What is PPID and how is it treated in horses?

Importantly, equines with PPID will often have laminitis

Recent evidence has shown that in PPID there is often a long phase where laminitis is present but not causing a problem to the horse, although it may be suspected from divergent lines on the hooves. As it is the one sign of PPID that can have a serious impact on the horse or pony’s quality of life it’s important to look out for early warning signs of laminitis. Laminitis is a whole other topic in itself, but the laminitis seen with PPID and equine metabolic syndrome (EMS) is a bit different to that seen with pasture or stress related induced laminitis. Catching PPID before bouts of painful laminitis occur can help prevent the often chronic relentless cycles of laminitis that can occur from other causes.

If you see the signs of PPID then it’s a good idea to get your vet out to do a check up, or it may be that they recommend testing for the disease at a routine check or dental appointment based on your horse’s appearance or history.

Testing for PPID

The first line of testing is often an ACTH (adrenocorticotrophin hormone) test through a blood sample. This may be done with or without a full haematology and biochemistry panel to check your horse’s general state of health. ACTH is one of the hormones secreted by the pituitary gland. In PPID horses and ponies, it is present at blood concentrations higher than normal because of the dysregulated activity of the gland.

However, as mentioned the disease is gradual in onset so sometimes horses that have early PPID won’t have levels above normal. Either repeat testing in the future, or additional tests are needed to confirm the disease. This is also an important topic of current research. 

How is PPID treated?

The mainstay of treatment is a drug called pergolide which is given by mouth each day. Often a higher dose is given initially to control the signs, which can take several months. Sometimes it can be reduced, but lifelong treatment will be needed. Good management of horses and ponies with PPID includes clipping the excess hair to prevent sweating and daily grooming to keep the horse clean. Gentle regular exercise is also beneficial in those that do not show signs of laminitis. 

If the horse already presents with signs of laminitis this will require appropriate control depending on the degree. This often means remedial