Quiz: How to Choose the Right Test for Hyperadrenocorticism

Marie Chartier, DVM, DACVIM, VCA Roberts Animal Hospital, Hanover, Massachusetts

ArticleQuizLast Updated December 20231 min readPeer Reviewed
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The Case

An 8-year-old, 71-lb (32-kg) spayed Labrador retriever is presented for 3 episodes of urinary incontinence over a 2-month period. Her owner indicates there have been no changes in appetite or energy level and no episodes of vomiting or diarrhea. There have been mild increases in water consumption, frequency of urination, and signs of anxiety over the past few months. Stranguria and hematuria have not been observed.  

Physical examination and CBC results are within normal limits. Results of a nonfasting serum chemistry profile show elevations in ALP, ALT, and cholesterol (Table 1). Urinalysis shows hyposthenuria (1.006) and 2+ proteinuria with an inactive sediment. 

Table 1: Serum Chemistry Profile Results*

Test

Result

Reference Interval

Total protein

5.9 g/dL

5-74 g/dL

Albumin

3.2 g/dL

2.7-4.4 g/dL

Globulin

2.7 g/dL

1.6-3.6 g/dL

Albumin:globulin ratio

1.2

0.8-2

AST

28 mIU/mL

15-66 mIU/mL

ALT

175 mIU/mL

12-118 mIU/mL

ALP

1,737 mIU/mL

5-131 mIU/mL

Gamma-glutamyl transferase

10 mIU/mL

1-12 mIU/mL

Total bilirubin

0.1 mg/dL

0.1-0.3 mg/dL

Urea nitrogen

12 mg/dL

6-31 mg/dL

Creatinine

0.7 mg/dL

0.5-1.6 mg/dL

BUN:creatinine ratio

17

4-27

Phosphorus

3.9 mg/dL

2.5-6 mg/dL

Glucose

86 mg/dL

70-138 mg/dL

Calcium

9.4 mg/dL

8.9-11.4 mg/dL

Corrected calcium

9.7 mg/dL

--

Magnesium

2 mEq/L

1.5-2.5 mEq/L

Sodium

145 mEq/L

139-154 mEq/L

Potassium

4.6 mEq/L

3.6-5.5 mEq/L

Sodium:potassium ratio

32

27-38

Chloride

110 mEq/L

102-120 mEq/L

Cholesterol

416 mg/dL

92-324 mg/dL

Triglycerides

98 mg/dL

29-291 mg/dL

Amylase

466 mIU/mL

290-1,125 mIU/mL

Creatine phosphokinase

100 mIU/mL

59-895 mIU/mL

*Bold indicates values outside the reference interval.

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Conclusion 

The patient had a complete response to treatment with trilostane. PU/PD, anxiety, and urinary incontinence resolved; ACTH stimulation test results improved. A long-term monitoring plan was discussed with the owner.