Nectarivorous birds are those that rely predominantly on the products of flowering trees and shrubs for food. Australian avian nectarivores include honeyeaters of the family Meliphagidae and lorikeets and swift parrots (Lathamus discolor) of the family Psittacidae. Nectar is a sugar-rich, liquid food source that provides abundant amounts of energy for birds that are able to harvest it. However, it contains very low levels of amino acids, vitamins, and trace minerals necessary for avian maintenance, growth, and reproduction. Therefore, birds classified as nectarivores need to forage for other food resources. Manna, honeydew, and lerp are common food sources for a variety of honeyeaters and nectarivorous parrots; these foods are high in carbohydrates and low in protein, similar to nectar. Pollen protoplasm is composed of highly digestible protein and contains a diverse amino acid profile; however, only 3 Australian species of psittacine birds have been recorded engaging in active pollen harvesting. Insects are thought to be the main source of protein for nectarivores. Nectarivorous birds have developed a variety of morphologic and physiologic adaptations. Morphologic adaptations to nectarivory include changes in body size, plumage, beak and tongue structure, and the alimentary organs. The physiology of nectarivory is still poorly understood, but there are indications that adaptations may include lowered metabolic rates, lowered protein requirements, and changes in digestive and renal physiology. Considerable work is needed to illuminate the specific nutritional requirements of nectarivores for maintenance, growth, and reproduction.

Little is known about the energy requirements of pet birds. Because animals generally eat to meet energy requirements, the nutrient content of a diet must be balanced with the energy content. To formulate balanced diets for a range of bird species, both the energy needs of the relevant bird species and the energy content of the diet must be calculated. The most practical way of understanding the energy requirements of pet birds is by studying their daily energy expenditure. Factors affecting energy requirements are body size, activity patterns, environmental temperature, plumage cover, age, and physiologic state. Energy costs of maintenance are directly related to the lean body mass and the relative size of the different organs, because these are the tissues that actively use oxygen. Activity patterns also have a considerable impact; the difference between sitting and standing can affect the daily energy expenditure by as much as 42%. There are a variety of published allometric equations for determining avian energy requirements, but those derived from fasted species are inappropriate. For companion birds, equations derived for the particular body-weight range of the avian species in question are the most applicable. Two equations are recommended: one for calculating the energy requirements of avian species less than 100 g, and the second for avian species whose body weights are in the range 100–1500 g.

Serologic assays and protein electrophoresis have been used to aid diagnosis of aspergillosis in several species of captive birds, but sensitivities of these tests have not been established in psittacine birds. In 7 psittacine birds with respiratory tract aspergillosis confirmed by cytologic or histopathologic analysis, 1 bird had a positive Aspergillus antibody enzyme-linked immunosorbent assay (ELISA) titer, and 3 birds had positive Aspergillus antigen ELISA titers. In 3 birds, plasma protein electrophoretograms showed moderately to markedly increased β-globulin concentrations. Six birds had moderately to markedly decreased plasma albumin to globulin ratios. On the basis of this information, the antibody and antigen ELISA tests used in this study do not appear to be highly sensitive screening tests for aspergillosis in psittacine birds. The changes in plasma protein electrophoretograms were the more consistent findings in birds with aspergillosis, but results could also be normal in affected birds.

In the face of increasing bacterial drug resistance because of β-lactamase production, many microbial infections can be treated effectively by combining clavulanic acid with amoxicillin. Judicious drug use that includes defining the optimum dosage is important to control development of resistance to this drug combination. In this study, amoxicillin and clavulanic acid were administered to blue-fronted Amazon parrots (Amazona aestiva aestiva) in a multiple dosing trial. Birds were gavaged with 125 mg/kg of the drug combination at 0800, 1600, and 2200 hours on days 1–5. The half-lives of amoxicillin and clavulanic acid were similar to those in humans; however, the area under the curve was increased in the parrots compared with humans. These results suggest that this drug combination, at this dosing interval, achieves levels that may be effective against many bacterial species.

Twelve adult female saker falcons developed reduced appetite, progressive weight loss, and unilateral or bilateral sinusitis. Nodular white or yellow caseous lesions were visible on the oropharynx and tongue of all birds. One falcon had 2 caseous masses on either side of the tracheobronchial syrinx, resulting in severe tracheal stenosis. All 12 birds had a history of mild to moderate trichomonal infections 3–4 weeks before examination. In all birds, bacterial culture of samples from these masses yielded pure growths of Pseudomonas aeruginosa. The birds were treated with a combination of piperacillin (100 mg/kg) and tobramycin (10 mg/kg) administered intramuscularly q12h for 7 days. Oropharyngeal lesions were debrided, and the oral cavity of each bird was sprayed with a 1% povidone iodine mouthwash preparation. In birds with unilateral or bilateral sinusitis, a solution of 0.2 ml of a 5% chlorhexidine gluconate preparation diluted to 20 ml with sterile saline was used to flush the affected sinus q12h for 3–5 days. Tracheal masses in the 1 falcon were removed by curettage during tracheoscopy. Oropharyngeal lesions in all birds were completely resolved within 8–18 days of treatment. Trichomoniasis coupled with stress during the training and hunting seasons may have predisposed these falcons to infection with P aeruginosa.

Palatine bone luxation was diagnosed in a blue-and-gold macaw (Ara ararauna) on the basis of history, physical examination, and radiographic findings. The bird had a history of recent head trauma and subsequent inability to prehend food. Physical examination findings were normal except for a hyperextended maxillary beak. Simple reduction of the luxation was unsuccessful. Detailed analysis of radiographs, anatomic descriptions, and cadaver dissections revealed that the hyperextended maxillary beak was caused by the dorsal luxation of the palatine bones. The luxation was surgically reduced by introducing an intramedullary pin transversely across the infraorbital sinus dorsal to the palatine bones. The maxillary beak was then hyperextended while the luxated palatine bones were concurrently reduced ventrally to their anatomic position. The luxation was stabilized by passing absorbable suture around the suborbital arch and jugal bones bilaterally. Reduction and stabilization was successful; however, the macaw died of anesthetic complications after surgery.