The disposition and effects of 2 formulations of injectable doxycycline administered at 100 mg/kg were investigated to determine if plasma concentrations considered adequate for treating avian chlamydiosis (1 μg/ml) could be safely maintained in 3 species of psittacine birds. Five orange-winged Amazon parrots (Amazona amazonica) that received a commercial doxycycline hyclate formulation (20 mg/ml) intramuscularly achieved maximum plasma doxycycline concentrations of 9.33 ± 0.82 μg/ml and maintained concentrations >1 μg/ml for 5 days. In a second trial, 8 orange-winged Amazon parrots and 8 Goffin's cockatoos (Cacatua goffini) received micronized pharmacist-compounded doxycycline (75 mg/ml IM). In orange-winged Amazon parrots, maximum plasma doxycycline concentration was 2.54 ± 0.38 μg/ml, and concentrations of approximately 0.5 μg/ml were sustained from 24–168 hours. In Goffin's cockatoos, maximum plasma doxycycline concentration was 3.49 ± 0.18 μg/ml, and concentrations >1 μg/ml were maintained for at least 168 hours. In a third trial, groups (n = 4) of orange-winged Amazon parrots, Goffin's cockatoos, and timneh African grey parrots (Psittacus erithacus timneh) received micronized pharmacist-compounded doxycycline (100 mg/ml IM); a separate group of timneh African grey parrots (n = 4) received the same dose subcutaneously. Plasma doxycycline concentrations were lower than in the second trial, and no group achieved 1 μg/ml. After 24 hours, concentrations were sustained at approximately 0.4–0.8 μg/ml in Goffin's cockatoos and at 0.3–0.4 μg/ml in orange-winged Amazon parrots and timneh African grey parrots for at least 20 days. No significant difference was found in doxycycline plasma concentrations in timneh African grey parrots injected subcutaneously as compared with those in parrots injected intramuscularly. Reaction at the injection site was observed in all birds receiving pharmacist-compounded doxycycline, including marked, persistent swelling at the intramuscular injection site and sloughing of skin and scab formation at subcutaneous injection sites. The results of this study show that both the efficacy and the severity of injection-site reactions seen with use of this particular formulation of pharmacist-compounded doxycycline may vary depending on the species treated and particular drug batch.