EqMed Q2, Endocrine

  1. What is big head disease or bran disease?

    Cause?
    Nutritional 2' Hyperparathyroidism

    High Phospherous diet
  2. How does Phosphorous affect vitamin D?
    • Excess P=
    • Stimulates parathyroid gland=
    • Inhibits vit D Synthesis=
    • Low vit D=
    • Stimulates parathyroid gland
  3. Expected serum Ca with hyperparathyroidism?
    • Normal
    • Dz is slowly progressive
  4. C/S associated with nutritional hyperparathyroidism? 6
    • Facial bone enlargement
    • Difficulty chewing dt bone loss
    • Molar fractures
    • Spontaneous long bone fractures
    • Unthrifty
    • Lameness
  5. Tx for nutritional hyperparathyroidism? 4

    Prognosis?
    • Eliminate grain and oxalates from diet
    • Supplement Ca (want ratio 3 or 4:1)
    • NSAIDs +/-
    • Confinement +/-

    Complete recovery may not be possible
  6. Hypothyroidism is a rare condition in horses. What are lab findings that support this diagnosis?
    • Decreased T4
    • Increased TRH and TSH
  7. C/S associated with hypothyroidism? 5
    • Obesity
    • Anhidrosis (inability to sweat)
    • Laminitis
    • Rhabdomyolysis
    • Infertility
  8. Common thyroid neoplasia?
    Benign or malignant?
    Adenoma

    • Benign/nonfunctional
    • (enlarged and palpable)
  9. Expected T4 with thyroid adenoma?
    WNL
  10. Recommended Yx for thyroid adenoma?
    • Tx unnecessary
    • Unless compresses trachea/esophagus - then thyroid supplement is warranted
  11. Equine cushings syndrome is AKA?
    • Pars Pituitary Intermedia Dysfunction
    • (minimal adrenal involvement in equine cushings)
  12. what is common age and most common sign associated with PPI/Cushings?
    • Middle aged to older (>15yr)
    • Hirsutism
  13. Role of dopamine in equine cushings?
    Inhibits melanotrope hormone

    • No Dopamine
    •    ⇩
    • Inc. Melanotrope Horm.
    •    ⇩
    • Hypertrophy/hyperplasia of PPI
  14. Hypertrophy of pars intermedia causes excess release of ____, and therefore...
    • *increased POMC*
    •    ⇩ 
    • α-MSH (melanocyte stim hormone)
    • β-endorphin
    • CLIP (corticotropin like intermediate lobe peptide)
  15. What leads to C/S's associated with cushings?
    • Enlarged/highly active pars intermedia *POMC*
    • Compression of adjacent hypothalmic tissues
  16. How does cushings affect immune system?
    • α-MSH
    • Decreases immune response
    • Chronic infections & poor wound healing
  17. how does cushings affect physical appearance? how does it affect behavior?
    • Hirsutism
    • Coat color change
    • Guard hairs on chin
    • Abnormal fat deposition

    • Docile
    • Seizures
    • Blindness
  18. How does cushings affect limbs?
    • Laxity in suspensory ligament
    • Chronic laminitis
  19. What is another endocrine disorder 2' to cushings?
    Type 2 DM
  20. Dx tests for cushings? 4
    • Endogenous ACTH
    • ACTH Stim
    • Measure for Hyperinsulinemia
    • TRH stim (directly stimulates melanotropes)
  21. How is dexamethasone suppression test done in the horse?

    What is indication of +?
    • T0 (Baseline cortisol)
    • T15 Hrs
    • T20 Hrs (overnight)

    +Cushings if fail to suppress cortisol
  22. What is MOA of pergolide as treatment for cushings?
    • Dopamine antagonist
    • (side effects include V/D, anorexia)
  23. MOA of Cyproheptadine as Tx for cushings?
    • Blocks Serotonin
    •  = Interferes with POMC
    • (expensive and not readily available)
  24. Prognosis for horse with cushings?
    • Can be managed for years with pergolide and good husbandry/foot care
    • (most common reason for euthanasia is laminitis complications)
  25. what is cause of laminitis related to endocrinopathy?
    Insulin resistance/Hyperinsulinemia
  26. What characterizes equine metabolic syndrome?
    • Regional adiposity (fat deposition)
    • Insuline resistance
    • "easy keepers"
  27. What is signalment of affected horses?
    • Adult (>5yr)
    • No sex predilection
    • Ponies>Morgans>Arabs>Fjords
  28. Dx for metabolic syndrome?
    Resting hyperinsulinemia >30 uu/ml defines

    Combined Glucose-Insulin test to ck for insulin resistance
  29. How is glucose-insulin test done?

    + Test?
    • Baseline glucose
    • IV dextrose + insulin
    • Elevated BG >45min = insulin resistance
  30. how is metabolic syndrome treated/managed? 6
    • Wt loss is critical (remove CHO, feed grass hay)
    • Soak hay to decr. CHO
    • Grazing muzzle
    • Exercise/swimming
    • Manage laminitis
    • Levothyroxine
  31. what are goals of using levothyroxine to manage metabolic syndrome?
    • Lower body weight
    • Improves insulin sensitivity
    • (Short term only, stop when ideal body weight  or <6 mo)
Author
HLW
ID
212926
Card Set
EqMed Q2, Endocrine
Description
EqMed Q2, Endocrine
Updated