PPID_Overview

What does PPID stand for?

Pituitary pars intermedia dysfunction.

What causes the increase in ACTH in PPID patients?

Loss of inhibitory dopamine input from the hypothalamus leads to hyperplasia and adenoma formation.

What are the early clinical signs of PPID?

Loss of topline, pot belly, muscle atrophy, hair abnormalities, lethargy.

What is hypertrichosis in the context of PPID?

Pathognomonic excessive hair growth often seen in PPID cases.

What can compression of the optic chiasm due to PPID lead to?

Blindness.

How is laminitis related to PPID?

PPID can exacerbate laminitis, frequently being a presenting complaint.

What is a common result of immune dysfunction in horses with PPID?

Recurrent infections such as sinusitis, skin abscesses, or bronchopneumonia.

Which hormone’s levels are used in the diagnosis of PPID?

ACTH (Adrenocorticotropic hormone).

What two seasons significantly affect ACTH levels in horses?

Autumn and winter.

Why might ACTH be falsely elevated in testing?

Stress, excitement, injury, or active laminitis can cause transient increases in ACTH.

What is the significance of seasonal testing for ACTH levels?

Negative ACTH results in autumn suggest absence of PPID.

What is the first-line treatment for PPID?

Pergolide, a dopamine agonist.

What dose of Pergolide is typically administered initially?

2 µg/kg.

How often should baseline ACTH be rechecked after starting Pergolide treatment?

In 4-6 weeks.

What does hyperhidrosis lead to in PPID affected horses?

Anhidrosis, or no sweating.

What effect do elevated a-MSH levels have in PPID?

They affect appetite and may lead to regional adiposity.

What are common later-stage signs of PPID?

Recurrence of laminitis, immune dysfunction, and PUPD (polyuria and polydipsia).

What is the TRH stimulation test used for in diagnosing PPID?

To confirm the diagnosis when clinical suspicion is low.

In which situation should ACTH testing be postponed?

If the horse is active laminitic or in severe pain.

What is one possible consequence of suspensory ligament breakdown in PPID horses?

Collagen disruption.

What is the expected improvement after 1 month on Pergolide?

Improved attitude and activity, and laminitis control.

What is a myth regarding the relationship between PPID and Cushing’s disease?

PPID is not the same as Cushing’s disease.

What histological changes are associated with PPID?

Oxidative damage, accumulation of a-synuclein and lipofuscin.

What clinical sign indicates abnormal shedding in PPID?

Long curly hair or poor performance.

What are the baseline ACTH level thresholds in autumn for suspected PPID?

What considerations should be made regarding other diseases in PPID diagnosis?

Consider Equine Metabolic Syndrome (EMS) as a concurrent or alternative diagnosis.

What other treatments for PPID are available besides Pergolide?

Other off-licensed treatments may exist but will require monitoring.

What signs might indicate secondary infections in horses with PPID?

Recurrent infections like sinusitis or foot abscesses.

What is a possible sign of hormonal imbalance related to lactation in PPID?

Pseudo-lactation due to lack of dopaminergic control.

What is the role of a-MSH in the context of lethargy in PPID?

Increased levels lead to excessive lethargy due to a sedative effect.

How can hair abnormalities in PPID be explained?

Increased a-MSH may lead to more hair in the anagen phase.

What is the significance of muscle atrophy in PPID?

Due to lack of musculature; common sign of the disease.

What factor should be considered when diagnosing in younger horses (

Other potential causes of signs should be considered before confirming PPID.

What should be done within 4 hours during insulin dysregulation testing?

Centrifugation for plasma separation.

What can be expected after 6 months of Pergolide treatment?

Improvement in hair coat, muscle mass, and reduction in laminitis.

How is seasonal interpretation of ACTH results significant in confirming PPID?

It helps to assess likelihood of PPID based on seasonal variations in ACTH levels.

What diagnostic test can help identify false negatives in confirming PPID?

TRH stimulation test.

What is a common age risk factor for developing PPID in horses?

Older age, as PPID onset is slow and insidious.

Why is it crucial to monitor ACTH levels regularly in horses on treatment for PPID?

To ensure the appropriate dose of Pergolide is maintained for effective management.