PPID in older horses – is it actually normal?

curable disease but in many cases it can be managed
From a medical point of view cases are usually treated with a dopamine receptor activator agonist known as pergolide. This drug can slow down the enlargement of the pituitary gland. Some horses will respond quite well to this treatment as evidenced by lower levels of circulating ACTH and a reduction in the severity of clinical signs. Horses on treatment will need to be monitored to ensure effective dosage which is why it is useful to confirm the diagnosis with a blood test even if clinical signs are very obvious. If we know the pretreatment levels of ACTH we can monitor the response more easily. The level of ACTH does not predict the severity of the disease but it can be used to check the response. In general vets recommend retesting 6 weeks after starting treatment and every 612 months afterwards unless the condition worsens. 
As we know these animals are at risk of laminitis we also need to address their management in terms of dietary restriction and pasture access. To assess the risk of laminitis we often consider the clinical signs history and insulin levels as well as response to medication.
In addition to dietary management we should also ensure that we monitor other clinical signs
For example if the horse has hypertrichosis they should be clipped and groomed to ensure comfort and good skin health. These horses can be more susceptible to infections. So a close eye should be kept on their overall health including routine vaccinations faecal worm egg counts tapeworm testing and dental care to reduce the risk of problems developing. 
What if the horse has no clinical signs associated with PPID? 
Owners often ask if we should treat asymptomatic cases who seem otherwise fit and well. ACTH levels are very accurate in identifying cases of PPID ie if the horse has a high ACTH it is very likely that the horse has PPID. However we should look at the overall health of the horse. If they have PPID it is likely that they will develop clinical signs over time and when that happens is difficult to predict. Given the high incidence of laminitis in cases of PPID one could argue that we should be treating all cases. 
It is likely although yet not fully proven that early treatment with pergolide may slow the progression of the disease. But the