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Please refer to Adrenal Testing in Dogs and Adrenal Testing in Cats for additional information.
Does the VDL offer an “adrenal panel”?
No. The VDL offers measurement of cortisol, aldosterone, progesterone and testosterone as standalone tests. Adrenal testing on dogs that have received glucocorticoid therapy:
- Note: patient MUST NOT receive prednisolone, prednisolone, or hydrocortisone for at least 12 – 24 hours before measuring cortisol levels or cross-reaction (iatrogenic increase) in the assay is possible. Dexamethasone does not cross-react in the cortisol assay.
- When testing dogs with suspicion for hypoadrenocorticism (Addison’s disease), measuring both cortisol and aldosterone can be helpful.
- There is not an easy answer for “ideal withdrawal period” to avoid adrenal suppressive effects from prior glucocorticoid treatment. Multiple variables are involved including the dose, duration of treatment, and an individual’s sensitivity to adrenal suppression; therefore unpredictable. The general recommendation is 6-8 weeks after tapering; however, some dogs may be suppressed for months. Additionally, if there is suspicion for Addison’s disease, it could compromise the patient to be off steroids for an extended period. ACTH stimulation testing in that case will usually still be able to rule OUT hypoadrenocorticism with a short withdrawal IF results are close to normal, but abnormal results will need cautious interpretation.
I made a mistake during adrenal function testing. When can I repeat the test?
- Dexamethasone suppression testing can be repeated after 48 hours. ACTH stimulation testing can be repeated after 24 hours.
- If performing a low dose dexamethasone suppression test and the dose administered was close to 0.1 mg/kg IV, then the test can be interpreted as a high dose dexamethasone test.
- If dexamethasone went perivascular, the test would still be reliable if the patient suppresses normally. A positive result (incomplete suppression) should be interpreted with caution given that there have not been studies to assess the effect of perivascular injection.
- A published study found no effect of results with perivascular accidents during ACTH stimulation testing.
- Giving a higher dose of ACTH than what is recommended in the protocol will not affect interpretation of the results.
Can I use Dexamethasone SP for dexamethasone suppression testing?
Yes. Calculate the dose using the “equivalent dose” mg/ml indicated on the label.
My client gives trilostane once a day, at night; how can I monitor with a 4-6 hour post ACTH stimulation test (recommended protocol by manufacturer of Vetoryl)?
Transition to morning administration for at least a few days before the test.
If you are requesting an interpretation on cortisol/ACTH stimulation testing on a patient receiving trilostane, please include the dose and frequency of trilostane, timing of the sample in relation to administration of trilostane, and if the monitoring test is early in the treatment phase (4 weeks or less) on the submission form.