A Critical Review of the Pharmacokinetics, Pharmacodynamics, and Safety Data of Antibiotics in Avian Species

In avian medicine, the use of antibiotic dosing regimens based on species-specific pharmacological studies is ideal. However, due to a lack of such studies, dose extrapolation, which may cause inefficacy and toxicity, is common practice. Multiple searches were performed using the PubMed and Web of Science databases to extract relevant pharmacological studies performed in exotic avian species. The pharmacokinetics (PK), pharmacodynamics (PD), and safety data of the selected antibiotics (enrofloxacin, marbofloxacin, gentamicin, amikacin, ceftiofur, doxycycline, and amoxicillin/clavulanate) from these studies were reviewed. This review aimed to identify trends amenable for safe inter-species dose extrapolation and provide updated findings on dosing regimens that are safe and efficacious for various exotic avian species. We observed that the half-life of antibiotics appears to be shorter in the common ostrich and that amikacin may be amenable to inter-species dose extrapolation as it is safe and shows little inter-species PK and PD variation. Species-specific enrofloxacin dosing regimens that were not listed in the Exotic Animal Formulary (5th ed.) were found for Caribbean flamingos, African penguins, southern crested caracaras, common ostriches, and greater rheas. Specific dosing regimens recommended for psittacine birds (doxycycline 130 mg/kg medicated water) and ratites (PO doxycycline 2–3.5 mg/kg q12 h, PO enrofloxacin 1.5–2.5 mg/kg q12 h and IM enrofloxacin 5 mg/kg q12 h) in the formulary may not be effective in budgerigars and common ostriches, respectively. Apart from the lack of species-specific pharmacological studies, a lack of multiple dose studies was also noted.

Therapeutics in Herd/Flock Medicine

When treatment is required for a herd/flock health concern, a range of factors must be considered to determine the preferred treatment strategy. If a group treatment strategy is pursued, considerations to optimize the likelihood of safe and effective group treatment include taxon-specific pharmacokinetics/pharmacodynamics, the formulation of prescribed medication, the type and amount of food, the number and type of water sources, enclosure design, size and demography of the group, weather conditions, and health status of individuals in the group. In addition, antimicrobial stewardship principles and relevant legislation/regulation must be at the forefront of decision making.

Overview of Drug Delivery Methods in Exotics, Including Their Anatomic and Physiologic Considerations

Drug delivery to exotic animals may be extrapolated from domestic animals, but some physiologic and anatomic differences complicate treatment administration. Knowing these differences enables one to choose optimal routes for drug delivery. This review provides practitioners with a detailed review of the currently reported methods used for drug delivery of various medications in the most common exotic animal species. Exotic animal peculiarities that are relevant for drug administration are discussed in the text and outlined in tables and boxes to help the reader easily find targeted information.

Anatomy and Disorders of the Beak and Oral Cavity of Birds

Cranial kinesis of the avian beak is complex; particularly in birds with prokinetic beak movement, such as psittacine birds. A number of diseases can result in damage to the bony and soft tissue structures of the beak and can lead to secondary pathology, such as beak deviation, abnormal rhamphothecal growth and wear, and opportunistic infections. A solid understanding of species-specific anatomic variations is essential before attempting rhamphothecal restoration or surgical repair. Many diseases of the oral cavity can appear similar on initial clinical evaluation and therefore warrant appropriate diagnostic testing.