Analgesic Efficacy of Tramadol Compared With Meloxicam in Ducks (Cairina moschata domestica) Evaluated by Ground-Reactive Forces

Treatment of Pain in Birds

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and/or other drugs like gabapentin, amantadine, and cannabinoids, acting at different points in the nociceptive system thereby helping to provide greater pain relief while reducing the risk of adverse effects when combined.

A Critical Review of the Pharmacokinetics and Pharmacodynamics of Opioid Medications Used in Avian Patients

Opioid drugs are used to manage moderate to severe pain in mammals and avian species. In dosing opioids for a particular species, it is optimal to use dosing regimens based on pharmacokinetics or pharmacodynamics studies conducted in the same species as variability in the physiology among different species may result in differences in drug pharmacokinetics and pharmacodynamics. Unfortunately, dosing regimens are typically extrapolated from closely related avian species or even mammals, which is unideal. Therefore, this critical review aims to collate and evaluate the dosing regimens of selected opioids: tramadol, hydromorphone, buprenorphine, butorphanol, and fentanyl, in avian species and its related safety, efficacy and pharmacokinetic data. Our review found specific dosing regimens not described in the Exotic Animal Formulary for tramadol used in Indian Peafowl (Pavo cristatus), Muscovy Duck (Cairina moschata) and Hispaniolan Parrot (Amazona ventralis); hydromorphone used in Orange-winged Parrot (Amazona amazonica); buprenorphine used in Cockatiel (Nymphicus hollandicus), American Kestrel (Falco sparverius) and Grey Parrot (Psittacus erithacus); and butorphanol used in Hispaniolan Parrot (Amazona ventralis), Broiler Chicken and Indian Peafowl (Pavo cristatus). Cockatiel appeared to not experience analgesic effects for hydromorphone and buprenorphine, and American Kestrel exhibited sex-dependent responses to opioids. The selected opioids were observed to be generally safe, with adverse effects being dose-dependent.

Backyard Poultry and Waterfowl Sedation and Anesthesia

The popularity of backyard poultry (chickens, turkey, guinea fowl) and waterfowl (ducks and geese) is increasing in the United States, and these animals frequently present for veterinary care. Like other birds, these species have unique anatomy that should be clinically considered before anesthesia. A balanced approach to an injectable, inhalational, or combination anesthesia protocol must be taken to ensure a safe outcome for the patient and to achieve the procedural needs. A well-informed clinician may use both sedation and general anesthesia to care for backyard bird patients in practice.

OBJECTIVE GAIT ANALYSIS IN HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI) USING A PRESSURE-SENSITIVE WALKWAY

Assessment of pododermatitis, osteoarthritis, and other causes of lameness in penguins can be challenging. Subjective gait analysis using visual observation and response to analgesic therapy can be affected by observer variation and caregiver placebo bias. A pressure-sensitive walkway (PSW), however, allows for objective gait analysis and assessment of analgesic therapeutic response. In this study, a 3-m-long PSW was used to analyze gait in 21 adult Humboldt penguins (Spheniscus humboldti). Medical record reviews and comprehensive examinations were performed on all penguins; five penguins were considered abnormal, with either right-sided (n = 3) or bilateral historical lameness-causing disease (n = 2) and were analyzed separately from the normal data set. All penguins walked across the PSW four times and gait parameters (step and stride distances and velocities, maximum force, impulse, and peak pressure) were calculated for each foot in each penguin. Statistical comparisons were made between right and left feet, sexes, and normal and abnormal penguins for each gait parameter. Among normal penguins, there were no significant differences between feet or sex. Left step width was shorter in abnormal penguins than that of normal penguins. Study results established baseline values for Humboldt penguins. This will allow objective monitoring of progression and response to therapy in penguin lameness cases, both current and future. The data also provide a foundation to compare gait parameters with other penguin populations and species.

Evaluation of a pressure sensitive walkway for objective gait analysis in normal and arthritic domestic ducks (Cairina moschata domestica)

Objective gait evaluation with a pressure sensitive walkway (PSW) has been used to assess welfare of poultry and to assess lameness and response to therapy in domestic mammals. Objective gait analysis of birds with lameness due to pododermatitis, osteoarthritis, and other common diseases could provide non-biased assessment and therapeutic monitoring for zoo clinicians. The objective of this study was to evaluate the use of a PSW for objective gait analysis in normal domestic ducks (Cairina moschata domestica) and those with experimentally induced arthritis. Eighteen healthy adult ducks walked across the PSW four times in each experiment at each time point. For experiment 1, gait parameters (step and stride distances and velocities, maximum force, impulse, and peak pressure) were calculated for each foot in each duck (time 0). For experiment 2, six of these ducks were randomly selected, anesthetized, and administered a unilateral intra-tarsal injection of monosodium urate solution to induce arthritis. Serial PSW trials were repeated at 1, 2, 3, 4, 8, and 24 hours post-injection. Gait parameters were calculated and compared at each time point, including baseline at time 0. Among the normal ducks, there were no significant differences between right and left feet for any gait parameter. Maximum force and impulse were significantly lower for the affected limb at the 3- and 4-hour time points in ducks with unilateral induced arthritis. This asymmetry was resolved by 8 hours post injection. This PSW transient arthritis model allows for objective assessment of lameness in domestic ducks with maximum force and impulse serving as the most sensitive gait parameters for lameness detection. This method has potential as a model to assess analgesic efficacy for zoo-housed waterfowl and other avian species.