اثرات مقدار درمانی اکسی تتراسیکلین بر کلسیم، منیزیم و پاراتورمون گوسفند

The aim of this study was to evaluate the the effects of therapeutic dose of oxytetracycline on magnesium, calcium and parathormone in sheep. five female sheep were used for this study. the animals were dewormed by albendazole orally and ivermectin subcutaneously. prior to injection of the oxytetracycline (0h), blood, urine and fecal samples were taken to determine base line values of calcium, phosphorous and parathormone. oxytetracycline was administrated intravenously (jugular vein) at a dose rate of 10 mg/kg body weight with 100 ml normal saline solutions every 24 hours until five days. to evaluate the effects of oxytetracycline on blood, urine and fecal parameters, samples were collected based on 1/2 half life of oxytetracycline (4 hours and 45 minutes after injection of oxytetracycline) and delivered to laboratory. blood calcium decreased at 48, 96 and 120 hours, blood phosphorous increased without significant changes, urine calcium and phosphorous increased significantly at 72 and 120 hours respectively. blood parathormone levels showed a general elevation over the course of the study but significant increase occurred at 72 and 96 hours after injection of oxytetracycline. blood magnesium decreased significantly at 120 hours after injection of oxytetracycline and urine magnesium increased significantly at 48 hours post injection of oxytetracycline. fecal calcium declined significantly at 72 hours after injection of oxytetracycline and fecal phosphorous decreased without detectable significant changes. therefore, the usage of oxytetracycline in animals that are at risk of hypocalcaemia is contraindicated. as a result, oxytetracycline leads to hypercalciuria, hypermagnesauria, hypocalemia and hypomagnesaemia in animals.