Effects of a mock ultrasonographic procedure on cortisol concentrations during low-dose dexamethasone suppression testing in clinically normal adult dogs.
OBJECTIVE
To determine whether the stress of an ultrasonographic procedure would interfere with the suppressive effect of dexamethasone during a low-dose dexamethasone suppression test (LDDST) in healthy dogs.


METHODS
6 clinically normal adult dogs.


METHODS
In phase 1, an LDDST was performed 5 times at weekly intervals in each dog. Serum samples were obtained 0, 2, 4, 6, and 8 hours after dexamethasone injection. A mock 20-minute abdominal ultrasonographic examination was performed on all dogs at each time point during the LDDST on weeks 2 through 5. In phase 2, serum cortisol concentrations were measured before and immediately after a 20-minute mock abdominal ultrasonographic examination, as described for phase 1.


RESULTS
We did not detect significant differences after dexamethasone injection when comparing median cortisol concentrations for weeks 2 to 5 (mock ultrasonographic procedure) with median concentration for week 1 (no mock ultrasonographic procedure). For 5 of the 6 dogs, cortisol concentrations after dexamethasone injection decreased to < 35.9 nmol/L after each mock ultrasonographic procedure and remained low for the duration of the LDDST. In phase 2, all dogs had significant increases in cortisol concentrations immediately after the mock ultrasonographic procedure.


CONCLUSIONS
A 20-minute mock abdominal ultrasonographic examination performed during LDDST did not alter results of the LDDST in most dogs. Cortisol concentrations measured immediately after a mock ultrasonographic examination were significantly increased. Ultrasonographic procedures should be performed a minimum of 2 hours before collection of samples that will be used to measure cortisol concentrations.
May
Elizabeth R
ER
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4544, USA.
Frank
Linda A
LA
Hnilica
Keith A
KA
Lane
India F
IF
D000005:Abdomen / Q000000981:diagnostic imaging; D000818:Animals; D003907:Dexamethasone; D003940:Diagnostic Techniques, Endocrine / Q000662:veterinary*; D004285:Dogs / Q000097:blood / Q000502:physiology*; D006854:Hydrocortisone / Q000097:blood*; D013997:Time Factors; D014463:Ultrasonography / Q000009:adverse effects* / Q000662:veterinary*
D003907:Dexamethasone; D006854:Hydrocortisone