Case Study

Bilateral adrenal hypertrophy in a 12 year old MN Yorkshire Terrier

A 12 year old NM Yorkshire Terrier dog with a history of elevated ALP activity, elevated cholesterol, elevated BUN, and elevated BUN/creatinine ratio was presented. Abnormalities on physical examination were hair loss on the lower back, joint disease, cyst on top of the head, and a mass on the right side of the hock. The only significant finding on urinalysis was microalbuminuria. Serum biochemistry showed elevated ALP activity, hyperglobulinemia, hypercholesterolemia, and elevated BUN and elevated BUN/Creatinine ratio. On ACTH stimulation, the post sample showed hypercortisolemia.

DX

Hyperadrenocorticism

Sonographic Differential Diagnosis

Bilateral adrenal hypertrophy consistent with hyperadrenocorticism

Image Interpretation

The adrenal glands presented bilateral uniform hypertrophy for this size patient. Contour was swollen yet uniform. No evidence of vascular invasion or unilateral neoplasia was evident. These changes are consistent with, but not specific to, pituitary dependent hyperadrenocorticism (PDH). Dynamic function tests and ACTH plasma level would be necessary to confirm PDH.

Outcome

Hyperadrenocorticism was diagnosed on ACTH stimulation test. Blood pressure was within normal limits. The patient was treated with trilostane, Denamarin, and Actigal. Recheck biochemistry 3 months later showed a decrease in ALP activity, urea, BUN/Creat ratio, and cholesterol. The patient was started on the Hill’s J/D diet. Both the cyst on the head and the hock mass were surgically excised.

Clinical Differential Diagnosis

Primary hyperadrenocorticism (adrenal neoplasia), secondary Cushing’s disease (pituitary dependent), early renal disease, glomerular disease, cutaneous cyst, neoplasia.