Intestinal microbiota diversity from broilers with runting and stunting syndrome performed by metagenomics.

RESEARCH HIGHLIGHTS: RSS causes dysbiosis of the gut microbiota of the ilea of chicks.A difference was found in gut microbiota between chicks with or without RSS.Candidatus Arthromitus was predominant in chicks with RSS.Clostridium sensu stricto 1 was strictly associated with chicks with RSS.

Effects of in ovo injection of bacterial peptides and CpG-ODN on Salmonella enterica serovar Heidelberg infection in specific pathogen-free (SPF) chicks.

RESEARCH HIGHLIGHTS: Peptides + CpG-ODN reduced SH in caeca at the first week post-infection.Administered formulations did not reduce SH-faecal excretion.Levels of intestinal IgA were similar between all groups.CpG-ODN improved some parameters associated with chick intestinal health.

Feline sporotrichosis: Characterization of cutaneous and extracutaneous lesions using different diagnostic methods.

Sporotrichosis is a mycotic infection of the cutaneous and subcutaneous tissues caused by Sporothrix spp. that can also cause extracutaneous manifestations. This study aimed to characterize cutaneous and extracutaneous sporotrichosis lesions in cats. Over 1 year, 102 cats rescued by the Zoonoses Control Center of Belo Horizonte, Brazil, euthanized with clinical suspicion of feline sporotrichosis were evaluated. After euthanasia, the animals were evaluated by macroscopic, cytological, histopathological, and immunohistochemistry (IHC) examinations; fungal culture; and polymerase chain reaction (PCR). Sporothrix infection was identified by at least one diagnostic technique in all cats (n = 102) evaluated by postmortem examination, including 26/28 cases (93%) evaluated by IHC, 66/90 cases (73%) evaluated by cytology, 70/102 cases (68.6%) evaluated by histopathology, and 62/74 cases (84%) evaluated by fungal culture. Two cats had positive results only by fungal culture. Cytology and histopathology examinations were effective in diagnosing sporotrichosis, although IHC was needed to confirm the diagnosis in cats with low fungal loads. Sporothrix brasiliensis was confirmed by the sequencing of 3 samples. Skin lesions were characterized mainly by pyogranulomatous to granulomatous dermatitis (frequently with subcutaneous inflammation) with different intensities of Sporothrix spp. yeast. Extracutaneous findings associated with sporotrichosis included rhinitis or rhinosinusitis, lymphadenitis, pneumonia, meningitis, periorchitis, conjunctivitis, and glossitis. Extracutaneous infections were observed in 74/102 cases, and a possible association between the chronicity of the disease and the higher pathogenicity of this fungal species in cats requires further investigation.

Pathological findings and differential diagnoses of lymph node diseases in slaughtered cattle in Brazil: A study of 2000 samples.

Slaughterhouse inspections play a crucial role in the sanitary control of zoonoses and foodborne diseases. This study aimed to identify and analyze the frequencies of lymph node diseases in cattle slaughtered for human consumption, using the samples sent to the anatomic pathology service of the Federal Laboratory for Agricultural Defense (Laboratório Federal de Defesa Agropecuária), Minas Gerais, Brazil, from January 2015 to September 2022. In total, 2000 lymph node samples were analyzed, and additional information was individually retrieved. Lesions were most frequently identified in thoracic lymph nodes. Bacterial isolation and quantitative polymerase chain reaction (qPCR) were performed using samples suspected of tuberculosis. Tuberculosis cases accounted for 89.3% of the samples. Histopathology was more sensitive than other ancillary tests for diagnosing tuberculosis. Paraffin-embedded tissues from lymphoma cases were subjected to immunophenotyping using anti-CD3 and anti-CD79a immunohistochemistry. Frozen and/or paraffin-embedded tissues from lymphoma cases were used to identify the enzootic bovine leukosis (EBL) retrovirus through qPCR. Other diagnoses included primary (T- and B-cell lymphoma) and metastatic neoplasms (squamous cell carcinoma, pulmonary adenocarcinoma, undifferentiated carcinoma, undifferentiated adenocarcinoma, undifferentiated sarcoma, undifferentiated round cell tumor, mesothelioma, hepatic carcinoid, meningioma, and seminoma), actinogranulomas (pyogranulomatous lymphadenitis [actinobacillosis and actinomycosis]), idiopathic lymphadenitis (neutrophilic and/or histiocytic, granulomatous, and suppurative), and miscellaneous nonspecific lymphadenopathies (depletion/lymphoid atrophy, lymphangiectasia, erythrocyte drainage, parasitic eosinophilic lymphadenitis, follicular hyperplasia, and toxic granulomatous lymphadenitis). The combination of histopathology with complementary techniques is important for successful diagnosis, especially in complex cases of high epidemiological, economic, and zoosanitary importance, such as tuberculosis and EBL.

Parasitism in Rattus rattus and sympatric Achatina fulica by Angiostrongylus cantonensis in an urban park in southeast Brazil.

In this study, rodents (Rattus rattus) and mollusks (Achatina fulica) were captured in a small forest located in a large metropolitan city in Brazil, and they were examined to investigate possible parasitism by Angiostrongylus cantonensis. The parasites were recovered as helminths from the pulmonary arteries of the synanthropic rodents and as third-stage larvae (with Metastrongylidae family characteristics) from the mollusks. To confirm the species, these larvae were used to experimentally infect Rattus norvegicus for the posterior recovery of adult helminths. To identify the adult helminths, morphological, morphometric, molecular, and phylogenetic techniques were employed. Furthermore, we also characterized the histological lesions associated with parasitism in naturally infected definitive hosts. Our results demonstrated the occurrence of a natural life cycle of A. cantonensis (with the presence of adult helminths) in definitive hosts, Rattus rattus, and third-stage larvae in an intermediate host, A. fulica. In free-living rodents, lesions of granulomatous pneumonia in the lungs and meningitis in the brain were also found. These results warn of the risk of accidental transmission of A. cantonensis to human residents around the park because of the extensive interaction among the fauna of the park, domestic animals, and the surrounding human population.

Role of the IL-33/ST2 Activation Pathway in the Development of the Hepatic Fibrosis Induced by Schistosoma mansoni Granulomas in Mice.

Schistosoma mansoni eggs retained in host tissues induce innate cytokine release, contributing to the induction of Type-2 immune responses and granuloma formation, important to restrain cytotoxic antigens, but leading to fibrosis. Interleukin(IL)-33 participates in experimental models of inflammation and chemically induced fibrosis, but its role in S. mansoni-induced fibrosis is still unknown. To explore the role of the IL-33/suppressor of the tumorigenicity 2 (ST2) pathway, serum and liver cytokine levels, liver histopathology, and collagen deposition were comparatively evaluated in S. mansoni-infected wild-type (WT) and IL-33-receptor knockout (ST2-/-) BALB/c mice. Our data show similar egg counts and hydroxyproline in the livers of infected WT and ST2-/- mice; however, the extracellular matrix in ST2-/- granulomas was loose and disorganised. Pro-fibrotic cytokines, such as IL-13 and IL-17, and the tissue-repairing IL-22 were significantly lower in ST2-/- mice, especially in chronic schistosomiasis. ST2-/- mice also showed decreased α-smooth muscle actin (α-SMA) expression in granuloma cells, in addition to reduced Col III and Col VI mRNA levels and reticular fibres. Therefore, IL-33/ST2 signalling is essential for tissue repairing and myofibroblast activation during S. mansoni infection. Its disruption results in inappropriate granuloma organisation, partly due to the reduced type III and VI collagen and reticular fibre formation.

First detection of Psittacid alphaherpesvirus 5 and coinfection with beak and feather disease virus in naturally infected captive ringneck parakeets (Psittacula krameri) in Brazil.

This study describes a case report in captive rose-ringed parakeets (Psittacula krameri) that developed clinical signs and eventually died after introducing new birds without quarantine. Bronchopneumonia and airsacculitis with syncytial cells associated with intranuclear inclusion bodies were found. Herpesvirus was detected in lungs and liver by PCR, and a nearly complete genome sequence of a Psittacid alphaherpesvirus 5 was obtained from the lung of a bird. Metagenomic analysis also identified beak and feather disease virus in the same samples. The study also highlights the importance of quarantine for avoiding the introduction of new diseases in captive aviaries.

Hematological and histopathological evaluation of meat-type quails fed Madagascar cockroach meal.

Aiming at the sustainability of meat production, insects can replace traditional ingredients in the diet of poultry. Studies evaluating performance in birds have emerged to ensure this ability, but few address the health parameters of animals. This study was carried out to evaluate the effects of the inclusion of Madagascar cockroach meal in traditional diets on hematological and histopathological traits of meat-type quails. The inclusion of Madagascar cockroach meal in the diet was evaluated in four levels: 0%, 6%, 12%, and 18%. Observations for hematological and histopathological traits from 6 repetitions on each group were recorded for both sexes at 35 days of age. Hematological parameters were not influenced by Madagascar cockroach inclusion on diet and quail's sex. Red and white blood cells count were within the normal range for poultry. No significant findings were observed during the histopathological evaluation of the pancreas, duodenum, jejunum, and ileum. Liver fatty degeneration was visualized in all treatments in the same intensity. Quail's diets containing up to 18% insect meal during the growth period did not affect the studied health parameters, so the Madagascar cockroach meal could be considered as an alternative to a protein ingredient for poultry production.

Runting and Stunting Syndrome in Broiler Chickens: Histopathology and Association With a Novel Picornavirus.

Runting stunting syndrome (RSS) in commercial chickens has been reported worldwide, and although several studies have attempted to clarify the cause and describe the lesions, there are gaps in knowledge of the epidemiology, pathogenesis, and etiology. The study objective was to use commercial chicks naturally affected by RSS to describe the histologic changes of RSS in all segments of the small intestine in chicks of different ages and to identify viral gene sequences in affected chicks and their association with histologic lesions. Chicks lacking clinical signs but from the same houses and from unaffected houses were used as controls. The average weight of affected chicks was significantly lower than expected for their flocks. Macroscopically, the small intestines had paler serosa, with watery, mucoid, or foamy contents and poorly digested food. Histologic lesions were characterized by necrotic crypts, crypt dilation, and flattening of the crypt epithelium. Histomorphometry of the intestines revealed villous atrophy especially in the jejunum and ileum. Histologic changes in other organs were not observed. Random next-generation sequencing of total RNA extracted from formalin-fixed paraffin-embedded tissues detected avian nephritis virus, avian rotavirus, and picornavirus in jejunal segments from 7-day-old chicks. No viruses were detected in the jejunum of 1-day-old chicks. Detection of picornaviral reads was significantly associated (P < .05) with histologic lesions of RSS. Sequence analysis of the picornavirus revealed genetic similarity with the genus Gallivirus. Using in situ hybridization for galliviral nucleic acid sequences, the signal was associated with crypt lesion severity, although signal was detected both in chicks with and without RSS.

Molecular detection, histopathological analysis, and immunohistochemical characterization of equine infectious anemia virus in naturally infected equids.

Equine infectious anemia (EIA), a disease caused by equine infectious anemia virus (EIAV), is considered an obstacle to the development of the horse industry. There is no treatment or vaccine available for EIA, and its pathogenesis, as well as the immune response against the virus, is not fully understood. Therefore, an immunohistochemistry assay was developed for the detection of viral antigens in tissues of equids naturally infected with EIAV. Sections of organs of six equids from Apodi-RN, Brazil, that tested positive for EIA by serological tests (ELISA and AGID) were fixed in 10% formalin solution and embedded in paraffin. Immunohistochemistry was performed using a polyclonal anti-EIAV antibody. EIAV antigens were observed in red spleen pulp cells and hepatic sinusoids, as well as bronchiolar and alveolar epithelial cells of the lungs and proximal and distal tubules of the kidneys. The presence of EIAV in the spleen and liver was expected due to viral tropism by macrophages, which are abundantly present in these organs. However, EIAV was also found in lung and kidney epithelial cells, indicating that the virus infects cell types other than macrophages. In conclusion, the immunohistochemical assay standardized in this study was able to detect EIAV antigens in spleen, liver, kidney and lung cells from naturally infected EIAV equids. Immunostaining observed in the spleen confirms viral tropism by mononuclear phagocytes; however, the presence of EIAV in lung and kidney epithelial cells indicates that virus may be eliminated in urine and/or oronasal secretions, suggesting new routes for viral excretion.

Fatal necrotic tracheitis by Aviadenovirus in captive Alagoas curassows (Pauxi mitu) extinct from the wild.

Extinct from nature, captive young Alagoas curassows (Pauxi mitu) were found agonizing or dead with respiratory disease. Intranuclear inclusion bodies were found in the epithelia of the trachea, associated with marked necrotic tracheitis. An Aviadenovirus was isolated in chicken eggs and characterized genetically with 99% identity to the fowl Aviadenovirus A, as based on the hexon protein gene. This is the first report of respiratory disease caused by Aviadenovirus in any cracid species in Brazil, recommending for stricter biosecurity in the conservation premises. RESEARCH HIGHLIGHTS Fatal tracheitis in curassows extinct from nature was associated with Aviadenovirus A. Seven-month-old Alagoas curassows (Aves: Cracidae) died with haemorrhagic tracheitis. Aviadenovirus A with 99% identity to fowl adenovirus 1 was detected in dead curassows. Fatal tracheitis by Aviadenovirus was described in Pauxi mitu (Aves: Cracidae).

Genetic diversity and antimicrobial resistance profile of Enterococcus faecalis isolated from broilers with vertebral osteomyelitis in Southeast Brazil.

Vertebral osteomyelitis (VO) is a worldwide emerging disease that affects broilers. Recently, the isolation of Enterococcus faecalis in cases of the disease has been described. This study aimed at determining the genetic diversity and antimicrobial resistance profile of 12 E. faecalis strains isolated from broilers with VO. Strains were isolated from nine flocks from six farms in a high-density poultry production area in Southeast Brazil and were evaluated using multilocus sequence typing and phylogenetic analysis. Antimicrobial susceptibility tests and PCR were performed to detect antimicrobial resistance genes. E. faecalis isolates belonged to different sequence types (ST), six of which (ST49, ST100, ST116, ST202, ST249, and ST300) have been previously described. Strains ST708 and ST709 were newly identified in this study. Strain ST49 was most frequently isolated (50% of the flocks) from the analysed VO cases. No phylogenetic or phylogeographic relationship was found among the strains. The VO isolated E. faecalis strains showed highest resistance to aminoglycosides, mainly gentamicin (40%), but were highly susceptible to vancomycin (10%). Aminoglycoside resistance genes were detected in seven E. faecalis strains, and AAC6'-APH2″ genes were most frequently detected. The results showed that E. faecalis strains isolated from recently reported VO cases were highly diverse genetically. The diversity of genotypes in circulation in the analysed flocks, without apparent relationship among them, raises questions on aetiopathogenesis of the disease in broilers and evolutionary aspects of E. faecalis.

Presumed post-traumatic ocular chondrosarcoma with intrathoracic metastases in a cat.

An indoor-only, 5-year-old, spayed female domestic shorthair cat presented for an ophthalmic examination of the left eye. An intraocular tumor with secondary glaucoma and blindness was diagnosed; the globe was enucleated and sent for histopathological examination. Gross examination revealed a solid white mass filling the entire vitreous space and replacing the iris and ciliary body. The lens and retina appeared to be similarly replaced by the neoplasm. Histological examination revealed a complete loss of the internal ocular structures, with a ruptured capsule as the only remnant of the lens within an extensive malignant mesenchymal neoplastic cell proliferation. The cells were polygonal, with well-defined cytoplasmic borders and abundant weakly basophilic cytoplasm, embedded within the islands of chondroid matrix. No neoplastic invasion of the sclera was apparent. The animal died 6 months after the enucleation due to respiratory distress. Gross examination revealed numerous firm, white to tan nodular masses with smooth to mildly irregular surfaces dispersed throughout the parietal pleura, thoracic surface of the diaphragm, tracheobronchial and mediastinal lymph nodes, pericardium, and lungs. On cross-section, the neoplastic nodules were solid and variably translucent, resembling hyaline cartilage. Histologically, these nodules were similar to the neoplasm identified earlier in the left globe. Metastasis of post-traumatic ocular chondrosarcoma has not yet been described in cats. This is therefore believed to be the first report of metastases of this type of neoplasm in cats. This case adds to the limited set of data on the outcome of this type of tumor.

COELOMIC TERATOMA IN A BLUE-AND-YELLOW MACAW (ARA ARARAUNA).

A 2-mo-old, female blue-and-yellow macaw (Ara ararauna) presented with severe abdominal distension, pain, and respiratory distress. Ultrasonographic examination detected a heterogeneous mass with multiple anechoic areas, compatible with a multilocular cyst, occupying most of the coelomic cavity. Postmortem examination revealed a mass of 12.0 × 8.5 × 5.0 cm, which had an irregular surface and was connected by a pedicle to the ileum. This mass compressed and displaced the liver, proventriculus, gizzard, and intestines cranially to the left. The cut surface was lobulated, gray-white, mildly firm or soft, and was interspersed with multiple cysts filled with viscous and opaque liquid. Microscopically, it was composed of well- differentiated embryonic tissues from the endoderm, mesoderm, and ectoderm; therefore, it was diagnosed as a mature teratoma, which was theorized to have originated from Meckel's diverticulum. This study is the first, to the authors' knowledge to report a case of a teratoma in a blue-and-yellow macaw.

Evaluation of the transcriptional status of host cytokines and viral genes in the trachea of vaccinated and non-vaccinated chickens after challenge with the infectious laryngotracheitis virus.

Infectious laryngotracheitis is a highly contagious disease of chickens responsible for significant economic losses for the poultry industry worldwide. The disease is caused by Gallid herpesvirus-1 (GaHV-1) commonly known as the infectious laryngotracheitis virus. Although characterized by their potential to regain virulence, chicken embryo origin (CEO) vaccines are the most effective vaccines against laryngotracheitis as they significantly reduce the replication of challenge virus in the trachea and conjunctiva. Knowledge on the nature of protective immunity elicited by CEO vaccines is very limited. Therefore, elucidating the origin of the immune responses elicited by CEO vaccination is relevant for development of safer control strategies. In this study the transcription levels of key host immune genes (IFN-γ, IFN-ß, IL-1ß, IL-6, IL-8, IL-18) and viral genes (ICP4, ICP27, UL46, UL49), as well as viral genome loads in trachea were quantified at 6 and 12 hours post-challenge of CEO vaccinated and non-vaccinated chickens. Immediately after challenge a significant increase in IFN-γ gene expression was followed by a significant reduction in viral replication. In contrast to the rapid induction of IFN-γ, expression of the pro-inflammatory cytokines (IL-1ß, IL-6, IL-8) and type I IFN ß was either slightly reduced or remained at basal levels. These suggest that the former cytokines may not play important roles during immediate early responses induced by ILTV challenge in either vaccinated or non-vaccinated chickens. Overall, these results suggest that the rapid expression of IFN-γ may induce pathways of antiviral responses necessary for blocking early virus replication.

Vertebral osteomyelitis associated with single and mixed bacterial infection in broilers.

Vertebral osteomyelitis (VO) is a worldwide emerging disease that affects broilers. The objective of this study was to determine the frequency and aetiology of VO in broilers in a highly productive broiler region. For this, 608 broilers with locomotory problems were analysed from 18 farms. Clinical signs were recorded, necropsy was performed and samples were collected from vertebral bodies with gross changes for molecular and histopathological analysis and for bacterial isolation. From broilers with locomotory changes, 5.1% (31/608) had VO and, of these, 93.5% were 40 days old or older and 89.7% were males. The birds with VO presented varying degrees of limited mobility and this was related to the level of compression to the spinal cord. Bacterial species of the genus Enterococcus (DNA detected in 53.6%) were the aetiological agents involved in most VO cases. Enterococcus faecalis was detected most frequently (35.7%), but Enterococcus hirae was also present in some lesions (7.1%). Escherichia coli was detected in 35.7% of vertebral lesions and co-infection with E. faecalis was confirmed in 7.1% cases. Staphylococcus aureus was involved in 14.3% of the cases, being 7.1% in co-infection with Enterococcus spp. or E. hirae. Our study has indicated that, in Brazil, VO in broilers may not be caused by a single infectious agent and has a lower frequency than recently reported in other countries. This study suggests that there are geographical differences between Brazil and other countries concerning the frequency and aetiology of VO.

Diversity of Escherichia coli strains involved in vertebral osteomyelitis and arthritis in broilers in Brazil.

BACKGROUND: Locomotor disorders and infections by Escherichia coli represent major concerns to the poultry industry worldwide. Avian pathogenic E. coli (APEC) is associated with extraintestinal infections leading to respiratory or systemic disease known as colibacillosis. The most common lesions seen in cases of colibacillosis are perihepatitis, airsacculitis, pericarditis, peritonitis/salpingitis and arthritis. These diseases are responsible for significant economic losses in the poultry industry worldwide. E. coli has been recently isolated from vertebral osteomyelitis cases in Brazil and there are no data on molecular and phenotypic characteristics of E. coli strains isolated from lesions in the locomotor system of broilers. This raised the question whether specific E. coli strains could be responsible for bone lesions in broilers. The aim of this study was to assess these characteristics of E. coli strains isolated from broilers presenting vertebral osteomyelitis and arthritis in Brazil. RESULTS: Fifteen E. coli strains from bone lesions were submitted to APEC diagnosis and setting of ECOR phylogenic group, O serogroup, flagella type, virulence genes content, genetic patterns by Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST). In addition, bacterial isolates were further characterized through a lethality test, serum resistance test and antibiotic resistance profile. E. coli strains harbored different genetic pattern as assessed by PFGE, regardless of flock origin and lesion site. The strains belonged to seven sequence types (STs) previously described (ST117, ST101, ST131, ST 371 and ST3107) or newly described in this study (ST5766 and ST5856). ECOR group D (66.7 %) was the most frequently detected. The strains belonged to diverse serogroups (O88, O25, O12, and O45), some of worldwide importance. The antibiotic resistance profile confirmed strains' diversity and revealed a high proportion of multidrug-resistant strains (73 %), mainly to quinolones and beta-lactams, including third generation cephalosporin. The percentage of resistance to tetracycline was moderate (33 %) but always associated with multidrug resistance. CONCLUSIONS: Our results demonstrated that vertebral osteomyelitis and arthritis in broilers can be associated with highly diverse E. coli based on molecular and phenotypic characteristics. There was no specific virulence patterns of the E. coli strains associated with vertebral osteomyelitis or arthritis. Also, E. coli strains were frequently multidrug resistant and belonged to STs commonly shared by APEC and human ExPEC strains.

Molecular characterization of infectious laryngotracheitis virus in naturally infected egg layer chickens in a multi-age flock in Brazil.

The virus responsible for an outbreak of infectious laryngotracheitis (ILT) in a multi-age flock of egg layer chickens under quarantine in Brazil was characterized. Layer chickens from this area with circulating gallid herpesvirus 1 (GaHV 1) were evaluated using histopathology and molecular characterization techniques based on sequences of infected-cell polypeptide 4 (ICP4) and thymidine kinase (TK) genes. The infected chickens that were analyzed were PCR-positive for GaHV-1 in the trachea and negative in most trigeminal ganglia. The lack of ILT lesions in the conjunctiva and respiratory tissues, combined with detection of viral DNA in the trachea, was found to be associated with latent infection. The sequences from five farms obtained in the present study were identical, and there were no deletions within the 272- to 283-bp region of the ICP4 gene, as observed in the sequences of vaccine strains (CEO and TCO). The lack of a deletion in the ICP4 fragment analyzed in this study indicates that the chickens were infected with a field virus. The absence of the T252M mutation in a fragment of the TK gene, in addition to the low mortality rate observed, suggests that the outbreak in the state of Minas Gerais was not caused by a highly virulent strain but rather by a field virus of lower virulence. In addition, using phylogenetic reconstructions, it was found that this field strain was grouped together in a separate branch, apart from the previously characterized Brazilian strains. The introduction of vectored vaccines apparently has been effective in reducing clinical disease and lesions, and preventing new outbreaks of disease.

Fatal proventricular dilatation disease in captive native psittacines in Brazil.

An outbreak of proventricular dilatation disease (PDD), a fatal inflammatory disease of psittacines (Aves: Psittaciformes), is described in native Brazilian psittacines. Twenty captive psittacines that died of suspected PDD were necropsied and 10 were submitted to histopathology, reverse transcriptase PCR (RT-PCR), and immunohistochemistry (IHC) for avian bornavirus (ABV). Examined species were one pileated parrot (Pionopsitta pileata), three vinaceous-breasted parrots (Amazona vinacea), two blue-winged macaws (Primolius maracana), one scarlet macaw (Ara macao), one chestnut-fronted macaw (Ara severa), one scaly-headed parrot (Pionus maximiliani), and one red-browed Amazon parrot (Amazona rhodocorytha). Gross examination and histopathology revealed typical PDD lesions in all birds. The presence of ABV was confirmed in four psittacines including one red-browed Amazon parrot, one blue-winged macaw, one scarlet macaw, and one chestnut-fronted macaw. In the red-browed Amazon parrot and in one blue-winged macaw, IHC demonstrated ABV antigens in the nucleus and cytoplasm of cells in various organs. This is the first description of PDD by ABV in Brazilian psittacines and indicates the necessity for adopting a strategic control plan for reducing its impact in native birds.