Sources of persistent organic pollutants and their physiological effects on opportunistic urban gulls

Urbanization is associated with drastic shifts in biodiversity. While some species thrive in urban areas, the impact of inhabiting these human-altered environments on organism physiology remains understudied. We investigated how exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) affects the physiology of yellow-legged gulls (Larus michahellis) inhabiting a densely populated, industrialized city. We analyzed blood samples from 50 gulls (20 immatures and 30 adults) and assessed 27 physiological parameters and biomarkers related to xenobiotic protection, health, and feeding habits in these same individuals. We also tracked the movements of 25 gulls (15 immatures and 10 adults) to identify potential sources of persistent organic pollutants (POPs). Both adult and immature gulls primarily inhabited urban areas, followed by marine habitats. Immature gulls spent more time in freshwater, landfills, and agricultural areas. Bioaccumulated ΣPCB (median = 92.7 ng g-1 ww, 1.86-592) and ΣPBDE (median = 1.44 ng g-1 ww, 0.022-9.58) showed no significant differences between age and sex groups. Notably, immature males exhibited the highest correlations with POP concentrations, particularly with the activity of carboxylesterases (CEs), suggesting a higher sensitivity than adults. These findings highlight the potential of plasmatic CEs in immature yellow-legged gulls as effective tracers of POPs exposure and effects, offering insights into the anthropogenic impacts on urban biodiversity.

Blood Lipid Diagnostics in Psittacine Birds

Lipids are the main biomolecular constituents of plasma and occupy a central place in the pathophysiology of several common diseases of parrots. Dyslipidemias frequently occur in psittacine birds in relation to a variety of lipid accumulation disorders and female reproductive disorders. The five main lipid classes in the plasma are sterols, fatty acyls, glycerolipids, glycerophospholipids, and sphingolipids. Most lipids are transported in the blood within lipoproteins. Lipidologic diagnostic tests to characterize dyslipidemias and risk factors of lipid disorders include routine biochemical tests such as cholesterol and triglycerides, lipoprotein testing, and newer comprehensive techniques to assess whole lipid pathways using lipidomics.

A Spectral Computed Tomography Contrast Study: Demonstration of the Avian Cardiovascular Anatomy and Function

As part of the cardiovascular examination, all birds underwent clinical and echocardiographic examinations. Radiographs and blood samples were taken. Each bird was premedicated with midazolam and medetomidin and anesthetized with inhalation anesthesia using isoflurane. We performed computed tomographic angiography (CTA) after intravenous injection of 1 to 2 mL contrast agent per kg followed by a 1 mL saline solution flush. We were been able to identify the arteries that previous studies revealed to be most likely affected by atherosclerotic lesions: the aorta, both pulmonary arteries, and both brachiocephalic trunks. CTA was safe and is of potential diagnostic value in birds.

Evaluation of Atherosclerotic Lesions and Risk Factors of Atherosclerosis in Raptors in Northern California

Atherosclerosis is a chronic inflammatory disease that has been reported to affect the cardiovascular system of many avian species. However, atherosclerosis in raptor species has not been fully evaluated. The aim of this study was to histologically characterize central and peripheral atherosclerotic lesions in raptors that were submitted to a pathology service in Northern California from 1986 to 2013. We also evaluated risk factors, including age, gender, origin, and avian family. Atherosclerotic lesions were categorized as minimal, mild, moderate, or severe, based on the severity of the lesions and their distribution within the arterial wall. Among the central arteries, lesions were determined to be of greater severity in the aorta than in the pulmonary artery. More than 50% of the peripheral arteries were affected, including 53.1% (17/32) myocardial, 52% (13/25) coronary, 62.9% (22/35) arteries in the kidney, 52.2% (12/23) gonadal and 51.7% (15/29) splenic arteries; however, hepatic and pulmonary arteries were uncommonly affected. Atherosclerosis was diagnosed in 17 raptor species representing 4 families: Accipitridae, Cathartidae, Falconidae, and Strigidae. The overall prevalence (95% CI) of atherosclerosis in raptors was 2.3% (36/1574; range, 1.63%-3.19%) with the Falconidae having the highest prevalence at 7.4% (9/122; range 3.64%-13.93%) and with 0% detected in the Tytonidae and Pandionidae families. A multiple logistic regression model that jointly accounted for differences in risk by family, age, and gender found that the risk in Accipitridae was significantly less than that of Falconidae, that adult raptors were at greater risk of atherosclerotic lesions than juveniles were, and that females were more frequently affected than males were.

Application of Epidemiology and Principles of Herd/Flock Health for the Exotic Animal Veterinarian

Against a backdrop of climate change and epidemics, the exotic animal veterinarian is well positioned to detect emerging and exotic disease threats, prevent and control zoonotic diseases, and identify antimicrobial resistance. Within the traditional context of animal and public health, epidemiology has had a focus on veterinary preventive health and in disease investigation and control particularly in food animal and safety application. The understanding of preventive health management and veterinary epidemiology expands the repertoire of the clinical veterinarian to advise and implement and evaluate group animal health programs and biosecurity measures as well as conduct disease investigations.

Polymorphic membrane protein 20G: A promising diagnostic biomarker for specific detection of Chlamydia psittaci infection

Psittacosis is a zoonotic disease caused by Chlamydia psittaci (C. psittaci), leading to high risk for animal industry and human health. Lack of reliable commercial kits and effective vaccines is hampering control of C. psittaci infection. Polymorphic outer membrane protein Gs (PmpGs) are enriched in diverse C. psittaci, and its role are unclear during C. psittaci infection. In the present study, pmp20G gene was cloned into pET-28a vector and then the constructed plasmid was transferred into Escherichia coli Rossetta (DE3). After denaturation and renaturation, the recombinant Pmp20G-N was identified by SDS-PAGE and Western blot. Afterwards Pmp20G-N was used as the coating antigen to develop an indirect ELISA (I-ELISA) assay. Both the specificity and sensitivity of Pmp20G-N ELISA were 100%, while the MOMP-ELISA had 93.65% sensitivity and 98.94% specificity, respectively. The concordance between MOMP-ELISA and Pmp20G-N ELISA assay was 98.1%. Hence, Pmp20G-N ELISA has the potential to be a diagnostic antigen for detection C. psittaci antibody. However, further studies are needed to be done for differentiating C. psittaci from Chlamydia spp. and other C.psittaci-specific serovars using Pmp20G-N ELISA.

Lipoprotein characterization in Quaker parrots (Myiopsitta monachus) using gel-permeation high-performance liquid chromatography

BACKGROUND

Lipid accumulation disorders, such as atherosclerosis and hepatic lipidosis, are common in psittacine birds and associated with various dyslipidemias. Gel-permeation high-performance liquid chromatography (GP-HPLC) is a reference method for advanced lipoprotein profiling based on particle size separation, followed by an analysis of lipid contents.

OBJECTIVES

The objectives were to (a) characterize Quaker parrot lipoproteins using a commercial GP-HPLC method (Liposearch panel), and (b) obtain preliminary information on the reliability of the Friedewald formula for low-density lipoprotein-cholesterol (LDL-C) measurements.

METHODS

Plasma samples were collected from 12 fasted healthy Quaker parrots. Cholesterol concentrations, triglyceride concentrations, particle sizes, and particle numbers were determined by GP-HPLC for four classes and 20 sub-fractions of lipoproteins. The LDL-C concentrations obtained using the Friedewald formula and direct measurements were compared with Bland-Altman plots. Alternate formulas were determined using multiple linear regression.

RESULTS

High-density lipoprotein (HDL) was the predominant lipoprotein in Quaker parrots, and most particles were of medium-to-small sizes belonging to two sub-fractions (average size, 10.6 nm). LDL was the second most common lipoprotein and included large-to-small particles belonging to three sub-fractions (average size, 24.9 nm). Very-low-density lipoproteins (VLDL) and portomicrons were present in low concentrations. The Friedewald formula underestimated LDL-C concentrations with a significant bias of 0.44 mmol/L. An alternate formula was proposed: LDL-C = 0.75*Non-HDL-C.

CONCLUSIONS

GP-HPLC allowed unprecedented characterization of plasma lipoproteins in Quaker parrots. Characterizing psittacine lipoprotein is useful for validation and interpretation of routine clinical tests as well as for use in epidemiologic and experimental research on psittacine lipid accumulation disorders.

Captive Psittacine Birds in Ontario, Canada: a 19-Year Retrospective Study of the Causes of Morbidity and Mortality

Psittacines (e.g. parrots, macaws and cockatoos) are common companion animals that are also kept in zoos and private breeding collections. Despite this popularity, long-term, comprehensive studies of diagnostic data from captive psittacines are rare. This study was conducted to assess trends in disease prevalence and to describe causes of morbidity and mortality in psittacines submitted for post-mortem examination to the veterinary hospital and diagnostic laboratory at the University of Guelph, Ontario, Canada. Post-mortem reports of 1,850 psittacines from 1998 to 2017 were assessed and included 110 species from 45 genera. Birds were often diagnosed with infectious disease processes (n = 823; 44.5%), including viral (n = 428; 23.1%), bacterial (n = 284; 15.4%) and fungal (n = 161; 8.7%). Non-infectious disease processes (n = 1,076; 58.2%) were most commonly degenerative (n = 465; 25.1%), metabolic (n = 392; 21.2%) or haemodynamic (n = 270; 14.6%). Exploratory statistical analyses, used to guide further research, revealed significant correlations and associations among disease processes and genera, age categories and sex. This 19-year retrospective study is the first to be conducted in Canada for psittacine birds and provides a broad overview of disease prevalence that can be used as a baseline to inform other studies addressing common and uncommon diseases affecting these birds in the future.

Lipoidal corneal degeneration in aged falcons

OBJECTIVE

To present a case series of idiopathic lipoidal corneal degeneration in falcons.

ANIMALS STUDIED

Five falcons including three peregrine falcons (Falco peregrinus), one prairie falcon (Falco mexicanus), and one red-naped shaheen (Falco peregrinus babylonicus) were observed to develop slowly progressive corneal opacification that began at the temporal limbus and extended centripetally across the cornea over a period of years. Four of the birds were over 20 years old.

PROCEDURES

All animals underwent complete ophthalmic examinations. A red-naped shaheen underwent ocular imaging via spectral-domain optical coherence tomography. Two peregrine falcons were euthanized due to declining health, and their eyes were examined histologically.

RESULTS

The opacities were pale and granular, with frequent vascularization associated perilimbally. Diffuse neutral lipid was observed in stromal cells throughout the corneal stroma of both clear and opaque areas of the cornea, sparing only the acellular anterior limiting lamina. Clusters of cholesterol crystals surrounded by macrophages were present in the mid-stroma. Fibrosis was evident in a subepithelial location, which separated the epithelium from the anterior limiting lamina. Ultrastructurally, diffuse vacuolization of the keratocytes was observed. No other ophthalmic or systemic abnormalities were noted.

CONCLUSIONS

Results suggest that lipid degeneration occurs rarely in captive falcons of advanced age. The underlying cause is unclear. Though unsubstantiated, possible contributing factors include dyslipoproteinemia, corneal trauma, diet, and age-related alterations in corneal metabolism. The initiation of pathology at the temporal limbus, as well as slow progression, suggests that exposure contributes to the onset and progression of this unique keratopathy.

Evidence-Based Advances in Avian Medicine

This article presents relevant advances in avian medicine and surgery over the past 5 years. New information has been published to improve clinical diagnosis in avian diseases. This article also describes new pharmacokinetic studies. Advances in the understanding and treatment of common avian disorders are presented in this article, as well. Although important progress has been made over the past years, there is still much research that needs to be done regarding the etiology, pathophysiology, diagnosis, and treatment of avian diseases and evidence-based information is still sparse in the literature.

Infectious Diseases

The chapter describes bacerial, viral, parasitic and fungal infections commonly detected in pet birds. The chapter includes history, etiology, susceptible hosts, transmission, pathogenesis, clinical symptoms, lesion, diagnosis, zoonosis, Treatment and control strategy of Tuberculosis, Salmonellosis, Chlamydiosis, Campylobacteriosis, Lyme disease, other bacterial infection, Newcastle disease, Avian Influenza infection, West Nile Virus infection, Usutu virus infection, Avian Borna Virus infection, Beak and feather disease, other viral infection, Toxoplasmosis, Giardiasis, Cryptosporidiosis, other parasitic infection, Cryptococcosis, Aspergillosis, Other fungal infections.

Plasma Drug Concentrations of Orally Administered Rosuvastatin in Hispaniolan Amazon Parrots (Amazona ventralis)

Atherosclerotic diseases are common in pet psittacine birds, in particular Amazon parrots. While hypercholesterolemia and dyslipidemia have not definitely been associated with increased susceptibility to atherosclerosis in parrots, these are important and well-known risk factors in humans. Therefore statin drugs such as rosuvastatin constitute the mainstay of human treatment of dyslipidemia and the prevention of atherosclerosis. No pharmacologic studies have been performed in psittacine birds despite the high prevalence of atherosclerosis in captivity. Thirteen Hispaniolan Amazon parrots were used to test a single oral dose of 10 mg/kg of rosuvastatin with blood sampling performed according to a balanced incomplete block design over 36 hours. Because low plasma concentrations were produced in the first study, a subsequent pilot study using a dose of 25 mg/kg in 2 Amazon parrots was performed. Most plasma samples for the 10 mg/kg dose and all samples for the 25 mg/kg dose had rosuvastatin concentration below the limits of quantitation. For the 10 mg/kg study, the median peak plasma concentration and time to peak plasma concentration were 0.032 μg/mL and 2 hours, respectively. Our results indicate that rosuvastatin does not appear suitable in Amazon parrots as compounded and used at the dose in this study. Pharmacodynamic studies investigating lipid-lowering effects of statins rather than pharmacokinetic studies may be more practical and cost effective in future studies to screen for a statin with more ideal properties for potential use in psittacine dyslipidemia and atherosclerotic diseases.

Central vestibular disease in a blue and gold macaw (Ara ararauna) with cerebral infarction and hemorrhage

A 24-year-old female blue and gold macaw (Ara ararauna) was presented for an acute onset of left head tilt. On examination, the macaw was dehydrated and had a 120-degree left head tilt, decreased proprioception of the left pelvic limb, and intermittent vertical nystagmus. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with lymphopenia and heterophilia and a high uric acid concentration. Radiographs showed bilateral intertarsal joint osteoarthritis and a healed ulnar fracture. Magnetic resonance imaging of the brain revealed focal T2 and fluid-attenuated inversion recovery hyperintense lesions in the right cerebral hemisphere and in the midbrain. The midbrain lesion showed susceptibility artifact on the T2* sequence, suggesting hemorrhage. In the T2* sequence, iron accumulation (as seen with hemorrhage) distorts the magnetic signal, resulting in the production of a susceptibility artifact, which can then be visualized as a region of hypointensity. The bird was hospitalized but died despite intensive care. Necropsy revealed multiple cerebral vascular lesions including an acute cerebral infarct, a ruptured midbrain aneurysm, and multifocal systemic atherosclerosis. To our knowledge, this is the first report of a cerebral aneurysm in a bird. This report correlates the clinical presentation, imaging, and histopathologic findings in a macaw with central vestibular disease and demonstrates how advanced imaging techniques can identify hemorrhagic lesions through the T2* sequence.

Cluster of atherosclerosis in a captive population of black kites (Milvus migrans subsp.) in France and effect of nutrition on the plasma lipid profile

From January 2010 to March 2013, a captive colony of 83 black kites (Milvus migrans subsp.) in France experienced increased mortality related to atherosclerosis with an incidence of 4.4% per year. On histopathology, all kites had advanced atherosclerotic lesions, with several birds presenting abdominal hemorrhage and aortic rupture. In January 2012, a dietary change was instituted and consisted of introducing fish into the kites' diet. During the following 15 mo, the plasma lipid profile was monitored as well as body weight, food offered, and flight activity. Total and low-density lipoprotein cholesterol initially increased, but in December 2012 and March 2013, an overall decrease from initial values was observed. High-density lipoprotein cholesterol also increased during this period. Despite positive plasma lipid changes induced by dietary modifications, there was no decrease in mortality from atherosclerosis, which was probably associated with the severity of the atherosclerotic lesions at time of dietary management. However, owing to the long and progressive development of atherosclerotic lesions, long-term beneficial effects are probable. This report suggests that black kites are particularly susceptible to atherosclerosis and aortic dissection in captivity. To prevent degenerative diseases associated with captivity in birds of prey, species-specific lifestyle and dietary requirements and susceptibility to these diseases should be considered.

Seroprevalence and genetic characterization of Toxoplasma gondii in three species of pet birds in China

Background

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China.

Methods

A total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies were determined using the modified agglutination test (MAT). Genomic DNA was extracted from the brain tissues of seropositive pet birds and T. gondii B1 gene was amplified using a semi-nested PCR.DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP.

Results

The overall T. gondii seroprevalence was 11.21% (77/687). C. spinus had the highest T. gondii seroprevalence (11.65%), followed by A. arvensis (11.39%) and C. migratorlus (5.26%), these differences were not statistically significant (P > 0.05). Of 77 DNA samples, 8 were positive for the T. gondii B1 gene, four showed complete genotyping results. Only one genotype (the Type II variant: ToxoDB genotype #3) was identified.

Conclusions

The results of the present survey indicated the presence of T. gondii infection in pet birds in Gansu province, China. These data provide base-line information for the execution of control strategies against T. gondii infection in pet birds. To our knowledge, this is the first report documenting the occurrence of T. gondii prevalence and genotype in pet birds in China.

Chlamydia psittaci exposure in pet birds

Chlamydia psittaci is a zoonotic pathogen with a wide range of avian hosts and may be transmitted to humans and cause severe disease. To assess the risk of psittacosis posed by pet birds, the seroprevalence of Chlamydia psittaci antibodies in 360 Eurasian siskins (Carduelis spinus), 289 oriental skylarks (Alauda arvensis) and 36 black-tailed grosbeaks (Coccothraustes migratorius) in Gansu province, north-western China was detected by an indirect haemagglutination assay. Twenty-seven out of 289 (9.34 %) Alauda arvensis, 45 out of 360 (12.50 %) Carduelis spinus and 2 out of 36 (5.56 %) Coccothraustes migratorius were positive for Chlamydia psittaci infection at a cut-off dilution of 1 : 16. The prevalence of Chlamydia psittaci was higher in Carduelis spinus (12.5 %) than in Alauda arvensis (9.34 %) and Coccothraustes migratorius (5.56 %); however, the differences were not statistically significant (P>0.05). Statistical analysis indicated that Chlamydia psittaci seroprevalence in adult pet birds (12.4 %, 67/540) was significantly higher than that in juvenile pet birds (4.83 %, 7/145) (P<0.01). There was no statistical difference in Chlamydia psittaci seroprevalence between male (12.4 %) and female (8.27 %) birds. To our knowledge, this is the first report indicating the seroprevalence of Chlamydia psittaci exposure in pet birds in China. Our results indicate that close contact with pet birds poses the risk of zoonotic transmission of Chlamydia psittaci.