CORRELATION OF INJECTION SITE DAMAGE AND SERUM CREATINE-KINASE ACTIVITY IN TURKEYS FOLLOWING INTRAMUSCULAR AND SUBCUTANEOUS ADMINISTRATION OF NORFLOXACIN NICOTINATE

Turkeys were given an intramuscular (Wi) or subcutaneous (SC) injectio n of an aqueous solution of norfloxacin nicotinate (NFN) and some were also given an IM injection of saline. Serum creatine kinase (CK) acti vity was measured immediately before and at intervals after treatment, and turkeys were also killed at intervals to assess the extent and du ration of local tissue damage at the injection site. IM injection of s aline and SC injection of NFN resulted in minimal damage. At 8 h post- treatment serum CK activity was two to three rimes greater than the pr etreatment value, but was back to the pretreatment level by 72 h. LM i njection of NFN resulted in a level of CK activity that was 9.83 +/- 5 .16 (mean +/- standard deviation) times greater than pretreatment valu e, and also swelling and haemorrhage at the injection site and microsc opic changes characteristic of severe irritation. Histological evidenc e of muscle repair was delayed for 5 days after IM NFN administration although serum CK activity has returned to pretreatment levels by this time. These results suggest that the rise in serum CK activity in the turkeys correlated well with the extent of muscle tissue damage, but poorly with its duration.