Use of basal serum or plasma cortisol concentrations to rule out a diagnosis of hypoadrenocorticism in dogs: 123 cases (2000-2005).
OBJECTIVE
To determine whether basal serum or plasma cortisol concentration can be used as a screening test to rule out hypoadrenocorticism in dogs.


METHODS
Retrospective case-control study.


METHODS
110 dogs with nonadrenal gland illnesses and 13 dogs with hypoadrenocorticism.


METHODS
Sensitivity and specificity of basal serum or plasma cortisol concentrations of either <or= 1 microg/dL or <or= 2 microg/dL to detect dogs with hypoadrenocorticism were estimated by use of the ACTH stimulation test as the gold standard.


RESULTS
Basal cortisol concentrations of <or= 1 microg/dL had excellent sensitivity (100%) and specificity (98.2%) for detecting dogs with hypoadrenocorticism. For basal cortisol concentrations of <or= 2 microg/dL, sensitivity was 100% but specificity was 78.2%.


CONCLUSIONS
On the basis of sensitivity and specificity, basal serum or plasma cortisol concentrations had high negative predictive values over a wide range of prevalence rates and can be used to rule out a diagnosis of hypoadrenocorticism. Dogs with basal cortisol concentrations > 2 microg/dL that are not receiving corticosteroids, mitotane, or ketoconazole are highly unlikely to have hypoadrenocorticism. However, if the basal cortisol concentration is <or= 2 microg/dL, little to no information regarding adrenal gland function can be obtained and an ACTH stimulation test should be performed.
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Elizabeth M
EM
Lennon
Tonya E
TE
Boyle
Rae Grace
RG
Hutchins
Arit
A
Friedenthal
Maria T
MT
Correa
Sally A
SA
Bissett
Lorra S
LS
Moses
Mark G
MG
Papich
Adam J
AJ
Birkenheuer
D000311:Adrenal Glands / Q000473:pathology*; D000309:Adrenal Insufficiency / Q000097:blood / Q000175:diagnosis / Q000235:genetics / Q000662:veterinary*; D000818:Animals; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D004285:Dogs; D005260:Female; D020022:Genetic Predisposition to Disease; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D009674:Nova Scotia / Q000453:epidemiology; D010375:Pedigree; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D006854:Hydrocortisone