S

Thumphy Carter

(Acc#153311)

Trisha OuraSeptember 26, 2011

Thumphy

15 yo MC DLH presenting for vomiting, neck ventroflexion, lethargy rDVM bloodwork: ↓K, Azotemic

At NCSU: IV/VI heart murmur, generalized

weakness, ataxia, enlarged thyroid

Bloodwork: ↓K+, metabolic alkalosis, hyposthenuria

Ultrasound

Aldosterone

Function: BP & ECF volume homeostasis Action: K+ & H+ secretion, Na+ & Cl- resorption

(collecting ducts/distal tubules) Physiology:

Zona Glomerulosa

Aldosterone

Extracellular [K+]

blood volume (RBF)

JG appartu

s

Renin

Angiotensinogen ATI (liver) ATII (lungs)

Primary Hyperaldosteronism in

Cats Older, no sex/breed predilection Clinical signs: weakness, cervical ventroflexion,

lethargy, +/- changes secondary to BP Bloodwork: azotemia, isosthenuria, +/- hypokalemia,

[renin] due to negative feedback, [aldosterone] Usually unilateral adenoma or carcinoma

(11/23 = carcinoma, 9 = adenoma, 3 = hyperplasia) Can be part of multiple endocrine neoplasia (MEN)

Other DDX:

Secondary hyperaldosteronism Primary increases in renin: renal

disease, heart disease Hypokalemia ddx: renal failure, liver

failure, GI disease, hyperthyroidism, DM FYI: rare in dogs, as of 2004 only 2 case

reports in the literature

Treatment

Surgical (treatment of choice) Good prognosis (if no vascular invasion/thrombus) Survival of several years No change in prognosis with carcinoma vs.

adenoma Medical

Spironolactone (aldosterone antagonist at DCT) K+ supplement Anti-hypertensive drugs Survival months-years

Thumphy

Discharged Rx:

Spironolactone, potassium supplements

Recommend return for adrenalectomy

Improved with Rx, no new follow-up

References

Ash RA, et al. Primary hyperaldosteronism in the cat: a series of 13 cases. J Fel Med Surg 2005;7:173-182.

Flood SM, et al. Primary hyperaldosteronism in two cats. J Amer Anim Hosp Assoc 1999;35:411-416

Moore LE, DS Biller, TA Smith. Use of abdominal ultrasonography in the diagnosis of primary hyperaldosteronism in a cat. JAVMA 2000;217:213-215.

Shculman RL. Feline primary hyperaldosteronism. Vet Clin Small Anim 2010;40:353-359.