Comparing treatment methods of canine hypoadrenocorticism

Management of canine hypoadrenocorticism relies on supplementation of glucocorticoids and mineralocorticoids. Although previous studies show success of both a steroid with combined activity (fludrocortisone) and steroids with separate activities (DOCP with prednisolone) in the management of canine hypoadrenocorticism, the two treatment methods had never been prospectively compared. The objective of this clinical trial was to compare fludrocortisone to DOCP with prednisolone for the management of canine hypoadrenocorticism in stable patients. A prospective, randomised, cross-over, non-blinded, non-inferiority trial was conducted. Patients were randomised into two groups: Group A received three months of treatment with the interventional product (DOCP and prednisolone) followed by three months of the control product (fludrocortisone) whilst Group B received three months of the control product followed by three months of the interventional product. Primary outcome measures were electrolyte concentrations and clinical signs at the end of each phase of the trial. Secondary outcome measures included plasma renin activity, endogenous ACTH, blood pressure and routine haematology/biochemistry results. No dogs had clinical signs of hypoadrenocorticism or hyponatraemia/hyperkalaemia at the end of the DOCP phase of the trial. Three dogs however were hyponatraemic at the end of the fludrocortisone phase of the trial, although no patients were hyperkalaemic or showed clinical signs of hypoadrenocorticism. The blood pressure was significantly higher (Paired T test; P=0.006) at the end of the DOCP phase (mean 161mmHg; SD 26.3) than at the end of the fludrocortisone phase (mean 147mmHg; SD 26.2). The neutrophil count was significantly higher (Paired T test; P=0.009) at the end of the DOCP phase (mean 7.49x10^9/L; SD 3.1) compared to the fludrocortisone phase (mean 5.81x10^9/L; SD 2.31). The urea was significantly lower (Wilcoxon Signed Rank test; P <0.001) at the end of the DOCP phase (median 5.3mmol/L; 2.9-11.7) compared to the end of the fludrocortisone phase (median 7.4mmol/L; 3.8-17.2). The creatinine was also significantly lower (Paired T test; P=0.001) at the end of the DOCP phase (mean 96umol/L; 19.2) compared to the fludrocortisone phase (mean 109umol/L 28.9). The ACTH and renin concentrations were significantly lower at the end of the DOCP phase compared to the fludrocortisone phase (Wilcoxon Signed Rank test; both P