Lower initial dose desoxycorticosterone pivalate for treatment of canine primary hypoadrenocorticism.

OBJECTIVE: To evaluate the efficacy of initial doses of desoxycorticosterone pivalate (DOCP) that are lower and less expensive than the presently recommended initial dose of 2.2 mg/kg for treating dogs with primary hypoadrenocorticism.
METHODS: A retrospective study was performed on 49 dogs with primary hypoadrenocorticism, including 36 with initial DOCP doses less than 2.2 mg/kg. Medical records were reviewed for clinical data. All study dogs were followed up with telephone calls to owners or veterinarians to determine the date of death or last follow-up. Data were analysed to investigate relationships between initial DOCP dose and survival and serum Na, K and their ratio.
RESULTS: Regardless of their initial DOCP dose, none of the dogs developed uncontrolled hypoadrenocorticism or severe electrolyte abnormalities or clinical problems that would have made an increase in the DOCP dose necessary. Over time, most dogs had a decrease in their DOCP dose in mg/kg, because of weight gain during treatment. No statistically significant relationships were found between initial DOCP dose and survival or post-treatment serum Na, K or Na : K, with the exception of one statistically significant result that suggested lower efficacy for higher doses.
CONCLUSION: Initial DOCP doses less than 2.2 mg/kg may be effective in controlling serum electrolyte concentrations in dogs with primary hypoadrenocorticism without adversely affecting survival. If confirmed by additional research, these findings would enable practitioners to reduce the cost of DOCP treatment by using lower initial doses, potentially saving the lives of dogs that would otherwise be euthanased because of treatment expense.