Equine PPID Flashcards
describe the pathophysiology of PPID in horses
in the normal physiology: POMC is converted into ACTH and other production by melanotropes, the anterior pituitary (pars intermedia) and dopamine is responsible to inhibiting this breakdown
PPID: degeneration of dopaminergic neurons prevent inhibition of this mechanism, causing overproduction of ACTH and other stuff and hypertrophy of the melanocytes leading to pituitary enlargement
Common signalment for PPID
older horses (18-23 yrs)
Clinical signs of PPID
- Hirsuitism/hypertrichosis: long curly coat - 100% of horses with this have PPID
- weight loss with good appetite
- regional adiposity
- muscle atrophy due to excess cortisol/protein catabolism
- laminitis or recurrent sole abscesses (due to high cortisol +/- hyperinsulinemia)
- abnormal sweating (increased or decreased)
- Chronic infections
lab findings common with PPID
- hyperglycemia
- hyperinsulinemia
- hypertriglyceridemia
- high fecal egg count
what diagnostic test can be used to dx PPID?
- Basal ACTH
- TRH stimulation (breaks down POMC)
interpreting basal ACTH Testing
- dependent on time of the year
- horses well above the reference range have PPID
- horses in the equivocal grey zone may not- older horses with compatible clinical signs are likely to have PPID, young horses with few or no clinical signs do not
Interpreting TRH Stim Test
- baseline ACTH and post- TRH admin ACTH levels measured
- dependent on time of year
- horses well above the reference range have PPID - - horses in the equivocal grey zone may not- older horses with compatible clinical signs are likely to have PPID, young horses with few or no clinical signs do not
Treating PPID
- daily admin of dopamine agonist (pergolide)
- recheck ACTH in 30 days
Managing PPID
frequent dental care
regular parasite tx
appropriate farrier care to prevent laminitis
weight loss
clip hair in summer
