What is PPID and how is it treated in horses?

PPID stands for Pars Pituitary Intermedia Dysfunction. It is the correct veterinary term for what is commonly referred to as equine Cushings disease. Over the last few decades our understanding of PPID has progressed substantially. However there are still aspects that we have yet to fully understand. Ongoing worldwide research on the topic is trying to fill in the gaps so that we can diagnose PPID earlier and manage it more effectively.
Table of contents
What happens in PPID?How do I know if my horse or pony has PPID? Importantly equines with PPID will often have laminitisTesting for PPIDHow is PPID treated?What does PPID mean for my horse?

What happens in PPID?
Time for a bit of biology! The brain is a complex structure with many working parts which all have to communicate with each other correctly in order for the body to function as it should. There is a region called the hypothalamus which can be thought of as a control centre. The hypothalamus regulates many essential processes including endocrine hormone function it sends signals to its neighbour the pituitary gland which then releases the hormones that set in motion these pathways.
The hypothalamus also has nerves that connect it to the pituitary gland. These nerves release a substance called dopamine which acts to prevent the pituitary gland from being overactive. Basically they keep the gland in check. 
In horses that have PPID these nerves are damaged meaning that the pituitary gland isnt inhibited by dopamine. Its a gradual process thought to be caused by agerelated damage to the nerves which leads to overactivity of the pituitary gland and excess production of the hormones it secretes.
How do I know if my horse or pony has PPID? 
As mentioned PPID is believed to be brought about by agerelated change. This is why its commonly seen in older or geriatric horses generally above 15 years. Many horse owners are aware of the typical curlycoated appearance of affected horses and its a good sign to look out for. Whats actually going on is that abnormal pituitary gland function causes dysregulation loss of control of the normal seasonal hair growth patterns as a result the hairs are being held on to instead of being shed appropriately. 
The disease can also cause subtle signs such as weight gain or fat accumulation often appreciated as a cresty neck and muscle weakness which can create a potbellied appearance. Many horses will