The Educated Guess: Determining Drug Doses in Exotic Animals Using Evidence-Based Medicine

Lack of species-specific pharmacokinetic and pharmacodynamic data is a challenge for pharmaceutical and dose selection. If available, dose extrapolation can be accomplished via basic equations. If unavailable, several methods have been described. Linear scaling uses an established milligrams per kilograms dose based on weight. This does not allow for differences in species drug metabolism, sometimes resulting in toxicity. Allometric scaling correlates body weight and metabolic rate but fails for drugs with significant hepatic metabolism and cannot be extrapolated to avians or reptiles. Evidence-based veterinary medicine for dose design based on species similarity is discussed, considering physiologic differences between classes.