Vasectomy is done to produce infertility by surgically removing a portion of the ductus deferens from both testicles. In birds, vasectomy can be done internally or externally. Internal vasectomy is performed by severing and removing a section of the ductus deferens through bilateral celiotomy or by endoscopic-guided techniques. Vasectomy can be done externally using standard surgical procedures in those species possessing seminal glomera. In this review, the surgical techniques used to perform vasectomy in birds and the implications and applications of each technique are discussed.

Vascular diseases in birds are not uncommon, according to findings from postmortem surveys. Although atherosclerosis affecting psittacine birds appears overrepresented, some degenerative, infectious, neoplastic, and congenital vascular diseases may also occur. A variety of imaging diagnostic tools may be used to evaluate the avian vascular system, such as conventional radiography, fluoroscopy, rigid endoscopy, computed tomography, angiography, transcoelomic, and transesophageal ultrasound examination. The wide array of current diagnostic imaging tools offers the clinician capabilities to investigate avian cardiovascular abnormalities. Further research in this domain and constant efforts to apply several, and newer, vascular imaging modalities in clinical cases are needed to expand our avian cardiovascular knowledge base. The ability to diagnose vascular pathologic processes in small avian patients may be improved by recent developments in diagnostic imaging technology.

Collection of exhaled breath condensate (EBC) and the measurement of inflammatory markers contained therein (eg, hydrogen peroxide [H₂O₂], leukotriene B₄ [LTB₄], and pH) have been reported to be noninvasive tools for the investigation of respiratory disease in various species. In this study, the EBC of clinically healthy psittacine birds (n  =  15) and psittacine birds with respiratory tract disease (n  =  19) was examined, and inflammatory markers contained in the EBC were analyzed and compared. Awake birds were placed in an acrylic container from which the outflow passed through a condensation system that collected the EBC. All samples were analyzed for pH, H₂O₂, and LTB₄. The mean values for each of these components, as well as the mean volume of the total EBC, measured from the apparently healthy birds did not differ significantly from those measured in birds with signs of respiratory tract disease. However, LTB₄ in the EBC of diseased birds was higher than that of the apparently healthy birds and showed a trend toward significance. The study demonstrated the establishment of a standardized method for collecting and analyzing EBC in psittacine birds and a measurement protocol for pH, H₂O₂, and LTB₄.

Avian polyomavirus (APV) causes a range of disease syndromes in psittacine birds, from acute fatal disease to subclinical infections, depending on age, species, and other unidentified risk factors. To determine the prevalence of APV-specific antibodies in a captive population of Spix's macaws (Cyanopsitta spixii) in Quatar, 54 birds were tested by blocking enzyme-linked immunosorbent assay. A prevalence of 48.1% for APV antibodies, which indicates viral exposure, was found. Of 36 Spix's macaws that were serially tested over a period of 4 years, 50.0% were consistently positive, 36.1% were consistently negative, 5.5% had permanently declining antibody levels, and 2.8% showed variable results. By using polymerase chain reaction testing on whole blood samples, an apparent viremia was detected in 1 of 44 birds (2.3%), although contamination provides a likely explanation for this isolated positive result in a hand-reared chick. The white blood cell count was significantly higher in antibody-positive birds compared with antibody-negative birds (P < .05). Because antibody-positive and antibody-negative birds were housed together without a change in their respective antibody status, transmission of APV within the adult breeding population appeared to be a rare event.

The order Passeriformes comprises the largest number of families and species of birds of any avian order. Brazil is rich in passerine birds, which are a common victim of wildlife trafficking in Brazil. Annually, many birds die as a consequence of illegal trade. To investigate the occurrence of the principle diseases and to identify the main causes of death in smuggled passerine birds, the cause of death was evaluated in 360 passerine birds confiscated within the city of São Paulo, Brazil. Causes of death were determined by anatomopathologic and microbiologic studies. Infectious diseases were the cause of death of most birds, which corresponded to 78.6% of cases. The most common infectious diseases were poxvirus infection, aspergillosis, and coccidiosis. Although the etiologic agents of these diseases can coexist asymptomatically within hosts, once the host's immunity is compromised, the pathogen multiplies quickly and causes disease. The results of this study may help to improve the care of passerine birds in captivity and increase the survival rate of confiscated birds. Results may also be useful for in situ conservation programs that investigate the reintroduction of confiscated species or captive birds.

Aflatoxin B₁ is a common hepatotoxin in birds. The goal of this study was to establish an acute model for hepatotoxicosis and decreased hepatic function in the white Carneaux pigeon (Columba livia) via oral administration of this mycotoxin. Aflatoxin B₁ was orally administered at a dose of 3 mg/kg dissolved in dimethyl sulfoxide to 3 groups of pigeons every 24 hours for 2, 4, and 6 consecutive days, respectively. Diagnostic modalities used to evaluate hepatic damage and impaired hepatic function pre- and postaflatoxin administration included liver enzyme activity, bile acid levels, scintigraphy, and histopathologic evaluation of liver biopsy specimens. Deaths occurred in all groups, increasing with the number of consecutive days the aflatoxin B₁ was dosed. Significant histopathologic lesions were seen on evaluation of hepatic tissue from each group after accumulated aflatoxin exposure (P < .05); therefore, an oral aflatoxin B₁ dose of 3 mg/kg given for 2 consecutive days was selected for the purpose of inducing acute hepatic damage while minimizing mortality. However, although increased liver enzyme activity indicated hepatocellular damage at this dosage, bile acids testing and hepatobiliary scintigraphy did not show significantly decreased hepatic function.

To establish reference values for the cardiac size during radiographic examination in 4 species of Falconiformes used for falconry, lateral and ventrodorsal radiographs were examined from healthy birds of 4 species: Harris' hawks (Parabuteo unicinctus) (n  =  48), peregrine falcons (Falco peregrinus) (n  =  35), saker falcons (Falco cherrug) (n  =  19), and lanner falcons (Falco biarmicus) (n  =  13). On the lateral view, ratios between the length of the heart from base to apex and total length of the carina were calculated. On the ventrodorsal view, ratios between the width of the heart at its widest point and the distance between the ribs at the same level and between the width of the coracoid immediately caudal to the humeral articular surface in the shoulder joint and width of the heart and the distance between the ribs were calculated. No differences were found between species in the ratio of length of the heart/length of the carina. The ratios of width of the heart/distance between ribs and width of the heart/coracoid width differed between hawks and falcons but did not differ between the 3 falcon species.

To investigate the prevalence of Cryptococcus in droppings from captive birds in Chile, dry droppings from 113 captive birds of various species were cultured for Cryptococcus neoformans. The yeast was recovered from 17 of the 113 samples (15% [95% confidence intervals, 8.4%–21.6%]). Other yeast organisms recovered from psittacine bird droppings were Cryptococcus albidus and Cryptococcus uniguttulatus. Secreted phospholipase has been proposed as a virulence determinant in C neoformans. Phospholipase production by the egg yolk plate method, and in vitro susceptibility to fluconazole by using the disk diffusion test were performed on 17 C neoformans isolates. Two of the 17 strains (11.7%) did not produce phospholipase. Two (11.7%) were resistant to fluconazole, and 5 of 17 (29.4%) were susceptible dose-dependent. The Cryptococcus species isolated from droppings from captive birds could be potential pathogens in humans.

The World Wide Web – it has broadened our ability to communicate beyond ways imaginable. In our veterinary practices, it has changed the way we interact with our colleagues. We can now refer cases to specialists with the click of a mouse. We can share any number of radiologic images with the stroke of a keyboard. We can attend continuing education meetings without ever leaving our workplaces. We can even order hospital supplies and equipment without even having to speak to a salesperson. The Internet has also changed our dynamics with clients. On the one hand, we can now share information with clients without their having to bring their pets into the hospital or even without having to speak with them on the telephone. We can provide clients with reams of educational material or with their pet's medical records without ever having to print a page. On the other hand, the Internet has shattered the image of the veterinarian as the expert in pet care; clients can now surf the Web and diagnose their pet's condition without ever even seeing their veterinarian. And if they do actually take their sick pet to the veterinarian, they often have researched their pet's clinical signs and have a tentative diagnosis and possible treatment plan in mind before they walk through the clinic door. So, is the Internet the veterinarian's friend or foe? To answer this question, I have invited 6 veterinary colleagues to share their Internet experiences. These colleagues are Cyndi Brown, DVM, Dipl ABVP (Avian Practice), Ocean State Veterinary Specialists, East Greenwich, RI, USA; Tarah Hadley, DVM, Dipl ABVP (Avian Practice), Atlanta Hospital for Birds and Exotics, Inc, Conyers, GA, USA; Bruce Nixon, DVM, Animal Emergency Hospital of North Texas, Grapevine, TX, USA; Kimberly Mickley, DVM, Dipl ABVP (Avian Practice), Quakertown Veterinary Clinic, Quakertown, PA, USA; April Romagnano, DVM, Dipl ABVP (Avian Practice), Animal Health Clinic, Jupiter, FL, USA; and Ashley Zehnder, DVM, Dipl ABVP (Avian Practice), Cancer Biology Graduate Program, Stanford University, Newark, CA, USA. I hope that reading about their Internet experiences will make us all aware of how the technology of communication has significantly changed the way we practice as veterinarians.