Effects of Capromorelin, Mirtazapine, and Cyproheptadine on Food Intake in Budgerigars (Melopsittacus undulatus)

These studies aimed to evaluate the appetite-stimulating effects of capromorelin, cyproheptadine, and mirtazapine in budgerigars (<i>Melopsittacus undulatus</i>). The effects of a single oral dose of capromorelin (10 and 40 mg/kg), cyproheptadine (0.5 and 2.5 mg/kg), and mirtazapine (1 and 5 mg/kg) on food intake in budgerigars (n = 12 per study) were evaluated in 3 separate blinded, randomized, placebo-controlled complete crossover studies. Food intake was quantified in hourly intervals between 1 and 8 hours after administration and in a 4-hour interval between 8 and 12 hours. Both doses of capromorelin significantly increased mean food intake in the first 12 hours after administration (10 mg/kg: 66 ± 39 g/kg; 40 mg/kg: 71 ± 40 g/kg) compared with the control treatment (46 ± 30 g/kg). Administration at 10 and 40 mg/kg capromorelin resulted in a 1.5-fold increase (interval: 0.4-9) and 1.7-fold increase (interval: 0.7-5.5) in food intake, respectively. Productive and nonproductive regurgitation after administration of capromorelin at 40 mg/kg occurred in 92% of birds within 1 hour of administration, compared with 42% of birds and 25% of birds who regurgitated in the 10 mg/kg and control treatments, respectively. Cyproheptadine and mirtazapine did not have a measurable appetite-stimulating effect in this study, and no significant adverse effects were recorded.