Case Study

Addison’s disease in an 8 year old FS Basset Hound

An 8-year-old FS Basset Hound dog was presented for crying throughout the night and vomiting food, fluid, and mucous. On physical examination, she was found to have pink mucous membranes and a normal body temperature. She had bilateral conjunctivitis as well as a bilateral otitis externa (Malassezia). No abnormalities were noted on auscultation of her heart and lungs. The patient was treated symptomatically as an outpatient with anti-emetics and gastroprotectants. Six days later, the dog returned as she was depressed and lethargic. She was in lateral recumbency upon presentation and she was hypothermic with pale pink, tacky and cold mucous membranes. She was admitted to the hospital for I.V. fluid therapy and blood work. The serum biochemical profile revealed elevated ALT, elevated AST, and elevated GGT, azotemia, hyperproteinemia, hyperalbuminemia, hyperglobulinemia, hyperbilirubinemia, hyperkalemia, hypercalcemia, hyperphosphatemia, hypermagnesemia, hyperamylasemia, and an elevated CK. The CBC showed an elevated hemoglobin and leukocytosis consisting of a monocytosis and eosinophilia.

Sonographic Differential Diagnosis

Subnormal adrenal width with flattened contour. Rule out Addison`s disease (congenital or acquired). The appearance of the adrenals could also be normal for this patient. However, ACTH stimulation is warranted, especially prior to any anesthetic procedure such as endoscopy to investigate gastric pathology.

Image Interpretation

Both adrenal glands were identified by utilizing the land marks of the left renal artery, aorta, and left kidney for the left adrenal, and the vena cava and aorta for the right. Both adrenal glands were subnormal in width (0.25-0.3 cm) flattened in contour, and isoechoic to surrounding fat. In light of appropriate clinical signs (vague GI signs, lethargy, renal failure, poor recovery from anesthesia), ACTH stimulation would be recommended.

DX

Hypoadrenocorticism (Addison`s disease)

Outcome

The patient remained on I.V. fluids and systemic steroids for several days and was subsequently discharged with fludrocortisone and a tapering dose of prednisone. She was to be re-evaluated in two weeks’ time. Blood work at the time of her recheck found all parameters to be within normal limits, including all electrolytes, and she was doing very well clinically.

Comments

Normally the right adrenal gland would be seen clearly in the views used in this study. The lack of a normal right adrenal image, when landmarks are respected, can be used as a trigger to consider Addison`s disease if the clinical profile for Addison`s is present.

Clinical Differential Diagnosis

Hypoadrenocorticism with signs of severe dehydration and shock, neoplasia (hemangiosarcoma, mast cell tumor). Gastrointestinal neoplasm (such as lymphoma, adenocarcinoma, leiomyoma, leiomyosarcoma with secondary perforation, sepsis and shock), hepatic and renal insufficiency secondary to Leptospira sp. infection, necrotizing pancreatitis with hypotensive and/or septic shock.