Objective: To develop an easy and safe method for catheterization and determine the pharmacokinetics of a single dose of enrofloxacin after intracoelomic administration in koi.
Design: Prospective study.
Animals: 20 healthy koi.
Procedure: 6 koi were anesthetized with tricaine methanesulfonate, and a 23-gauge, three-fourths-inch butterfly catheter was inserted into the coelomic cavity and secured. Catheters were flushed daily for 6 days with 0.4 mL of sterile saline (0.9% NaCl) solution containing heparin (100 units of heparin in 250 mL of saline solution) without removing koi from the aquarium. At the end of the sixth day (144 hours), each of the 6 catheterized koi and 6 uncatheterized (control) koi was anesthetized individually. Enrofloxacin (10 mg/kg [4.5 mg/lb]) was administered to catheterized koi via the injection port and to control koi via a 23-gauge needle in the same site as the catheter placement. A pharmacokinetics study was performed on multiple plasma samples to validate the efficiency of the catheter. Reliability of the catheterization method was determined in 8 koi.
Results: All 6 catheters remained patent and effective for the 6 days prior to the start of the pharmacokinetics study. Results for the 2 routes of administration were comparable, and all koi survived the study without any detectable clinical problems.
Conclusions and clinical relevance: An intracoelomic catheter was effective and safe when maintained in koi for at least 6 days. This would be highly beneficial for veterinarians, clients, and fish, especially when intracoelomic administration of a drug would require daily or more frequent dosing.