Carrageenan-induced inflammation elicits behavioral changes in cockatiels (Nymphicus hollandicus) for potential pain scale development

Abstract

Abstract OBJECTIVE To evaluate behaviors associated with inflammatory pain induced by carrageenan injection in the cockatiel and determine interobserver agreement. ANIMALS 16 adult cockatiels. METHODS Cockatiels were randomly assigned as either treatment (carrageenan injection) or control (sham injection) group. The treatment group received a subcutaneous injection of 0.05 mL of a 1% lambda carrageenan solution into the left footpad. Following treatment or control procedures, all cockatiels were video recorded individually for 9.5 hours. Ten minutes of video at each of 11 time points postinjection and/or handling were evaluated by 3 different observers. Twenty-five behaviors within 6 categories (resting, locomotion, maintenance, intake, interaction with environment, and limb and body posture) were assessed, in addition to crest position and mentation. Differences in individual behaviors tallies were assessed using serial Wilcoxon sum rank tests. Interobserver agreement was assessed using an intraclass correlation coefficient for a 2-way design for consistency among multiple observers. RESULTS Treatment cockatiels exhibited significantly increased focal preening (q = .023) and increased burst preening (q = .036), while control cockatiels spent significantly more time in an upright stance (q = .036). Although the remainder of behaviors observed were not statistically significant between groups, additional variables of interest seen more frequently in treatment cockatiels included non–weight-bearing stance, holding of the body low, and being nonvigilant. The level of agreement between observers was variable based on the specific behaviors; nevertheless, the dynamic behaviors were substantial to strong. CLINICAL RELEVANCE Carrageenan-induced inflammation-associated behaviors may be valuable in developing a pain scale and evaluating mild inflammatory pain in small psittacine species.