Aims: This study evaluated the effect of anaerobic digestion at 22, 38 and 55 degrees C on odour, coliforms and chlortetracycline (CTC) in swine manure or monensin (MON) in cattle manure. Methods and Results: Swine or cattle were fed the respective growth promotant, manure was collected, and 2-l laboratory methane digesters were established at the various temperatures and sampled over 25 or 28 days. After 21 days, the concentration of CTC in the 22, 38 and 55 degrees C swine digester slurries decreased 7, 80 and 98%, respectively. Coliforms in the 22 degrees C digester slurries were still viable after 25 days; however, they were not detectable in the 38 and 55 degrees C slurries after 3 and 1 days, respectively. After 28 days, the concentration of MON in the 22, 38 and 55 degrees C cattle digester slurries decreased 3, 8 and 27%, respectively. Coliforms in the 22 degrees C cattle digester slurries were still viable after 28 days; however, they were not detectable in the 38 and 55 degrees C slurries after 14 and 1 days, respectively. Conclusions: These studies indicate that anaerobic digestion at 38 or 55 degrees C may be an effective treatment to reduce coliforms and CTC; however, it is not an effective treatment to reduce MON. Significance and Impact of the Study: More studies are needed to determine which pharmaceuticals are susceptible to degradation by a specific manure treatment to prevent negative environmental consequences.