42 Questions
What is the preferred diagnostic test for Cushing disease?
Low-dose dexamethasone suppression test
Which of the following statements about Cushing syndrome is true?
Pituitary-dependent hyperadrenocorticism is less common than adrenal-dependent disease in dogs
What is the characteristic age range of dogs affected by Cushing disease?
7-12 years old
Which term encompasses both pituitary-dependent and adrenal-dependent causes of elevated cortisol concentrations?
Cushing syndrome
What is the most common disadvantage of the LDDS test in dogs with nonadrenal illness?
Low specificity
What is the pattern of suppression and escape seen in 30% of dogs with PDH during an LDDS test?
Suppression at 3 or 4 hours followed by escape at 8 hours
What diagnostic tool uses three doses of dexamethasone to measure urine cortisol in cats and dogs?
Oral LDDS test using UCCR
What is a possible reason for negative ACTH stimulation and LDDS tests in dogs with adrenal sex steroid excess?
Excess cortisol precursors
Why may dynamic adrenal testing be necessary for dogs with adrenal sex steroid excess?
To measure sex steroids in addition to cortisol
Which test is the most reliable way to differentiate between PDH and adrenal tumors in dogs according to the text?
Measurement of endogenous plasma ACTH concentrations
What is the purpose of adding the protease inhibitor aprotinin to whole blood in EDTA tubes as mentioned in the text?
To inhibit ACTH degradation
What is a common manifestation of Cushing disease in cats?
Polydipsia and polyuria
Why is SAP seldom increased in cats according to the text?
Because cats lack the specific hepatic isoenzyme for it
What is the most suitable test to differentiate healthy dogs from those with hyperadrenocorticism according to the text?
Low-dose dexamethasone suppression test
Which statement about Cushing disease manifestations in cats is false according to the text?
Hypercholesterolemia is common
What causes polydipsia and polyuria in cats with Cushing disease?
Concurrent diabetes mellitus
What is the cause of hyposthenuria in dogs with Cushing disease?
ADH binding interference
Why do dogs with moderate to severe nonadrenal illness show increased UCCR ratios?
Stress of transporting to a vet hospital
What should be done if screening test results for hyperadrenocorticism are inconclusive?
Retest the dog 3–6 months later instead of treating without a definitive diagnosis
What should be used as the screening test of choice for canine hyperadrenocorticism according to the text?
IV low-dose dexamethasone suppression test
What does an increased UCCR need to be confirmed by according to the text?
An IV low-dose dexamethasone suppression (LDDS) test
What is the recommended dosage of mitotane for dogs with PDH?
25–50 mg/kg/day for 7–10 days
What symptom should prompt discontinuation of mitotane therapy in dogs with PDH?
Anorexia, vomiting, and diarrhea
How often should dogs on long-term treatment with mitotane have an examination and ACTH response test?
Every 3–4 months
What is a possible adverse effect of mitotane at the recommended dosage?
Mild hypoglycemia
Which imaging technique is stated as a more sensitive way to identify adrenal tumors?
Ultrasonography
What is a possible consequence of administering trilostane to dogs?
Permanent adrenal insufficiency
How often should trilostane be administered to achieve a decrease in glucocorticoid secretion?
Every 12 hours
What should be monitored to provide an endpoint for mitotane therapy?
< 60 mL/kg/day water consumption
What symptom suggests an expanding pituitary macroadenoma after discontinuation of mitotane?
Ataxia
What is the cortisol concentration indicating excellent control of Cushing's disease pre-trilostane?
138 nmol/L
What is the recommended steroid dose for iatrogenic hyperadrenocorticism, as per the text?
1 mg/kg
Which enzyme does selegiline inhibit in the context of Cushing's disease treatment?
Monoamine oxidase type B
What is the metastatic rate at the time of surgery for adrenal tumors?
5%
What percentage of dogs undergoing unilateral adrenalectomies experience mortality within 1 month after surgery?
~60%
Which therapy typically follows radiation treatment of pituitary tumors in dogs and cats?
Ancillary trilostane or mitotane therapy
What is the typical recurrence rate after hypophysectomy in dogs with PDH?
~20%
What is the main effect of dopamine on ACTH release from the pituitary gland?
Inhibits release
In cases of dogs with large pituitary tumors showing neurologic signs, what treatment is indicated?
Radiation therapy of the pituitary gland
'Cyberknife' and 'gamma knife' are mentioned in relation to which medical procedure?
"Newer types of radiation therapy" for pituitary tumors
What can be a complication arising from rapid reversal of hyperadrenocorticism after hypophysectomy?
Transient diabetes insipidus
What is the median survival time for dogs with carcinomas treated with surgical excision?
778 days
Learn about the LDDS test in dogs with pituitary-dependent hyperadrenocorticism (PDH) and nonadrenal illness. Understand the diagnostic patterns, advantages, and disadvantages of the LDDS test for these conditions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
