Acromegaly, Pituitary dwarfism, Insulinoma Flashcards

1
Q

What disease arises from excess growth hormone?

A

Acromegaly

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2
Q

Where is the tumor located in patients with acromegaly?

A
  • Benign adenoma of the pars distalis (pituitary gland tumor)
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3
Q

How do cats with acromegaly typically present?

A

Usually present as an unstable diabetic with organomegaly, prognathism inferior, stridor/stertor, and neuro signs

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4
Q

What concurrent disease do cats with acromegaly typically have?

A

Diabetes mellitus (uncontrolled)

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5
Q

What clinical effects occur in cats and dogs with acromegaly?

A
  1. Diabetes mellitus
  2. Organomegaly
  3. Soft tissue hypertrophy (stridor, stertor)
  4. Neuro dsyfunction
  5. Cardiomyopathy
  6. Hypertension
  7. Renal failure
  8. Joint disease
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6
Q

What organs become hyperplastic in cats and dogs with acromegaly?

A
  1. Adrenal glands
  2. Parathyroid and thyroid glands
  3. Pancreas
  4. Chondroid hyperplasia in bone
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7
Q

What heart changes can occur in cats and dogs with acromegaly?

A
  • Cardiac hypertrophy
  • Systemic hypertension
  • Arrhythmias, murmur
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8
Q

How is acromegaly in dogs and cats diagnosed?

A
  • Unstable DM
  • Ultrasound changes
  • Measuring GH (hard to do)
  • Measuring IGF-1 (easier than GH)
  • MRI/CT
  • Intact dog on progesterone or in diestrus
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9
Q

What treatment options are available for cats with acromegaly?

A
  • Radiotherapy
  • Hypophysectomy
  • Medical management with insulin, ACEi, diuretics, and B blockers
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10
Q

A cat presenting with uncontrolled diabetes mellitus, hypertension, and “club feet” is diagnosed with acromegaly. The owner can only afford medical management. What drugs do you prescribe?

A
  1. Insulin (no more than 1IU/kg BID)
  2. ACEi
  3. Diuretics
  4. Beta blockers

(Insulin for DM, ACEi to ↓ BP and control proteinuria, Diuretics to help with CHF and effusions, B blocker to control arrhythmias)

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11
Q

What is the cause of canine acromegaly?

A
  • Intact female treated with progesterone to prevent estrus
  • Intact female in diestrus
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12
Q

Why is history a crucial part in diagnosing acromegaly in dogs?

A

Occurs in intact females receiving progesterone or intact females in diestrus

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13
Q

An intact female dog is diagnosed with acromegaly. What is the treatment plan?

A
  • Progesterone withdrawal or OVH (spay) reduces GH and IGF-1 levels
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14
Q

Which pituitary tumor in dogs can be controlled by spaying the animal?

A

Canine acromegaly

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15
Q

List the 6 hormones synthesized and secreted by the anterior pituitary

A
  1. GH
  2. ACTH
  3. TSH
  4. PRL
  5. FSH
  6. LH
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16
Q

What is the cause of proportional dwarfism in dogs?

A

Congenital defect in the anterior pituitary resulting in ↓ GH, TSH, PRL, and gonadotropins

17
Q

Which hormone is unaffected in dogs with pituitary dwarfism?

A. TSH
B. ACTH
C. GH
D. PRL

A

B. ACTH

18
Q

What dog breed is most associated with pituitary dwarfism?

A

GSD

19
Q

What clinical signs do dogs with pituitary dwarfism typically present with?

A
  • Proportionate dwarfism
  • Retention of puppy coat
  • Hyperpigmentation
  • CRF from undeveloped kidneys
  • Slow and dull from underactive thyroid
  • Failure of testis to descend
20
Q

How is pituitary dwarfism in dogs diagnosed?

A
  • Failure to respond to pituitary stim testing
  • Low TSH
  • Low GH
21
Q

What is the treatment protocol for a dog with pituitary dwarfism?

A
  • Levothyroxine (T4 supplement)
  • Porcine GH
22
Q

What is the prognosis for a dog with pituitary dwarfism?

A
  • 3-5 years without treatment
  • Longer with tx
23
Q

What is the most common endocrine pancreatic tumor in dogs?

A

Insulinoma

24
Q

Where are most insulinomas in dogs located?

A

Left lobe of the pancreas

25
Q

What is the first approach in treating a dog with insulinoma?

A

Surgical resection

26
Q

If surgical resection is not an option, how can insulinoma in dogs be medically managed?

A
  1. Frequent small meals
  2. High protein, fat, and carb diet
  3. Prednisolone (inhibits insulin)
  4. Diazoxide (inhibits insulin)
  5. Octreotide (inhibits insulin)
27
Q

List the pathological causes of hypoglycemia in dogs

A
  1. Pancreatic or hepatic neoplasia
  2. Insulinoma
  3. Hypoadrenocorticism / Addisons
  4. Sepsis
28
Q

Which of the following is not a differential for hypoglycemia in a canine patient?

A. Insulinoma
B. Hyperadrenocorticism
C. Sepsis
D. Hypoadrenocorticism

A

B. Hyperadrenocorticism

29
Q

What clinical signs do dogs with insulinoma present with?

A
  • Non specific, waxing and waning CS
  • CS of hypoglycemia
  • Seizures
  • Collapse
  • Ataxia
  • Weakness
30
Q

What clin path changes can be seen in dogs with insulinoma?

A
  • Low BG
  • Azotemia
  • Normal to ↓ BP
  • Normal or isothenuric urine
  • Normal CBC

(fairly non specific findings)

31
Q

How can insulinoma in dogs be diagnosed?

A
  • Elevated or high normal insulin in the face of hypoglycemia
  • Can’t measure insulin if glucose is normal, must be hypoglycemic when testing
  • Low fructosamine
  • Ultrasound / CT
32
Q

True or False: Majority of dogs with insulinoma have a benign adenoma of the endocrine pancreas

A

False, can be adenoma or carcinoma, metastasis common if carcinoma

33
Q

Which endocrinopathy in cats can result in stridor / stertor sounds?

A

Acromegaly (due to soft tissue hypertrophy)

34
Q

Why should no more than 1 IU/kg of insulin BID be given to cats with acromegaly?

A

GH and IGF-1 secreted in bursts, insulin can result in intermittent hypoglycemia

35
Q

An intact female dog receiving progesterone is at risk for developing what endocrinopathy?

A

Canine acromegaly

36
Q

What is the main cause of death in dogs with pituitary dwarfism?

A

Underdeveloped kidneys causing chronic renal failure