Is your horse overly hairy, looking a bit pot-bellied or just not their normal self?
If the answer is yes to any of these questions, particularly the recurring laminitis one, and your horse is over 15 years of age, we’d suggest you give us a call so that we can investigate whether Cushing’s Disease (also known as Pituitary Pars Intermedia Dysfunction or “PPID”) may be to blame.
While many cases of laminitis have previously been thought to have been caused by nutritional issues, there is now a growing body of evidence that suggests that up to 80% of laminitis cases seen in practices like our own could be the result of a hormonal imbalance such as Cushing’s Disease – which is why we’re starting to talk about it. A simple blood test could be all that is needed to diagnose Cushing’s.
So what is Cushing’s Disease?
Equine Cushing’s Disease is the most common hormonal disorder of older horses and ponies. We understand that over 15% of horses and ponies over 15 years of age are affected. Combine this with the fact that over 80% of horses suffering from laminitis may have an underlying endocrine disorder like Cushing’s Disease, and it is clear why all of a sudden there is an increasing level of interest in the condition. While the condition is more common in older horses and ponies, many still enjoying active lifestyles can be affected.
What causes Cushing’s?
The pituitary gland controls a range of important functions including metabolism, reproduction, growth and lactation. As your horse ages, nerves in part of the brain called the hypothalamus undergo progressive degeneration, and produce insufficient quantities of a nerve transmitter called dopamine. Dopamine normally inhibits the production of some hormones from the neighbouring pituitary, so if there is inadequate dopamine production, these hormones tend to be produced in excessive quantities, resulting in the clinical signs associated with Cushing’s.
So what are the clinical signs?
We’ve already mentioned laminitis and hirsutism (abnormal coat), which are two of the most common clinical signs of Cushing’s. But there are plenty of others, which are often variable and not necessarily specific to Cushing’s, and these include:
- excessive sweating
- increased appetite
- increased drinking and urination
- poor performance
- reduced immune function leading to reoccurring skin and respiratory infections, dental disease and an increased susceptibility to worms.
- loss of muscle and a pot-belly
- abnormal deposit of fat around the eye
As with most conditions, early diagnosis and treatment of horses and ponies affected by Cushing’s Disease delivers the best outcome. If you recognise any of the signs, we can carry out a blood test to confirm whether or not Cushing’s is the cause.
Treatment and management
Treatment of horses with Cushing’s centres on dealing with any immediate medical problems (eg: laminitis cases generally require a combination of pain relief, foot care etc), and then addressing the underlying hormone imbalance.
There is no cure for equine Cushing’s Disease, but there is an effective licensed medicine which helps get the hormone secretions back in balance. This helps to reduce the clinical signs associated with the disease – such as any laminitis.