Local tissue damage in cows after intramuscular administration of preparations containing phenylbutazone, flunixin, ketoprofen and metamizole

Tissue irritation after intramuscular injections of 4 nonsteroidal anti-inf lammatory agents was studied in 5 lactating cows. Preparations containing p henylbutazone, flunixin, metamizole (dipyrone) and ketoprofen were investig ated; physiological saline was used as a control substance. Tissue reaction s at the injection sites were examined by palpation and by determining seru m creatine kinase. A kinetic method based on creatine kinase released from the injured muscle tissue was used, which allowed estimation of the amount of damaged muscle. The metamizole preparation clearly provoked signs of pai n in all the cows. After flunixin and phenylbutazone injections slight reac tions were observed, and ketoprofen and saline did not cause any clinical s igns. Some palpatory findings after injections were found for all the prepa rations except saline. Based on serum creatine kinase, the 2 most irritatin g preparations were the ones containing flunixin and phenylbutazone. After injections of these 2 substances, the estimated amount of damaged muscle wa s about 80 grams. The statistical difference between flunixin and phenylbut azone and the other 2 preparations was significant. Physiological saline ha d no effect on serum creatine kinase. For preparations containing phenylbut azone and flunixin, intravenous administration is recommended.