Effects of compounded metronidazole and metronidazole benzoate oral suspensions on food intake in healthy chinchillas (Chinchilla lanigera)

Abstract Background: The administration of metronidazole in chinchillas remains controversial and some sources raise concerns regarding drug-induced anorexia. Therefore, the objective of this study was to evaluate if the oral administration of oral metronidazole has a significant effect on food intake in clinically healthy chinchillas, and if drug-induced reduction of food intake differs between metronidazole and metronidazole benzoate as well as between different concentrations of metronidazole benzoate suspensions. Methods: In a series of randomized, blinded, crossover experiments, the effect of oral administration at 20 mg/kg was evaluated following q12h (for 3 days, n = 12) or q24h (for 5 days, n = 9) dosing using two different drug compounding protocols. Results: Following administration of metronidazole, food intake was significantly reduced within 24 hours of drug administration, regardless of drug formulation type, compounding protocol, or drug volume. Animals which received metronidazole q12h showed a greater reduction in food intake. Variation in metronidazole-induced food intake reduction differed widely between individual chinchillas, with a reduction of > 50 % of food intake reported in 50 % of the animals following q12h administration, and 33 % of animals after q24h administration of metronidazole. The reduction in food intake was self-limiting and return to normal food intake occurred after discontinuation of metronidazole administration. Neurological adverse effects were observed in one animal following q12h administration. Conclusions and Clinical Relevance: The oral administration of metronidazole and metronidazole benzoate at published dosages can result in a marked reduction in food intake, and therefore, this drug should be used cautiously in chinchillas and food intake carefully monitored.