....."If a horse is diagnosed and being treated for PPID, do you still have to be extra careful regarding their access to pasture?".....
>>> you are talking about two different disease processes here -- PPID (aka Cushings) is the disease of older horses that causes the long coat, excessive drinking, etc. Insulin resistance (IR) is a metabolic condition affecting horses of any age, that can arise *with* PPID or *separately*. This is the condition where insulin is elevated due to intolerance to certain sugars in the horses diet (grain, grass, etc). Elevated insulin that is not diagnosed and controlled will often lead to laminitis. Some PPID horses also have IR and their IR is driven so to speak by the PPID disease. For example:
I have two horses:
21yo mare who is PPID and severely IR. She cannot eat grass, grain, fats, etc. Her high-normal leptin test results repeatedly show that her IR is caused by her PPID Once she started perglide, her IR was much easier to control. Will lives in a drylot for rest of her life. Her PPID and IR are controlled by daily pergolide (Prascend), & strict, balanced diet of 15lbs ODTB hay cubes (made for IR horses), and small amt soaked grass hay.
8yo gelding who is severely IR. His ACTH is not elevated nor does he have signs of PPID. His extremely elevated leptin tests repeatedly show that his IR is a primary pathology, not a secondary one caused by PPID (unlike my mare's IR). This gelding also cannot eat grass, grain, fats, etc. Also will likely live in a drylot for life. His IR is very easily controlled by strict adherence to a balanced diet -- the hay cubes made for IRs, and sm amt soaked grass hay. He does not need pergolide bc he does not have PPID. Although my gelding is only 8 and shows absolutely no signs of PPID, I still test him b/c I want to establish a baseline ACTH # for if/when he may show signs of PPID as he ages.
....." He has only had insulin test before, which was negative......"
>>> This is confusing b/c insulin test results are always listed as a number. Different labs use different criteria as "normals". This group, based on years of anecdotal experiences, utilizes a different set of "normal" numbers altogether. So when you say your horse was "negative" doesn't make much sense! Insulin can, and does, fluctuate constantly -- my super sensitive IR mare can be in and out of an insulin crisis in 2-3 days if I catch it immediately and fix whatever has spiked the insulin. I test her insulin at least once a month (I own my own hospital) and its all over the place, so rigid, ongoing, virtually constant observation of her symptoms (lethargy, depression, foot tenderness, "hiding", crankiness, thickened front legs, sudden increase in drinking/urinating, hardened crest, stumbling, etc) is what I rely on to prompt a test to the lab. My point is that one insulin test doesn't rule out Insulin Resistance for life -- its a dynamic but insidious syndrome based on metabolic fluctuations, hormones, etc. The other two tests for diagnosing IR are glucose and leptin. The ACTH is for diagnosing PPID.
hope this helps a bit differentiating betw PPID and IR and what tests are nec for each,
Kerry in NY