410 DISEASES/DISORDERS
CLINICAL FEATURES
May be associated with rat tail, pinnal folding, pot belly appearance (Figure 27.1).
Seborrheic coat.
Skin becomes markedly thin (atrophic) and fragile; easily torn with normal handling
(Figures 27.2–27.6).
Skin bleeds minimally upon tearing (Figure 27.7).
Multiple both new and healing lacerations; may become secondarily infected (Figure
27.8).
Partial (thinning) to complete alopecia of the truncal region may be noted (Figure
27.9).
HAC cases: polyphagia, polyuria, polydipsia, lethargy, weight change (gain or loss),
unkempt coat, coat color change, recurrent infections, muscle atrophy, bruising,
peripheral neuropathy, CNS abnormality (circling, vocalization, obtundation, blind-
ness, incoordination).Iatrogenic HAC: risk for corticosteroid-associated congestive heart failure.
DIFFERENTIAL DIAGNOSIS
Cutaneous asthenia
Trauma/recurrent skin injury
Hyperthyroidism
Feline paraneoplastic syndrome: pancreatic neoplasia, hepatic lipidosis, cholangio-
carcinoma
DIAGNOSTICS
CBC/Biochemistry/Urinalysis
HAC: inconsistent increases in serum ALT, alkaline phosphatase and cholesterol; mild
proteinuria.
Approximately 80–90% of cats with hyperadrenocorticism have concurrent diabetes
mellitus (hyperglycemia, glucosuria).
Other Laboratory Tests
Urine cortisol-creatinine ratio: screening test as in dogs; may be elevated in cats with
HAC; may be used as a diagnostic test to distinguish between ADH and PDH.
ACTH stimulation test: up to 70% of cats with hyperadrenocorticism have an exagger-
ated response; false positives due to systemic illness; best test to distinguish between
spontaneous and iatrogenic HAC; suppressed response may be due to iatrogenic HAC