Pituitary Pars Intermedia Dysfunction Flashcards
Describe the pathophysiology of PPID in horses
It’s a slowly progressive age related degenerative disease of hypothalamic dopaminergic neurons in the hypothalamus. Dopamine breaks down POMCs in the pars intermedia of the hypothalamus. This process if usually under inhibition but with PPID we lose the inhibition so we get overproduction of POMC and its products such as ACTH
list some clinical signs of PPID?
- hypertrichosis
- delayed shedding/hair coat changes
- muscle wasting
- laminitis
- lethargy
- abnormal sweating
- PU/PD
- tendon/ligament laxity
- regional adiposity
- recurrent infections/delayed healing
- infertility/abnormal lactation
What diagnostic tests are available for PPID?
TRH Stimulation Test and Baseline ACTH Test
Younger horses with few, mild or early clinical signs should be tested by the __ while older horses with many, severe or more advanced clinical signs should be tested by the __
Younger horses with few, mild or early clinical signs should be tested by the TRH Stimulation test while older horses with many, severe or more advanced clinical signs should be tested by the Baseline ACTH test
T/F: if TRH stimulation testing is not feasible, baseline ACTH alone can be used for diagnosis, but may be less supportive of diagnosis in the earlier stages of the disease
T
T/F: Many healthy animals have variably exaggerated ACTH responses to TRH in the autumn
T
what months is TRH stimulation the most useful to ID negative cases?
July - December
What is the treatment of PPID?
Prascend (pergolide tablets) then evaluate clinical signs +/- endocrine testing 1-3 months after starting treatment, and then every 6-12 months
what are the most important indicators of response to treatment for PPID?
improvement of clinical signs and insulin status
T/F: ACTH concentrations may not return to the PPID unlikely range despite clinical improvement, and do not always warrant a dose increase
T
