Intramuscular administration of a low dose of ACTH for ACTH stimulation testing in dogs.
OBJECTIVE
To compare adrenal gland stimulation achieved following administration of cosyntropin (5 microg/kg [2.3 microg/lb]) IM versus IV in healthy dogs and dogs with hyperadrenocorticism.


METHODS
Clinical trial. Animals-9 healthy dogs and 9 dogs with hyperadrenocorticism.


METHODS
In both groups, ACTH stimulation was performed twice. Healthy dogs were randomly assigned to receive cosyntropin IM or IV first, but all dogs with hyperadrenocorticism received cosyntropin IV first. In healthy dogs, serum cortisol concentration was measured before (baseline) and 30, 60, 90, and 120 minutes after cosyntropin administration. In dogs with hyperadrenocorticism, serum cortisol concentration was measured before and 60 minutes after cosyntropin administration.


RESULTS
In the healthy dogs, serum cortisol concentration increased significantly after administration of cosyntropin, regardless of route of administration, and serum cortisol concentrations after IM administration were not significantly different from concentrations after IV administration. For both routes of administration, serum cortisol concentration peaked 60 or 90 minutes after cosyntropin administration. In dogs with hyperadrenocorticism, serum cortisol concentration was significantly increased 60 minutes after cosyntropin administration, compared with baseline concentration, and concentrations after IM administration were not significantly different from concentrations after IV administration.


CONCLUSIONS
Results suggest that in healthy dogs and dogs with hyperadrenocorticism, administration of cosyntropin at a dose of 5 microg/kg, IV or IM, resulted in equivalent adrenal gland stimulation.
Behrend
Ellen N
EN
Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, AL 36849, USA.
Kemppainen
Robert J
RJ
Bruyette
David S
DS
Busch
Katherine A
KA
Lee
Hollie P
HP
D000304:Adrenal Cortex Function Tests / Q000379:methods / Q000662:veterinary*; D000308:Adrenocortical Hyperfunction / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000493:pharmacokinetics; D000818:Animals; D019540:Area Under Curve; D003366:Cosyntropin / Q000097:blood / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis*; D004285:Dogs; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D007273:Injections, Intramuscular / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male
D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone