In vivo quantification of muscle damage in dogs after intramuscular administration of drugs.

Intramuscular injections of a vitamin B preparation, imidocarb, imidocarb+lidocaine, and a preparation of salts of fatty acids produced significant increases in plasma creatine kinase activity in groups of five to six dogs. Activities peaked between 3 and 8 h, and were as high as 23 times base values with the fatty acid salts preparation. Quantification of the equivalent muscle damage gave means of 0.04, 0.25, 0.23 and 0.30 g kg-1 body weight, respectively, for each of the above preparations.