What is the Equine Cushing’s or PPID?
The term horse Cushing’s is also called hypothalamic or pituitary pars intermedia dysfunction (PPID). The most common symptoms include weight gain, depression, and a poor feed to work ratio.
People frequently mistake generalized obesity as Cushing’s when it is actually carried too close to the skin. These horses can have thin extremities and muscle wasting. The most common sign of the weight gain is the belly being larger than the shoulders.
Eating excessive amounts of forage and not getting enough exercise is a common cause of obesity in horses. In turn, this is one of the contributing factors for PPID, as the body’s attempt to bring its hormone levels back into balance causes the body to stop making cortisol, the natural form of the steroid hormone cortisol, and produces an overabundance of the precursor hormone pituitary growth hormone.
Cushing or PPID Affects Horse Quality Life
Cushing’s syndrome (Cushing’s disease) and pituitary pars intermedia dysfunction (PPID) are similar syndromes in terms of clinical signs, pathophysiology, and pharmacological management.
Affected horses remain sound and functional for the most part, and a rapid decline in health is uncommon.
Clinical signs include progressive and hyperkinetic behavior, causing hyperactivity and even aggression. Clinical signs can be diffuse, leading to a general change in attitude, locomotion, and demeanor.
Horses also respond to stress in a different manner, a change in attitude, and different balance with the challenge of being a herd species. This can result in unusual behaviors for the horse such as stumbling, lurching, and seeming as if it is off balance.
Is it Diagnosis and Treatment Effective-Feasible?
Due to the pituitary gland’s hormone producing function, the hormone profile results of the hypothalamus/pituitary/adrenal axis can become deranged and can interfere with the normal expression of the horse’s endocrine function. It’s a problem that can interfere with the horse’s lead-up condition for planned events and in some cases, may effect the results of diagnostic testing. This is considered a challenging question and as such, avoiding it completely is not possible. To be fair to the horse, the best thing to do is to have the challenge properly diagnosed and then make a decision after full consideration. If the horse is otherwise in good health, symptom-free, and the owner is serious about owning the horse for a long time then a reasonable approach is to manage the condition.
For horses that won’t be able to continue to perform to a high level, the treatment plan should minimize the adverse effects that are seen with this disease. These can include:
- Adverse effects of mineralocorticoids on bone and muscle and anemia
- Adverse effects of growth hormone on muscle, bone, and the liver
- Excessive appetite, weight gain, increased thirst
- Behavior changes, flipping and biting
Finally, When To Euthanize A Horse With Cushing’s?
Although some of the signs you would see in Cushing's horses, similar to older horses, can be unavoidable, if a younger horse is sick, it is time to consider euthanasia.
Because you're dealing with Cushing's, this is especially true if the horse isn't eating, sleeping, getting up when it should, and doesn't have the same spirit as before. In these circumstances, euthanasia is the humane thing to do.
Cushing's disease in horses is particularly difficult to diagnose, and many times, the disease is only discovered once the horse is in its final stages.
It's even more difficult to assess the pain that the horse is in, or if the horse's euthanasia is warranted. If you are considering euthanasia, please make sure you talk to your vet about the possibilities and the pros and cons of the process.
Don't try to make a decision on your own, make sure your vet is there to walk you through the rest of your horse's health.
Euthanizing a horse in this state is no easy task. If you are interested in euthanizing the horse, it would be best to set a date to euthanize your horse and make plans for the final moments of the horse's life.
Talk to your veterinarian about what is allowed in your state.