Did you know that dressage horses are especially predisposed to developing Cushing’s disease?
Well, according to an eminent veterinary surgeon from Wisconsin, U.S., that’s the case. It’s thought that dressage horses are particularly susceptible to suffering from Cushing’s because they are usually ‘easy keepers’.
So, what is Cushing’s disease, and how can you manage the condition?
What is Cushing’s disease?
Cushing’s disease is caused by problems within the pituitary gland, a small structure that is found at the base of the horse’s brain.
The pituitary gland controls the adrenal gland’s production of natural steroids, including cortisol.
In horses with Cushing’s, the function of the pituitary gland is disrupted due to enlargement or because of a benign tumor within the tissues.
Horses that are affected by Cushing’s disease can produce reduced amounts of the neurotransmitter, dopamine. That imbalance causes an increase in cortisol, and that is what causes most of the problems that are associated with Cushing’s.
What are the symptoms of Cushing’s disease?
Cushing’s disease is most commonly seen in horses aged 15 years and above. Most cases are seen in aged animals in their early 20s or 30s. Male and female horses are affected with equal frequency.
The classic signs of Cushing’s disease include:
- A long, curly coat that doesn’t shed
- Loss of weight, even though the horse’s appetite remains good
- Muscle wastage over the quarters
- A pot-bellied appearance
- Accumulation of fatty deposits along the crest, above the root of the tail, and behind the eyes
- Increased sweating, even in cold weather
- Excessive urination and drinking
As the horse’s immune system becomes suppressed, wound healing may be slow and problematic, and recurrent infections are common.
Foot abscesses and laminitis affect around half of all horses with Cushing’s disease, although there is no apparent cause for this.
Many early-stage Cushing’s horses develop sore feet immediately after shoeing or trimming.
Diagnosis and treatment
The diagnosis of Cushing’s disease is usually via a blood test, although the assessment of clinical signs is often a primary indicator of the condition.
Drug therapy can help to alleviate some of the clinical signs of Cushing’s. Many horses respond well to pergolide (Prascend), primarily when the drug is used in conjunction with another popular medication, cyproheptadine.
Unfortunately, pergolide is on the FEI’s list of prohibited substances, so horses on this drug cannot compete.
Also, you may find that your horse’s energy levels are lower than usual while he is taking pergolide, and muscular stiffness can also be a problem.
Managing Cushing’s disease
Cushing’s disease cannot be cured, although there are steps that you can take to manage the condition.
If the horse has a thick coat, clipping will be beneficial, especially in warm weather.
Excellent dental care is vital to make sure that the horse can make the best use of his diet.
Healthy dentition can also help to prevent oral infections.
You should seek the advice of a professional equine nutritionist to ensure that your horse’s diet is balanced correctly to provide maximum nutrition and weight maintenance while minimizing the risk of laminitis.
Monitor the horse’s weight regularly with a weigh-tape to make sure that any necessary dietary adjustments can be made promptly.
It’s essential that you have your farrier check your horse’s feet regularly to help prevent problems such as laminitis and abscesses.
To offset the horse’s compromised immune system, all infections must be treated immediately.
The horse must be wormed regularly, and his vaccinations should be kept up-to-date.
Cushing’s horses with long, thick coats that live out can be prone to picking up lice infestations.
Be sure to check your horse’s coat regularly for the presence of lice, and treat the parasites accordingly.
Preventing Cushing’s disease
The most important thing you can do to reduce your dressage horse’s risk of developing Cushing’s is to keep his weight down by providing proper nutrition.
That means feeding your horse only what he needs. Avoid feeding sugary treats and too many carrots and apples.
Also, it’s a good idea to restrict your horse’s grass intake by fitting him with a grazing muzzle, especially during the spring and fall when the sugar levels in grass are at their highest.
A low-sugar feeding regimen is essential to prevent the onset of laminitis.
Be vigilant for the symptoms of Cushing’s, and if you suspect that something is amiss, contact your vet immediately.
Horses with Cushing’s cannot be cured of the condition, but it can be managed via drug therapy. However, you must check that the drugs your horse is taking are legal for competition under FEI rules.
Does your dressage horse have Cushing’s? We’d love to hear your story! Share with us in the comments section below.