Endocrine dz part 3

• Causes of excessive cortisol levels

  • Pituitary dependent hyperadrenocorticism (PDH) - most common
  • Adrenal tumor
  • Iatrogenic (due to treatment with corticosteroids)
• Pituitary dependent hyperadrenocorticism (PDH)

  • Results in excessive amounts of ACTH; this results in hyperplasia of the adrenal glands, which is subsequently followed by over secretion of cortisol
• Breeds predisposed to PDH

  • Poodles
  • Dachshunds
  • Terriers
  • Beagles
  • German Shepherds
  • Boston Terriers
  • Boxers
• Breeds predisposed to adrenal tumor

  • Toy Poodles
  • German Shepherds
  • Dachshunds
  • Labrador Retrievers
  • Some Terrier breeds
• Clinical signs of Cushing's Disease

  • PU or PD
  • Polyphagia
  • Excessive panting
  • Abdominal enlargement (related to abdominal muscle weakness); obesity
  • Muscle weakness, lethargy, lameness
  • Bilateral, symmetric alopecia; pruritus; pyoderma
  • Calcinosis cutis (firm plaques of calcium under the skin), but infrequent
  • Abnormal gonadal function: lack of estrus; soft, small testicles
• Diagnostic tests for Cushing's Disease

  • Serum chemistry abnormalities
  • ACTH stimulation test
  • Dexamethasone suppression test
• Treatments for Cushing's Disease

  • Surgical removal of adrenal tumor(s)
  • Medical management - life-long: Trilostane (Vetoryl), Mitotane (Lysodren, o,p-DDD)
• Primary Hyperparathyroidism

  Hypercalcemia results from the excessive secretion of parathyroid hormone (PTH), which is usually caused by the presence of parathyroid adenoma or carcinoma
• Clinical signs of Primary Hyperparathyroidism

  • Many animals show no clinical signs
  • Anorexia
  • Vomiting
  • Constipation
  • PU or PD
  • Listlessness(fatique), obtunded(lack of pain), coma, or all
  • Urinary calculi(stones), cystitis(UTI), or both
  • Incontinence
  • Weakness, exercise intolerance
• Diagnostic tests for Primary Hyperparathyroidism

  • Hypercalcemia is the hallmark (serum total calcium levels >12 mg/dL)
  • Low to low-normal phosphorus concentrations
  • PTH levels
• Treatments for Primary Hyperparathyroidism

  • Surgical removal or ablation of mass
  • Monitor for hypocalcemia
• Causes of Hypocalcemia/Hypoparathyroidism

  • Parathyroid-related disease
  • Chronic renal failure
  • Acute pancreatitis
  • Puerperal tetany (eclampsia)
• Chronic renal failure is a common cause of hypocalcemia in dogs and cats
• Calcium precipitates within pancreatic tissue can cause mild hypocalcemia in acute pancreatitis
• Puerperal tetany (eclampsia) most commonly occurs in the postpartum period and can be life threatening
• Predisposing factors for puerperal tetany include improper perinatal nutrition, heavy lactation, and inappropriate calcium supplementation
• Causes of excessive cortisol levels

  • Pituitary dependent hyperadrenocorticism (PDH) - most common
  • Adrenal tumor
  • Iatrogenic (due to treatment with corticosteroids)
• Pituitary dependent hyperadrenocorticism (PDH)

  • Results in excessive amounts of ACTH; this results in hyperplasia of the adrenal glands, which is subsequently followed by over secretion of cortisol
• Breeds predisposed to PDH

  • Poodles
  • Dachshunds
  • Terriers
  • Beagles
  • German Shepherds
  • Boston Terriers
  • Boxers
• Breeds predisposed to adrenal tumor

  • Toy Poodles
  • German Shepherds
  • Dachshunds
  • Labrador Retrievers
  • Some Terrier breeds
• Clinical signs of Cushing's Disease

  • PU or PD
  • Polyphagia
  • Excessive panting
  • Abdominal enlargement (related to abdominal muscle weakness); obesity
  • Muscle weakness, lethargy, lameness
  • Bilateral, symmetric alopecia; pruritus; pyoderma
  • Calcinosis cutis (firm plaques of calcium under the skin), but infrequent
  • Abnormal gonadal function: lack of estrus; soft, small testicles
• Diagnostic tests for Cushing's Disease

  • Serum chemistry abnormalities
  • Increased ALP
  • Increased ALT
  • Increased cholesterol level
  • Increased blood glucose concentration
  • Decreased BUN concentration
  • Lipemia
  • ACTH stimulation test
  • Dexamethasone suppression test
• Treatments for Cushing's Disease

  • Surgical removal of adrenal tumor(s)
  • Medical management - life-long
  • Trilostane (Vetoryl)
  • Mitotane (Lysodren, o,p-DDD)
• Primary Hyperparathyroidism


  Hypercalcemia results from the excessive secretion of parathyroid hormone (PTH), which is usually caused by the presence of parathyroid adenoma or carcinoma
• Primary hyperparathyroidism, is Typically diagnosed in older dogs (7 to 11 years of age)
• Clinical signs of Primary Hyperparathyroidism

  • Many animals show no clinical signs
  • Anorexia
  • Vomiting
  • Constipation
  • PU or PD
  • Listlessness(fatique), obtunded(lack of pain), coma, or all
  • Urinary calculi(stones), cystitis(UTI), or both
  • Incontinence
  • Weakness, exercise intolerance
• Diagnostic tests for Primary Hyperparathyroidism


  • Hypercalcemia is the hallmark of parathyroid disease (serum total calcium levels >12 mg/dL)
  • Low to low-normal phosphorus concentrations
  • PTH levels
• Treatments for Primary Hyperparathyroidism


  • Surgical removal or ablation of mass
  • Monitor for hypocalcemia
• Causes of Hypocalcemia/Hypoparathyroidism

  • Parathyroid-related disease
  • Due to accidental surgical removal of the glands during a jaQ
  • Chronic renal failure
  • Acute pancreatitis
  • Puerperal tetany (eclampsia)
• Chronic renal failure is a common cause of hypocalcemia in dogs and cats
• Calcium precipitates within pancreatic tissue can cause mild hypocalcemia in acute pancreatitis
• Puerperal tetany (eclampsia) most commonly occurs in the postpartum period and can be life threatening
• Predisposing factors for puerperal tetany include improper perinatal nutrition, heavy lactation, and inappropriate calcium supplementation
• Diabetes Insipidus (DI)

  Occurs when ADH does not properly signal the kidneys to conserve water
• Pathways leading to diabetes insipidus

  1. Central DI: Inadequate production of ADH by the brain

  2. Nephrogenic DI: Inadequate response to ADH at the kidneys (less common)
• ADH (vasopressin)

  Hormone important to maintain normal hydration status
• Patient is dehydrated

  Pituitary should release ADH, signaling the kidneys to conserve water
• Patients with DI

  • Lose too much water in their urine, becoming dehydrated and thirsty
• Normal water intake and urine output in dogs and cats

  • Water intake: 20-70ml/kg/day
  • Urine output: 20-45ml/kg/day
• Clinical signs of DI

  • Severe PU/PD
  • Drinking > 100ml/kg/day
  • Urinating > 50ml/kg/day