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.
Lennon
Elizabeth M
EM
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Boyle
Tonya E
TE
Hutchins
Rae Grace
RG
Friedenthal
Arit
A
Correa
Maria T
MT
Bissett
Sally A
SA
Moses
Lorra S
LS
Papich
Mark G
MG
Birkenheuer
Adam J
AJ
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