Cushing’s disease is one of the most common diseases of horses greater than 15 years of age. This syndrome is better defined as Equine Pituitary Pars Intermedia Dysfunction (PPID) because it reflects the location within the brain that’s abnormal, and the clinical signs are associated with abnormally elevated hormone concentrations in the blood.
Equine Metabolic Syndrome (EMS) is another endocrine disorder that can affect mature horses and shares some of the same clinical signs as PPID. Although the two disorders feature some striking clinical similarities — most notably a predisposition to development of chronic laminitis — the underlying disease biology is quite different in each case and successful management requires proper diagnosis by a competent veterinarian first.
Our understanding of both conditions, especially EMS, is incomplete and subject to continuous evolution, but sufficient information is currently available to highlight some important similarities and differences for the interested horse owner. Consult your veterinarian for more information and work with them to develop the best wellness practices to ensure a healthy life for your mature horse.
Additional information regarding the older horse’s care and nutrition is available on our website.
Equine Cushing’s disease
- A disorder of the pituitary gland that results in hormonal imbalances. The disease tends to occur in middle-aged and geriatric horses.
Clinical Signs:
- A long, wavy hair coat that fails to shed according to normal seasonal patterns
- Excessive sweating
- lethargy and poor athletic performance
- chronic recurrent laminitis
- infertility
- weight loss and muscle wasting
- abnormal distribution of fat
- consumption of large volumes of water and passage of large amounts of urine
- delayed wound healing and increased susceptibility to injections
What Causes It:
The intermediate part (pars intermedia) of the pituitary gland produces excessive amounts of pro-opiomelanocortin (POMC) and several hormonally-active derivatives, including adrenocorticotropic hormone.
Equine Metabolic Syndrome
- A cluster of conditions affecting somewhat younger adult horses including obesity, insulin resistance, hyperglycemia, and chronic laminitis.
Clinical Signs:
- Obesity
- Insulin resistance and hyperglycemia
- Chronic laminitis
A long hair coat is NOT a feature of the condition and tests of the pituitary function usually yield normal results. Furthermore, affected horses do not respond to medications which are frequently of benefit in cases of Cushing’s Disease.
What Causes It:
Obesity appears to be the central problem in horses (and humans) suffering from metabolic syndrome.
Although the two disorders feature some striking clinical similarities- most notably a predisposition to development of chronic laminitis- the underlying disease biology is quite different in each case and successful management requires a proper diagnosis first. Consult your veterinarian to learn more.
(Provided with permission by AAEP)
