As a horse advances in years he can begin to suffer from Equine Cushing’s disease. Emma Seamark, a vet in the equine technical team at Boehringer Ingelheim Animal Health, reveals how to spot the tell-tale signs and advises on the management strategies that can keep a horse with Cushing’s happy and healthy.

Signs of the times

There are a multitude of clinical signs associated with Equine Cushing’s disease, and the combination of signs will vary from one horse or pony to another. It’s important to be aware of all of the clinical signs of the disease as early ones are often overlooked, or can be mistaken for normal signs of ageing, which can delay diagnosis and treatment. Other signs may develop over time as the disease progresses.

Key signs include:

  • Laminitis — The signs of laminitis can vary from mild changes in the hooves through to severe lameness. Horses with Equine Cushing’s disease are at an increased risk of developing laminitis compared to older horses without the disease.
  • Muscle wastage — This is usually seen as a loss of topline over the back.
  • Abnormal fat deposits — Fat can develop in abnormal places. This is usually seen as a pot belly and ‘fat pads’ over and/or around the eyes.
  • Abnormal sweating — Patchy or abnormal sweating patterns, or unusually high levels of sweating after low levels of exercise in cool temperatures, may occur.
  • Recurrent infections — Horses with Equine Cushing’s disease are more susceptible to infection. These may be seen as signs of infection that don’t respond to treatment as expected, such as an infection that keeps coming back, or a high worm burden.
  • Lethargy — Typical signs of lethargy may be that your horse appears less interested in exercise or his surroundings, or he may not be interacting with you as he normally would. Lethargy can sometimes be difficult to spot as the onset is often gradual and may sometimes be mistaken for a horse getting older.
  • Increased thirst and urination — This is not always easy to spot, but it may be seen as a sudden change in the amount of bedding that is required to keep the stable dry, or a change in how frequently you need to fill the water trough/bucket.
  • Abnormal hair coat — Early disease is frequently associated with delayed moulting and patches of long hair, whereas advanced disease usually causes a more generalised hair coat and complete loss of the seasonal moulting pattern.
  • Reduced fertility — Mares with Equine Cushing’s disease may have diminished fertility, and so their ability to get in foal may be reduced.

Diagnosis and treatment

The ACTH test is the simplest and most common test for Equine Cushing’s disease. A vet will take a blood sample from your horse, if appropriate, and send it to a laboratory to measure the levels of the hormone ACTH. High levels will indicate that your horse has Equine Cushing’s disease.

Once a horse has been diagnosed with Equine Cushing’s disease there are many management strategies that can be implemented to ensure that he remains happy and healthy.

1. Medical treatment 

If appropriate, your vet may prescribe life-long medication to treat the clinical signs associated with Equine Cushing’s disease.

2. Nutrition

Correct nutritional support can help a horse or pony cope better with the consequences of Equine Cushing’s disease, such as muscle wastage. In most cases lifelong medication is needed to alleviate the symptoms of Equine Cushing’s disease.

Some horses with the disease may also show clinical signs, such as weight loss, obesity, or a predisposition to laminitis, which means they will require an individual nutrition plan.

3. Preventative care

In addition to Equine Cushing’s disease, there are a wide range of common diseases that horses and ponies are at risk of developing as they get older, such as dental and musculoskeletal disorders.

Preventative healthcare is important for all older horses, but especially for those with Equine Cushing’s disease, so always ensure you pay special attention to hoof care, dental care, vaccination, wormer administration and nutrition.

4. Exercise

Many horses with Equine Cushing’s disease are able to continue their athletic careers, and exercise is always helpful for their metabolism. If your horse is sound, then keep up his regular exercise.

If he is less athletic but sound then you can try to ride, long-rein, or lead him out at a brisk walk regularly. If you are unsure whether it is suitable to exercise your horse then seek advice from your vet.

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