Meet Bliss AKA: Mielies

AND LEARN MORE ABOUT CUSHING'S DISEASE

Debbie Stevenson, from Blue Horizon’s Riding School, Drummond, KZN, shares Bliss' story with us.

"Bliss is 25 years old now. During his exciting life, he has taken part in more than six international test series in PoloX. But that is not where the story is…

My sweet boy, who came home to us as a 5-yearold, was diagnosed with Cushing's Disease a year ago… and it has progressed unbelievably rapidly. My heart is handling it, but he is my daughter's pony, and she lives in Australia. Watching him decline has been extremely difficult. This winter was the worst ever, and he lost so much weight. But he is now on the up, and I'm hoping he will have a good summer."

Lots of horses and ponies are affected by Cushing's Disease. Here, we learn more about the condition so you can spot the signs early.

What is Cushing's Disease?

Also known as pituitary pars intermedia dysfunction (PPID), Cushing's Disease is the most common endocrine disorder diagnosed in horses and ponies. Endocrine disorders are those that affect the production of hormones in the body.

Although Cushing's Disease in horses carries the same name as a similar condition that affects people and dogs, the disease process is different in horses.

All breeds can be diagnosed with Cushing's Disease, but ponies and Morgan breeds seem to be more likely to develop Cushing's Disease than others.

Symptoms of Cushing's Disease

Cushing's Disease is a progressive condition, meaning it gets worse over time. The symptoms may be slow to present but will progress with time.

The most common signs observed in horses and ponies with Cushing's Disease/PPID include:

• Failure to shed their winter coat fully or patchy shedding

• A long and/or curly coat

• Chronic infections

• Laminitis or multiple laminitis episodes

• Hoof abscesses

• Excessive or inappropriate sweating

• Increased water intake and urination

• Lethargy

• Weight loss

• Accumulation of fat in abnormal areas

• Loss of muscle mass (especially over the back and hindquarters)

• A pot-bellied appearance

• Infertility in mares

• Suspensory ligament (ligaments in the leg) degeneration

• Recurrent corneal (eye) ulcers

Causes of Cushing's Disease

In a healthy horse or pony, the endocrine system is a balanced group of structures and organs that work together in feedback loops to produce and control hormone levels throughout the body.

In horses or ponies with Cushing's Disease, the normal mechanisms that control hormone production by the pituitary gland are damaged. This means that too much hormone is produced. These hormones then enter the circulatory system and affect the whole body.

How vets diagnose Cushing's Disease

The vet diagnoses PPID by listening to your horse's medical history, performing a physical examination, and doing a diagnostic test. There are two main diagnostic tests for PPID: a baseline plasma ACTH concentration and a thyrotropin-releasing hormone (TRH) stimulation test (don't worry about the names!)

Treatment of Cushing's Disease

The first-line treatment for Cushing's Disease is a tablet called pergolide. Some horses and ponies may need to be started on pergolide gradually as it can cause a decrease in appetite. Routine blood monitoring is advised for horses on pergolide to make sure that the treatment is effective and helping them.

Chat to your vet

If any of these symptoms sound familiar, and you are concerned your pony may be showing signs of Cushing’s Disease, chat to your vet.