Calcitriol concentrations increased during treatment, but PTH was not measured.141 In a later study in dogs with experimentally induced renal secondary HPTH, an oral calcitriol dosage of 6.6 ng/kg/day resulted in suppression of PTH secretion within 30 days in most dogs, but hypercalcemia occasionally developed at this dose.142. The gene discussed is PTH; the disease is Hypercalcemia.