Endocrine Disease

  1. What are the different types of endocrine diseases?
    • hypothyroidism
    • hyperthyroidism
    • diabetes mellitus
    • hypoadrenocorticism
    • hyperadrenocorticism
  2. What is another name for hypoadrenocoriticism?
    Addison's disease
  3. What is another name for hyperadrenocorticism?
    Cushing's disease
  4. What is another name for diabetes mellitus?
  5. Define endocrinology.
    the study of the endocrine glands and their hormones
  6. What are hormones produced by?
    hormones are produced by ductless glands or tissues
  7. Where are hormones secreted?
    directly into the bloodstream
  8. What do hormones do?
    • chemical messengers
    • signal target cells to perform different functions
    • response to changes in homeostasis
    • interact with specific receptors
    • these receptors generate a specific biologic response
  9. How are hormones released throughout the day?
    • some hormones are released continuously throughout the day
    • some hormones release fluctuates in a rhythm throughout the day
  10. What do feed-back loops do?
    • sense the circulating concentration of a hormone
    • suppress or stimulate production
  11. What are some causes of endocrine disease?
    • feed-back loops non-functional
    • loss of regulation of hormone production
    • gland may work ineffectively or incorrectly
  12. What are the major endocrine glands?
    • thyroid gland
    • parathyroid gland
    • pineal gland
    • pituitary gland
    • adrenal gland
    • kidney
    • ovary
    • testis
    • pancreas
  13. What is the most common type of thyroid disease dogs get?  Cats?
    • dogs:  hypothyroidism
    • cats:  hyperthyroidism
  14. Where is the thyroid gland located?  Can we palpate it?
    • ventral cervical region
    • lateral margins of the trachea
    • usually not palpable in the normal animal
  15. What types of hormones do the thyroid gland produce?
    • T3 - triiodothyronine
    • T4 - tetraiodothyronine
  16. Must have adequate _____ intake to produce thyroid hormones.
  17. What processes do the thyroid hormone affect?
    metabolic processes
  18. No tissue or organ escapes the adverse effect of _____.
    thyroid excess or insufficiency
  19. What are the different causes of canine hypothyroidism?
    • thyroid atrophy
    • lymphocytic thyroiditis
    • neoplastic destruction
    • iatrogenic
  20. What happens with thyroid atrophy?
    adipose tissue replaces thyroid tissue
  21. What happens with lymphocytic thyroiditis?
    • immune mediated
    • antibodies produced against the thyroid
    • slow progressive thyroid tissue destruction
  22. What types of dogs typically get hypothyroidism?
    middle-aged dogs
  23. What are the clinical signs of canine hypothyroidism?
    • weight gain with no change in diet
    • exercise intolerance
    • cold intolerance
    • mental dullness
    • constipation
    • bilateral symmetrical alopecia
    • hyperpigmentation
    • infertility
    • muscle weakness, atrophy
    • bradycardia
    • concurrent endocrine disease
    • lameness
    • cranial nerve paralysis (VII facial)
    • myopathies
    • vestibular disease
  24. What are the main ways to diagnose canine hypothyroidism?
    • mild non-regenerative anemia
    • hypercholesterolemia
    • mild elevation in ALT and ALKP
    • basal T4
    • T4 by RIA - radioimmunoassay
    • TSH response test
    • thyroid antibody concentration
    • ELISA
  25. How do we treat canine hypothyroidism?
    thyroid hormone replacement therapy
  26. What is thyroid hormone replacement therapy?
  27. When will we usually see improvement after treatment for canine hypothyroidism?
    • usually in 1 - 3 weeks
    • skin and coat improvement takes 4 - 6 weeks
    • neurological changes may take months to normalize
  28. When do we measure the hormone levels after starting treatment for canine hypothyroidism?
    4 - 6 weeks after starting treatment
  29. How often do we monitor a dog after starting treatment for hypothyroidism?
    4 - 8 weeks for the next 10 months
  30. What is feline hyperthyroidism?
    excess circulating thyroid hormone
  31. What is the most common endocrinopathy in cats?
  32. What is the signalment for feline hyperthyroidism?
    • middle aged to older cats
    • no gender or sex predilection
  33. What are the clinical signs for feline hyperthyroidism?
    • weight loss
    • polyphagia
    • vomiting
    • PU/PD
    • behavior changes - nervous, hyperactive, aggressive, vocalizing
    • diarrhea
    • heat intolerance
    • panting
    • tachycardia
    • gallop rhythm
    • increased blood pressure
    • blindness due to retinal detachment
    • thin
    • murmurs, pleural effusion, CHF
    • muscle weakness
    • ventroflexion of neck
    • unable to jump to high places
    • dehydration
  34. How do we diagnose feline hyperthyroidism?
    • palpate enlarged thyroid gland
    • mild to moderate elevation in liver enzymes
    • increased BUN and creatinine
    • radiographs
    • basal serum T4 elevated in 95% of hyperthyroid cases
  35. What do we do if the basal T4 test is normal in a cat we suspect has hyperthyroidism?
    repeat in a few weeks because thyroid hormones are known to fluctuate
  36. What are the different treatments for feline hyperthyroidism?
    • surgery
    • oral medications
    • radioactive iodine 131
  37. What kind of oral medication do we use to treat feline hyperthyroidism?
    Tapazole - methimazole
  38. When would we use radioactive iodine 131 to treat feline hyperthyroidism and what does it do?
    • treatment of choice if no renal failure
    • iodine concentrated in thyroid tissue - kills local cells
  39. What are the advantages to using radioactive iodine 131?
    • one injection curative in 95% of cases
    • side effects negligible
    • not invasive
    • destroys intrathoracic thyroid tissue
    • can kill malignant cells at high doses
  40. What are the disadvantages to using radioactive iodine 131?
    • hospitalize throughout the time of radioactive clearance (3 - 10 days)
    • expensive
    • may precipitate onset of renal failure
    • transient hypothyroidism
  41. What do we need to monitor in a cat with hyperthyroidism?
    • renal function
    • T4 levels
  42. What is the general term for diseases marked by excessive urination?
  43. What does mellitus mean?
  44. What does diabetes mellitus involve?
    insulin production or activity
  45. What does insulin do?
    drives glucose into cells for cell usage
  46. What is diabetes most likely due to in dogs?  What is it called?
    • lack of insulin production
    • insulin dependent diabetes mellitus  - type 1
  47. What types of diabetes do cats get?
    • lack of insulin production (insulin dependent diabetes mellitus type 1)
    • decreased action by insulin (non-insulin dependent diabetes mellitus type 2)
  48. What is the average for dogs and cats to get diabetes?
    • dogs:  average age 7-9 years
    • cats:  average age 10 years
  49. Are female dogs or male dogs more at risk for getting diabetes?
    female dogs
  50. What are the clinical signs of diabetes mellitus?
    • PU/PD
    • weight loss
    • polyphagia
    • plantigrade stance in cats
    • underweight, normal, or obese
    • normal to dehydrated
    • diabetic cataracts
    • ketotic diabetes
  51. What is plantigrade stance in cats?
    cats walking with their hocks on the ground
  52. What is diabetic cataracts?
    • high glucose concentration in lens
    • extra glucose converted to sorbitol
    • pulls extra water into the lens and breaks down the lens fibers
  53. How do diabetes become ketotic?
    body metabolizes fat for energy, resulting in build up of ketones
  54. What are the clinical signs of ketotic diabetes?
    • depression
    • weakness
    • tachypnea
    • vomiting
    • acetone breath
  55. How do we diagnose diabetes mellitus?
    • clinical signs
    • fasting blood glucose over 200 mg/dl in the dog (cats blood glucose may be over 200 mg/dl just from stress)
    • glucosuria
    • ketonuria
    • concurrent urinary tract infection
    • serum profile
  56. What do we look for when we are do a serum profile to diagnose diabetes mellitus?
    • hyperglycemia
    • ALT, ALKP increased
    • total bilirubin may be increased
    • increased BUN and creatinine
  57. How do we treat diabetes mellitus?
    • insulin therapy:  SID or BID
    • diet:  high in fiber and complex carbohydrates, feed twice daily prior to insulin injection - at consistent intervals
    • exercise:  consistent amounts and times
    • oral hypoglycemics:  treat clinically stable, uncomplicated NIDDM
  58. What do we monitor in an animal with diabetes mellitus?
    • watch for lessing of PU/PD
    • periodic monitoring of blood glucose concentrations
    • if vomiting or anorexia, give 1/2 dose of insulin or not at all
    • signs of hypoglycemia
  59. What are the signs of hypoglycemia and how do we treat it?
    • signs:  weakness, ataxia, seizures, coma
    • treatment:  karo syrup rubbed on gums and then go to ER
  60. Which is more immediately life-threatening, hypoglycemia or hyperglycemia?
  61. Where are the adrenal glands?
    • 2 glands
    • left and right, dorsal and cranial to each kidney
  62. What are the two regions of the adrenal gland?
    • cortex - outer
    • medulla - inner
  63. What are the hormones produced by the adrenal glands?
    • glucocorticoids
    • mineralocorticoids
    • androgenic (sex) hormones
  64. What do glucocorticoids do?
    • support gluconeogenesis
    • suppress inflammation
    • suppress immune system
    • inhibit cartilage growth and development
    • break down proteins and lipids
    • help body resist the effects of stress
    • important in maintaining homeostasis
    • cortisone, cortisol
  65. What is the principle mineralocorticoid?
  66. What do mineralocorticoids do?
    regulates electrolytes - sodium, potassium, and hydrogen
  67. Which organ do mineralocorticoids target and what do they do?
    • target the kidneys
    • resorb sodium
    • release potassium and hydrogen
    • water comes back into the body with the sodium, affects the water level in the body
  68. What are the different androgenic hormones?
    • male sex hormones
    • female sex hormones
  69. What are the adrenal medulla hormones?  What is the release of these hormones controlled by? What does it prepare the body to do?
    • epinephrine
    • norepinephrine
    • release is controlled by the sympathetic nervous system
    • prepare body or intense physical activity
  70. What are the two hormones that regulate the adrenal gland?
    • CRH:  corticotropin releasing hormone from the hypothalamus which stimulates pituitary to release ACTH
    • ACTH:  adrenocortioctropic hormone which stimulates the adrenal cortex to release cortisol
  71. What is another name for hypoadrenocorticism?
    Addison's disease
  72. What is Addison's disease?
    • atrophy of the adrenal cortex
    • deficiency of secretions of mineralocorticoids and glucocorticoids
  73. Which species is Addison's disease common in?
    not common in dogs, rare in cats
  74. What is the signalment for Addison's disease?
    • middle aged, female
    • any breed
    • found in families of standard poodles and labradors
  75. What are the clinical signs of Addison's disease?
    • episodic weakness, weight loss
    • depression, lethargy
    • PU/PD
    • GI signs - anorexia, vomiting, diarrhea
    • hair loss
  76. What are the clinical signs of Addisonian crisis?
    • weak pulse
    • bradycardia
    • prolonged CRT
    • severe mental depression
    • profound muscle weakness
  77. What lab results do we see with Addison's disease?
    • electrolyte abnormalitis - hyponatremia, hypochloremia, hyperkalemia
    • increased BUN and creatinine
    • acidosis
  78. How do we diagnose Addison's disease?
    • ACTH stimulation test
    • endogenous ACTH levels
  79. What is the ACTH stimulation test?
    • animals with Addison's have a low resting cortisol
    • the additional ACTH injected should stimulate the production of cortisol in normal animals
    • cortisol concentration remains relatively unchanged even with stimulation in animals with Addison's
  80. How do we treat Addison's disease?
    • treat acute crisis with fluid therapy using normal saline, glucocorticoid replacement, desoxycorticosterone pivalate (IM or SQ)
    • maintenance therapy
  81. What are some examples of glucocorticoid replacements?
    • dexamethasone
    • Solu-Delta-Cortef
  82. What kind of maintenance therapy do we provide a patient with Addison's disease?
    • oral fludrocotrisone (Florinef)
    • DOCP - give every 25 - 40 days by injection
    • prednisone supplementation
    • provide double dose of prenisone at times of stress
  83. What is DOCP?  What does it do?
    • desoxycorticosterone pivalate
    • acts like aldosterone
    • increases sodium retention
    • increases potassium excretion
  84. What is another name for hyperadrenocorticism?
    Cushing's disease
  85. What is Cushing's disease and what causes is?
    • hypersecretion of cortisol
    • iatrogenic:  overmedication with corticosteroids
    • adrenal tumor:  excess cortisol produced
    • pituitary tumor:  excess ACTH produced - excess stimulation of adrenal cortex - PDH (pituitary dependant hyperadrenocorticism)
  86. What is the signalment for Cushing's disease?
    • middle aged to older dog
    • 60 - 65% females
  87. What are the clinical signs of Cushing's disease?
    • PU/PD
    • polyphagia
    • heat intolerance, excess panting
    • abdominal enlargement - "pot belly"
    • muscle weakness, lethargy
    • bilateral, symmetrical alopecia, sparing the head and legs
    • pruritus, pyoderma
    • recurrent urinary tract disease
    • insidious onset
  88. How do we diagnose Cushing's disease?
    • Lab tests
    • ACTH stimulation test
    • low dose dexamethasone suppression test
    • ultrasound abdomen - may se adrenal tumor
    • MRI - may see pituitary tumor or adrenal enlargement
  89. What will the lab results show in an animal with Cushings?
    • increased ALT, ALKP
    • increased cholesterol
    • increased blood glucose
    • lipemia
    • decreased BUN
    • UA - UTI, glucosuria, proteinuria,
    • minimally concentrated urine
  90. How do we treat Cushing's disease?
    • adrenal tumor:  adrenalectomy if unilateral
    • radiation of pituitary tumor - expensive, takes 3 weeks, good results
    • mitotane (Lysodren)  - therapy is the most common treatment
    • ketoconazole - inhibits production of certain hormones (steroids, testosterone, cortisol)
    • L-deprenyl (selegilline - Anipryl)
    • trilostane (Modrenal)
  91. What does mitotane therapy do?
    • causes necrosis of the adrenal cortex
    • may affect aldosterone production as well
  92. How do we do mitotane therapy?
    • high initial dose until blood cortisol levels are normal - loading dose
    • lower maintenance dose
    • can give prednisone during stress
  93. What kind of client education do we need to provide about Cushing's disease?
    • serious disease
    • life-long treatment
    • periodic monitoring
    • overdose with mitotane are common - OD signs like Addison's disease
    • prognosis - 20 - 30 months life expectancy
Card Set
Endocrine Disease
Animal Diseases