This question was forwarded to me related to the webinar on New Research Insights Into Canine Addison's Disease ...
If a dog is being treated or has recently been treated with steroids (e.g. for allergies or another medical problem etc.) can this affect testing for Addison’s? If so, what is recommended in these situations?
Yes, absolutely - recent steroid administration will affect testing for Addison's disease. The hypothalamic pituitary adrenal (HPA) axis recovers fairly quickly after short term (less than 2 weeks) steroid use. However, the optimal time to test after stopping steroids is unknown, especially after long term use. In people, the earliest that HPA axis recovery occurs is about 4 weeks after long term steroid use.
Recommendations would have to be on a case by case basis but I would tailor testing based on how long and how recently the steroids were administered. If the ACTH stim test comes back normal (assuming that no Prednisone, Prednisolone, methylpred or hydrocortisone have been administered in the 24 hours before the test - as these will cross react ("show up") up in the cortisol assay) then Addison's is ruled out. However, if the ACTH stim is abnormal after steroid administration, this test cannot distinguish iatrogenic from spontaneous Addison's.
