A retrospective study of hydrocortisone continuous rate infusion compared with administration of dexamethasone boluses in dogs with adrenal crisis.

Background: Evidence indicating the optimal treatment protocol for dogs in adrenal crisis is lacking.

Objectives: Compare outcomes of dogs presented in adrenal crisis treated with either hydrocortisone (HC) continuous rate infusion (CRI) or intermittent dexamethasone (DEX) administration.

Animals: Thirty-nine client-owned dogs.

Methods: Multi-institutional retrospective observational study (July 2016-May 2022) including dogs diagnosed with adrenal crisis and with available sequential blood work during hospitalization. Dogs were excluded if already on treatment with exogenous corticosteroids. Outcomes assessed included duration of hospitalization, survival, number of repeat measurements of electrolyte concentrations, and time to normalization of electrolyte and acid-base status.

Results: No significant difference was found between the groups for hospitalization time (P = .41; HC median [range] 48 h [19-105 h]; DEX 57 h [17-167 h]) nor case fatality rate 2/28 in the DEX group and 0/11 in the HC group (P = 1), nor in number of measurements of electrolyte concentrations (P = .90; HC 4 [2-10]; DEX 4.5 [2-15]). No significant differences were found between the 2 treatment groups in time to normalization of serum Na (P = .30; HC 33 h [7-66 h]; DEX 16 h [1.5-48 h]), K (P = .92; HC 17 h [4-48 h]; DEX 16 h [1.25-60 h]) or Na/K ratio (P = .08; HC 17 h [8-48 h]; DEX 26 h [1.5-60 h]).

Conclusions: This study detected no difference in outcomes for dogs in adrenal crisis treated with either DEX boluses or HC CRIs.