Chicken Infectious Anemia Research Articles

Immunosuppressive Effects of Chicken Infectious Anaemia Virus on T Lymphocyte Populations Using Flow Cytometry and Hematological Parameters During Experimental Subclinical Infection in Chicks

Chicken infectious anaemia virus (CIAV) is an economically important pathogen affect- ing poultry industry worldwide, and renders birds susceptible to secondary infections. The present study was designed to investigate the systemic immunosuppressive effects of CIAV on T lympho- cytes bearing CD4 and CD8 receptors using flow cytometry and hematological parameters during experimental subclinical infection in chicks. Forty specific pathogen free (SPF) chicks of 6 weeks of age were randomly and equally divided into two groups. Infected group received 10 4.5 TCID 50 of CIAV while control chicks were mock inoculated. All the chicks were regularly monitored for clinical signs, hematology parameters and CD4 + and CD8 + cell populations in spleen and blood. The experimental CIAV infection was confirmed by PCR testing of the tissue samples of experimental chicks, using VP2 gene specific primers, which yielded an expected amplicon size of 651 base pairs. The analysis of the hematological parameters showed significant decline in hematocrit value (PCV), total leukocyte count (TLC) and peripheral lymphocyte count (PLC) after 15 days post infection (dpi) but with no clinical signs of CIA. Flow cytometric analysis revealed that the percentage of CD4 + CD8 - and CD4 - CD8 + T cells significantly decreased in the virus infected chicks at 15 dpi both in the spleen and blood (p<0.05). The results supported the fact that subclinical CIAV infections are also immunodepressive in nature; the virus replicates in primary lymphoid tissues and induces immunosuppression by decreasing both CD4 + and CD8 + T cells in chicks.

Tribasic copper chloride toxicosis in commercial broiler chicks.

Two broiler chicken houses containing 17,500 chicks each experienced an extreme elevation in chick mortality beginning on day 3 after placement. Clinical signs observed upon farm visit included numerous small chicks for their age; depressed, lethargic, and comatose chicks; and chicks huddling near feed pans and under heaters. Necropsied chicks were markedly pale and had atrophy of the thymus and bursa, swollen and edematous proventriculus, erosions in the koilin and in the proventricular-ventricular junction, pale kidneys, and yellowish to brownish-orange liver often with linear pale areas. The chicks had watery blood and hematocrits measured from 9.5% to 18%. Chicken infectious anemia was initially suspected based on the clinical signs and gross lesions. Histopathology revealed multifocal acute hepatic degeneration and necrosis with golden-brown pigment in the cytoplasm of hepatocytes and Kupffer cells, moderate to severe koilin degeneration and fragmentation, multifocal mild to moderate proventricular necrosis, mild to moderate necrosis and loss of enterocytes, blunting of small intestinal villi, lymphoid depletion in the thymus and bursa, erythrophagocytosis in the liver and spleen, and acute renal tubular degeneration and necrosis. Special stains revealed mild to abundant accumulation of copper pigment in the cytoplasm of hepatocytes and iron pigment in the cytoplasm of Kupffer cells. Feed analysis revealed 2140 to 2393 parts per million of copper in the starter ration, and heavy metal analysis detected markedly elevated copper levels in formalin-fixed samples of the liver. Excessive amounts of tribasic copper chloride in the starter ration caused copper toxicosis in these chicks. Similar clinical signs and lesions were reproduced when the suspect feed was used in an experimental pen trial.

Development of a DNA vaccine for chicken infectious anemia and its immunogenicity studies using high mobility group box 1 protein as a novel immunoadjuvant indicated induction of promising protective immune responses

Chicken infectious anaemia (CIA) is an economically important and emerging poultry disease reported worldwide. Current CIA vaccines have limitations like, the inability of the virus to grow to high titres in embryos/cell cultures, possession of residual pathogenicity and a risk of reversion to virulence. In the present study, a DNA vaccine, encoding chicken infectious anaemia virus (CIAV) VP1 and VP2 genes, was developed and co-administered with truncated chicken high mobility group box 1 (HMGB1ΔC) protein in young chicks for the evaluation of vaccine immune response. CIAV VP1 and VP2 genes were cloned in pTARGET while HMGB1ΔC in PET32b vector. In vitro expression of these gene constructs was evaluated by Western blotting. Further, recombinant HMGB1ΔC was evaluated for its biological activity. The CIAV DNA vaccine administration in specific pathogen free chicks resulted in moderately protective ELISA antibody titres in the range of 4322.87±359.72 to 8288.19±136.38, increased CD8+ cells, and a higher titre was observed by co-administration of novel adjuvant (HMGB1ΔC) and booster immunizations. The use of vaccine with adjuvant showed achieving antibody titres nearly 8500, titre considered as highly protective, which indicates that co-immunization of HMGB1ΔC may have a strong adjuvant activity on CIAV DNA vaccine induced immune responses. The able potential of HMGB1 protein holding strong adjuvant activity could be exploited further with trials with vaccines for other important pathogens for achieving the required protective immune responses.

전북지역 종계에서 Metapneumovirus, Reovirus, Mycoplasma 항체가 조사

Abstract We investigated the serological prevalence of avian metapneumovirus (AMPV), avian reovirus (ARV), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) in 760 broiler breeder (38 flocks), in the Jeonbuk province in 2013. This study was conducted to evaluate the immune and infection status of the broiler breeder flocks against AMPV, ARV, MG, MS by an enzyme-linked immunosorbent assay (ELISA). Serological test for AMPV were positive 37 (97.3%) flocks and 712 (93.6%) broiler breeder and geometric mean antibody titers were 16,350±10,195, ARV were high positive rate 100% (38/38) flocks and 97.8% (743/760). The seropositive flocks against MG were 71.1% (27/38) and the geometric mean antibody titers were 2,474±2,045, whereas the rates of positive flocks against MS were 50.0% (19/38) and the geometric mean antibody titers were 1,469±1,230. Key words : Broiler breeder, AMPV, ARV, MG, MS 서 론 종계를 포함한 국내 양계산업에서 Newcastle dis-ease (ND), infectious bronchitis (IB), avian influenza (AI), infectious bursal disease (IBD) 등은 오랫동안 문제시 되었던 질병일 뿐만 아니라 avian metapneumo-virus (AMPV), chicken infectious anemia virus (CIAV), avian reovirus (ARV) Mycoplasmosis (

Simultaneous typing of nine avian respiratory pathogens using a novel GeXP analyzer-based multiplex PCR assay

A new, rapid, and high-throughput GenomeLab Gene Expression Profiler (GeXP) analyzer-based multiplex PCR method was developed for simultaneous detection and differentiation of nine avian respiratory pathogens. The respiratory pathogens included in this study were avian influenza subtypes H5, H7, and H9, infectious bronchitis virus (IBV), Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS) and Haemophilus paragallinarum (HPG). Ten pairs of primers were designed using conserved and specific sequence genes of AIV subtypes and respiratory pathogens from GenBank. Single and mixed pathogen cDNA/DNA templates were used to evaluate the specificity of the GeXP-multiplex assay. The corresponding specific DNA products were amplified for each pathogen. The specific DNA product amplification peaks of nine respiratory pathogens were observed on the GeXP analyzer. Non-respiratory avian pathogens, including chicken infectious anemia virus, fowl adenovirus, avian reovirus and infectious bursal disease virus, did not produce DNA products. The detection limit for the GeXP-multiplex assay was determined to be 100 copies/μl using various pre-mixed plasmids/ssRNAs containing known target genes of the respiratory pathogens. Further, GeXP-multiplex PCR assay was 100% specific when 24 clinical samples with respiratory infections were tested in comparison with conventional PCR method. The GeXP-multiplex PCR assay provides a novel tool for simultaneous detection and differentiation of nine avian respiratory pathogens.

Experimental pathological studies of an Indian chicken anaemia virus isolate and its detection by PCR and FAT.

Chicken Infectious Anaemia Virus (CIAV) is one of the potent immunosuppressive and economically important agents affecting poultry industry worldwide. Recent reports indicate the emergence of this virus in the poultry flocks of the country. The present study aimed to investigate the pathogenic potential of a recent isolate of CIAV obtained from poultry flock of Uttaranchal State, India. Twenty first day-old age Specific Pathogen Free (SPF) chicks were inoculated intramuscularly with 10(4.5) median tissue culture infective dose (TCID50) of CIAV passaged in the Marek's disease virus transformed chicken splenic T lymphocyte (MDCC-MSB 1) cell line while 15 chicks were kept as control. The CIAV isolate produced consistent clinical signs, loss in body weight gain, anaemia, low haematocrit values, bone marrow aplasia and generalized lymphoid atrophy. Mean Packed Cell Volume (PCV) value of the infected chicks was significantly low (18.22±2.22) compared to control group (34.12±4.72) at 14 day post infection (dpi). The establishment of virus infection in chicks was confirmed both at molecular and antigenic levels by Polymerase Chain Reaction (PCR) and Indirect Immunofluorescent Test (IIFT), respectively. Characteristic apoptotic pattern was also detected in the affected organs and the virus was re-isolated successfully in MDCC-MSB1 cell cultures. The present results revealed that the virus circulating in poultry flocks of Uttaranchal state is both pathogenic and immunosuppressive in nature. Extensive epidemiological studies are suggested in the poultry flocks of the country along with adaptation of appropriate diagnostic, prevention and control strategies so as to prevent economic losses caused by this important poultry pathogen.

Seroprevalence of Five Important Viral Diseases in Commercial Chickens in Grenada, West Indies

This study was conducted to estimate the seroprevalence of New Castle disease (ND), Infectious bursal disease (IBD), Chicken infectious anemia (CIA), Avian Pneumovirus (APV) and Avian influenza (AI) in commercial chickens in Grenada, West Indies. In total, 226 and 233 sera were collected, respectively from layer (6 to 18 months age) and broiler (6 to 7 weeks of age) chickens in six regions (parishes) of Grenada and were tested using commercial ELIZA kits. The overall seroprevalence of ND, IBD, CIA, APV and AI was 47.7% (95% CI; 41.2-54.2%), 34.7% (95% CI, 28.4-40.9%), 92.9% (95% CI; 89.5-96.2%), 61.9 (95% CI, 55.6- 68.2%) and 0%, respectively for layers and 48.25 (95% CI, 41.85-54.6%), 40.35 (95% CI,34.0-46.6%), 58.3% (95% CI, 52.0-64.2%), 31.7% (95% CI.25.7-37.7%) and 0%, respectively for broilers. The presence of antibodies for more than one disease agent in the same chicken indicates that several pathogens are circulating within the same premises. This survey shows that major poultry diseases are threatening the productivity of commercial chickens in Grenada. This is the first report on disease surveillance in commercial chickens in Grenada.

Serological evidence of chicken infectious anemia in layer and broiler chickens in Grenada, West Indies

Aim: Chicken infectious anemia virus (CIAV) causes immunosuppression leading to serious losses in chickens. Though CIAV has been reported in commercial chickens from many countries of the world, no information is available on CIAV from Grenada. This paper reports the result of a serological survey of CIAV in layer and broiler chickens in Grenada. Materials and Methods: A total of 226 serum samples from layers and 233 from broiler chickens were tested for CIAV antibodies using CIAV/ELISA (IDEXX, West brook, Maine, USA). Results: The results showed seroprevalence for CIAV in layers at 92.9% (95% confidence interval, 89.55% to 96.25%) with a parish seropositivity in the range 89.28% - 100%, whereas in broilers overall seroprevalence was 58.3% (95% confidence interval, 51.97% to 64.63%) with a range of 2.85%-92.85%, according to parish. Conclusion: A high prevalence of antibodies to CIAV in commercial chickens indicates a CIAV contaminated environment in Grenada. This in turn emphasizes the need for vaccination of chickens against CIAV and further research on the impact of this disease in Grenada.

Correlation between cytokine profile,antibody titre and viral load during sub-clinical chicken anaemia virus infection

The present work was carried out to investigate the correlation between viral load and the cytokine profile and virus specific antibody levels at five day intervals up to 25 days post infection (dpi) in various tissues of chicks infected with chicken infectious anaemia virus (CIAV) at six weeks of age (sub-clinical infection) (dpi). For determining the viral load in the various tissues, recombinant plasmid vp2-pet32b was prepared and serially diluted tenfold for the generation of a standard curve using real time polymerase chain reaction (PCR). Cytokine fold changes in mRNA levels of IFN-&amp;gamma;, IL-1, IL-2, IL-12 in the spleen and IFN-&amp;gamma;, IL-12 in freshly collected whole blood were determined. The results showed that peak viral load occurs between 10&amp;ndash;20 days post infection in the lymphoid tissues viz., thymus, spleen, liver, bone marrow, bursa and also blood, being highest in blood followed by thymus. A varied response in the expression levels of individual cytokines was observed during all the intervals post infection. The IFN-&amp;gamma; increased two to five fold in blood and spleen while IL-2 decreased in the splenic tissue during the same period. Peak IFN-&amp;gamma; coincided with peak viral load in the spleen at 10 dpi while in blood it peaked earlier at five days post infection and remained high during the peak viral load at 10&amp;ndash;20 dpi. Virus specific antibodies were significantly higher at 15 dpi and were thereafter found to be strongly associated with viral load regression although higher concentrations of virus remained in the blood and thymic tissues until 25 dpi, indicating a role of other immune components in virus clearance. In conclusion, this study reports a negative correlation of viral load and the progression of the antibody response and IFN-&amp;gamma; cytokine expression in chicks infected with CIAV during their sub-clinical infectious stage. However, cytokine expression from the various individual immune cells like monocytes, heterophils, CD4&lt;sup&gt;+ &lt;/sup&gt;T, CD8&lt;sup&gt;+&lt;/sup&gt; T cells and others during the pathogenesis of this immunosuppressive poultry pathogen remains to be elucidated. &amp;nbsp;

Molecular Characterization of Chicken Infectious Anemia Virus Isolated From Commercial Poultry with Respiratory Disease Complex in India

Molecular Characterization of Chicken Infectious Anemia Virus Isolated From Commercial Poultry with Respiratory Disease Complex in India

Molecular Characterization of Chicken Infectious Anemia Virus Outbreaks during 2008-2011 in Thailand

Molecular Characterization of Chicken Infectious Anemia Virus Outbreaks during 2008-2011 in Thailand

Seromolecular study of chicken infectious anemia in chickens, ostriches, and turkeys in Iran

SUMMARY Until recently, the chicken has been considered the only natural host and the main host for chicken anemia virus (CAV). However, CAV infection has now been reported in other avian species, including Japanese quail, jackdaws, rooks, and rare avian breeds. In this study, we examined chickens, ostriches, and turkeys for seromolecular detection of CAV in Iran. For the study, 375 serum and thymus samples from chickens, 84 serum and blood samples from ostriches, and 100 serum and blood samples from turkeys were collected from various locations in Iran. Serum samples were examined using ELISA. Deoxyribonucleic acid was extracted from the thymus, and blood samples were analyzed for detection of the VP2 genome of CAV by PCR. According to these results, 69.07 and 58.4% of chickens were positive for the antibody to CAV and the VP2 genome of CAV, respectively. In addition, in ostriches 27.38 and 34.52% were positive for the CAV antibody and the CAV VP2 genome, respectively. In turkey flocks, all turkeys (100%) were negative with respect to detection of the VP2 CAV genome and CAV antibody. It was concluded that CAV is distributed in broiler chickens and ostriches throughout Iran. Furthermore, ostriches may be considered a reservoir of CAV, and turkeys appear not to be susceptible to CAV infection.

Ameliorative effects of Withania somnifera, Azadirachta indica, Tinospora cordifolia and E care Se herbal preparations on chicken infectious anaemia virus induced haematological changes in chicks and their live body weights

The present study was performed to evaluate the potential of four herbal preparations namely Withania somnifera, Tinospora cordifolia, Azadirachta indica and E Care Se Herbal against the haematological effects of chicken infectious anaemia virus (CIAV) in chicks and their live body weight gains. Briefly, six experimental groups (A to F), containing fifteen chicks each, were treated with herbal preparations separately from day old age. The chicks of Groups A to D were fed with W. somnifera (1% pure extract), T. cordifolia (1% pure extract), A. indica (0.2% pure extract) and E Care Se Herbal (0.1% in drinking water), respectively, while groups E and F were kept as virus positive and control group, respectively. Groups A to E were given infection with 40 times 50% chicken infectious dose (CID50) of CIAV A strain intra-muscularly on 14th day of age. Haematological parameters and body weight of the chicks of all the groups were recorded at weekly intervals for upto 10 weeks. The chicks of herbal treatment groups (A-D) showed significant improvement in their mean body weight gain and haematological indices viz., packed cell volume, haemoglobin level, total white blood cell, red blood cell and percentage lymphocyte counts, when compared with the virus infected group (E). In conclusion, the prophylactic/therapeutic application of these herbal preparations is suggested to combat depressed haematological parameters and stunted growth in chicks during CIAV infection. Further explorative studies would strengthen the potential role of herbs against this economically important avian pathogen causing huge economic losses to poultry farmers.

Molecular detection and epidemiology of chicken infectious anaemia virus in India

Chicken infectious anemia (CIA) is an economically important disease affecting poultry, especially young chicks, characterized by poor weight gain, anemia, immunosuppression and production losses. Recent reports indicate that the virus is emerging and re-emerging worldwide. Also, scarce reports regarding the molecular detection and epidemiology of virus from India are available. The aim of this study was to determine the prevalence of the virus in the commercial poultry farms of the country employing polymerase chain reaction (PCR). Out of the suspected 424 field samples tested from 12 different states of the country during the last five years (2007-2012), 311 (73.3%) samples were found positive for CIAV-DNA indicating the wide prevalence of the virus in India. The age wise prevalence of the virus indicated high prevalence in young chicks of up to three weeks (80.3%) of age compared to 3-7 (66.6%) and 7-12 (25%) week age groups. Being an immunosuppressive emerging pathogen circulating among the poultry flocks of the country, suitable prevention and control measures need to be adopted timely. This is a first elaborative report on the molecular epidemiology of CIAV in poultry flocks of the country. Extensive epidemiological studies are suggested to know the magnitude of the virus affecting poultry industry of the country, and design and formulate effective disease prevention and control strategies to reduce economic losses being caused by emerging virus.

Development of Enzyme-Linked Immunosorbent Assay to Detect Antibodies against Chicken Infectious Anemia Virus

Development of Enzyme-Linked Immunosorbent Assay to Detect Antibodies against Chicken Infectious Anemia Virus

English

The present study was designed to study cytokine profile and lymphocytic proliferation activity in chicken infectious anaemia virus (CIAV) infected chicks at various intervals of clinically susceptible age. Briefly, ninety specific pathogen free (SPF) chicks were divided into five experimental groups (A to E). Groups A to D were inoculated&nbsp;with 0.5 ml of 104.5TCID50&nbsp;of CIAV intramuscularly at 1, 14, 21 and 28-day-old, respectively, while&nbsp;group E served as uninfected control. Comparative cytokine gene expression levels of interleukin (IL)-1&beta;, IL-10, IL-12&beta; and granulocyte macrophage-colony stimulating factor (GM-CSF) were measured at 4 and 7 days post infection (dpi) by qRT-PCR. Also, lymphocytic proliferation activity was measured at 1, 2 and 3 week post infection (wpi) by lymphocyte transformation test (LTT).&nbsp;The down regulatory changes in cytokines and depressed&nbsp;cell mediated immune (CMI) responses were observed in chicks of all infected groups (A to D), which were significantly&nbsp;(p&lt;0.05)&nbsp;low as compared to control group. Higher intensities and more pronounced effects on cytokine downregulation and blastogenic responses of lymphocytes were seen at younger ages. Apoptosis in thymic DNA as detected by nucleosomal fragmentation was highest on 7 and 10 dpi and lowest on 14 dpi, which correlated with down regulated cytokine profile in all infected groups.&nbsp;The development of clinical signs and lesions along with PCR testing confirmed the establishment of CIAV infection in experimental chicks.&nbsp;Increased apoptosis, decreased PCV, depletion of lymphocytes, down regulated cytokine profile and reduced lymphocyte activity explain involvement of thymic and hematopoietic precursor cells leading to CMI suppression caused by CIAV. Altogether, immunopathological changes were more severe in chicks infected at younger ages as compared to later ages of the clinically susceptible period.However, further studies are suggested regarding the impact of viral load on the various cytokine profiles and revealing more about immunopathogenesis of CIAV both in young and adult birds. &nbsp; Key words:&nbsp;Chicken infectious anemia virus, cell mediated immune response, polymerase chain reaction (PCR), qRT-PCR, cytokine, apoptosis.

Dual infections with low virulent chicken infectious anaemia virus (lvCIAV) and intermediate infectious bursal disease virus (iIBDV) in young chicks increase lvCIAV in thymus and bursa while decreasing lymphocyte disorders induced by iIBDV

The use of attenuated vaccines or the occurrence of low virulent T-lymphotropic or B-lymphotropic viruses in flocks may alter the immune responses of young chicks in spite of the absence of clinical signs. Infections with a low virulent T-lymphotropic chicken infectious anaemia virus (lvCIAV) followed by infection with an intermediate B-lymphotropic infectious bursal disease virus (iIBDV) were conducted in specific pathogen free chicks. Thirty-six 1-day-old chicks were infected with the lvCIAV strain (CAV-VAC®) and a similar number of chicks were inoculated with phosphate-buffered saline. At 14 days after lvCIAV infection, one group of 18 lvCIAV-infected chicks and one group of 18 uninfected chicks were infected with an iIBDV strain. At 4, 7 and 14 days post infection with iIBDV, six chicks from each group were euthanized and lymphoid organs were collected. Detection of lvCIAV and iIBDV genomes was conducted by polymerase chain reaction and reverse transcriptase-polymerase chain reaction, respectively. Double-labelled lymphoid subsets from the thymus, spleen and bursa were studied by cytofluorometric analysis. The results reveal that previous infection with lvCIAV increases the occurrence of the lvCIAV and iIBDV genome in thymus and/or bursa without the occurrence of clinical signs in dually lvCIAV/iIBDV-infected chicks. However, the decreases of B cells in spleen and bursa and increases of T-cell subsets in bursa observed in chicks infected with iIBDV did not occur in chicks previously infected with lvCIAV. Taken together, these results suggest that previous infection of young chicks with lvCIAV decreases lymphoid disorders induced by iIBDV while subsequent iIBDV infection increases the lvCIAV genome in lymphoid organs.

Application of Real-time Polymerase Chain Reaction for Quantitative Detection of Chicken Infectious Anemia Virus

Application of Real-time Polymerase Chain Reaction for Quantitative Detection of Chicken Infectious Anemia Virus

Epidemiological investigation of outbreaks of fowl adenovirus infection in commercial chickens in Korea

In total, 39 clinical cases of fowl adenoviruses (FAdV) infection in chickens (28 broiler, 7 native, and 4 layer chickens) between 2007 and 2010 in Korea were investigated. The FAdV types 4, 8b, and 11 comprised 18, 9, and 12 clinical cases, respectively. All FAdV type 4 cases showed clinical hydropericardium (HPS) lesions as well as inclusion body hepatitis (IBH), whereas all FAdV types 8b and 11 cases exhibited IBH lesions without HPS. All 3 types were detected in broiler (9-30 d old) and layer chickens (23-112 d old), whereas most native chickens (14-65 d old) were affected only by FAdV type 4. Infectious bursal disease virus and chicken infectious anemia virus were complications in 51.3% of FAdV cases, with mortalities of 55% to <0.1%. Chicken infectious anemia virus was detected in all native chicken cases. These results indicate that preventive measures against FAdV infection and immunosuppressive diseases on poultry farms should be implemented.

Fowl Adenovirus (FAdV) in India: Evidence for Emerging Role as Primary Respiratory Pathogen in Chickens

Adenoviruses have been isolated from both clinically healthy and diseased birds worldwide. The pathogenic role of most of the FAdVs is still questionable. They can quickly take on the role of opportunistic pathogens when additional factors, particularly concurrent infections, adversely affect the health of the avian host. Immnosuppressing agents especially chicken infectious anemia and infectious bursal disease viruses are known to enhance the pathogenicity of FAdVs upon coinfection. The aim of the present study was to screen for the involvement of FAdV in poultry flocks affected with respiratory disease complex by RT-PCR. The samples were also screened by RT-PCR/PCR for other respiratory pathogens. Thirty two commercial poultry flocks with the history of respiratory disease complex from various parts of India. FAdV nucleic acid could be detected in tissue samples of 13 out of 34 farms investigated. Out of 13 FAdV positive farms, FAdV and CIAV were alone detected in 4/13 (31%) whereas, in other farms more than two respiratory pathogens were detected together. CIAV was detected in all the farms (34/34) investigated. Eosinophilic intranuclear inclusion bodies were noticed in FAdV infected laryngeal and tracheal epithelium under light microscopy. The findings of the study assert that FAdV can play the role of primary respiratory pathogen in immunocompromised birds and also in the presence of other respiratory pathogens.