Case 4 Endocrinology Part 2 Answers

1 Test / Procedure: LDDS
Results:

pre-cortisol: 152 nmol/L (28-110 nmol/L); 8-hour post: 135 nmol/L (<28 nmol/L)

Review indications & protocol in notes.

What is your assessment?
The dog failed to suppress which strongly suggestive of hyperadrenocoricism. A test to differentiate adrenal tumor from pituitary is indicated.

2 Test / Procedure: HDDS
Results:

Pre cortisol: 147 nmol/l (28-110 nmol/l): 8 hr Post: 31 nmol/l (50% or greater suppression)

Review indications & protocol in notes.

What is your assessment?
Since the dog showed suppression with high dose dexamethasone, the diagnosis is PDH.

3 Test / Procedure: Urine culture
Results:

Staphylococcus intermedius (>100,000/ml)

Review indications & protocol in notes.

What is your assessment?
This is a common organism responsible for UTI in dogs. It should be treated with appropriate antibiotics. UTI is a common finding in hyperadrenocorticism since cortisol is metabolized and secreted in high concentration in the urine.

4 Test / Procedure: Total T-4
Results:

3.5 ng/ml (5-22 ng/ml)

Review indications & protocol in notes.

What is your assessment?
The total T4 is below normal. While this might indicate primary hypothyroidism, non-thyroidial illness and drugs may also decrease T4 in euthyroid dogs. In this case, glucocorticoid suppression of T4 should be suspected.

5 Test / Procedure: Free T-4 (fT4)
Results:

0.5 ng/dl (0.3-2.0 ng/dl)

Review indications & protocol in notes.

What is your assessment?
fT4 is in low normal range. This can be expected in euthyroid sick animals or from drug suppression. It is likely that glucorticoid suppression explains this finding.

B. Final Diagnosis

1. Corneal ulcer with perforation and subsequent anterior uveitis. 2. PDH. 3. Urinary tract infection

C. Therapeutic Plan

1. UTI: Clavimox orally bid for 3 weeks. 2. PDH: 3 medical options exist, lysodren (o-pDDD, mitotane), ketoconizole and deprenyl (Anipyrl). Lysodren is the most effective since it causes selective necrosis of the zona fasiculata and reticularis. See notes for dosage schedules and comparison to other forms of medical management.

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To view other dermatological manifestations of hyperadrenocorticism, click on the image at right.

Endocrinology Case 4

Expanded Case Evaluation
Expert's Answers

Endocrinology Case 4

Expanded Case Evaluation Expert's Answers

Expanded Case Evaluation
Expert's Answers