Feline Adrenal Gland Disease (Rolph) Flashcards
What’s unusual about feline hypoadrenocorticism?
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Primary hypoadrenocorticism = rare
- Majority idiopathic, occasionally secondary to neopalsia/trauma
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Secondary hypoadrenocorticis
- __Frequently post-administration of corticosteroids or megestrol acetate
Describe the signalment for feline hypoadrenocorticism.
- 18 mos. - 14 yrs.
- No gender or breed disposition
What are some clinical signs associated with feline hypoadrenocorticism?
Up to 4 mos., waxing/waning
- Lethargy
- Depression
- Anorexia
- Weight loss
- Collapse
- Weakness
- Dysphagia
- Vomiting
- PU/PD
What would CBC and biochemistry results look like for feline hypoadrenocorticism?
Often normal
- Occasionally normocytic, normochromic, non-regenerative anemia, lymphocytosis and eosinophilia
- Azotemia (pre-renal)
- Hyperphosphatemia
- Mild increases in ALT, ALP, tBil
What would urinalysis results look like in feline hypoadrenocorticism?
USG typically < 1.030
- Due to medullary washout from hyponatremia and lack of vasopression
What are expected electrolyte abnormalities in feline hypoadrenocorticism?
** OFTEN TELL-TALE SIGNS **
- Hyponatremia
- Hypochloremia
- Hyperkalemia
- Occasionally hypochloremia and hypo/hypercalcemia
How do you diagnose feline hypoadrenocorticism?
ACTH Stimulation Test ± ACTH assay
- Elevated ACTH concentration in a cat w/ hypoadrenocorticism CONFIRMS primary disease
Describe treatment for feline hypoadrenocorticism?
Same as for dogs
- Aggressive IVF
- Address hyperkalemia/dysrhythmias
- Glucocorticoid replacement (IV dexamethasone, prednisolone)
- Mineralocorticoid replacement (fludrocortisone acetate or DOCP IM)
How long does it take for patients to respond to feline hypoadrenocorticism treatment?
About 3-5 days
What’s the prognosis for cats surviving feline hypoadrenocorticism?
Excellent (can live for many months/years)
What is feline hyperaldosteronism?
Hyperplasia or neoplasia of adrenal glands → overproduction of aldosterone
- Also known as Conn’s syndrome
Where is aldosterone released from, what does it affect, and what does it stimulate?
- Released from zona glomerulosa (mediated by AngIII, increased K+, corticotrophin)
- Affects mineralocorticoid receptors in distal renal tubules, colon, salivary glands
- Stimulates: Na reabsorption, K and hydrogen excretion
What is aldosterone’s role in the kidneys?
Traditionally as hormone controlling Na+ reabsoprtion and K+ excretion by acting on:
- Late distal convoluted tubule
- Connecting tubules
- Principle cells of collecting ducts
In the kidney, what does aldosterone activate?
- Epithelial Na+ Channel (ENaC)
- Sodium chloride co-transporter (NCC)
- Na,K-ATPase
What’s the relationship between aldosterone and vasoconstriction?
Aldosterone MEDIATES vasoconstriction
- Increases prostacyclin production
- Potential role in upregulating ET production (ET-1: vasopressor)
- Upregulates ACE, local production of AngII
- Upregulates the AT1 receptors
