Pathological Aspects of a Subclinical Marek's Disease Case in Free-Range Chickens

Abreu, Dayse L.C.; Santos, Felipe Faccini dos; José, D. S; Tortelly, Rogério; Nascimento, E. R.; Pereira, Vla

doi:10.1590/18069061-2015-0001

Cited by 12 publications

(10 citation statements)

References 6 publications

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“…On histopathological examination of the tumorous birds, the proliferation of the lymphocytes in the liver, proventriculus, kidney, bursa, nerve and other organs was observed. All the tumours birds showed gross and histopathological lesions correlated with the previous studies (Fig 1) (Abreu et al, 2016;Balachandran et al, 2009;Buscaglia et al, 2004;Fodor et al, 2001). Nontumorous birdsdid not show any histopathological changes related to Marek's disease.…”

Section: Resultssupporting

confidence: 88%

Comparative study on biological material for molecular diagnosis of Gallid herpesvirus

Balena

Reddy

Singh

2018

IJAR

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The present study was intended to investigate the sensitivity of different tissues of tumorous and non-tumorous birds to the polymerize chain reaction-baseddiagnosis of Marek's disease. Tissue samples were collected from spleen, sciatic nerve, feather follicles and tumour parts (if any)of chickens during the routine necropsy examination. The presence of Marek's disease virus was examined using primers for 132 bp repeats of BamHI-H regionand positive samples were sequenced for 132 bp repeats and Meq gene. In the birds showing tumours, various samples such as the spleen, feather pulp, sciatic nerve and tumour tissue yielded positive results in 92.31%, 88.46%, 100% and 100% cases respectively. Amongst non-tumorous birds, 11.53% spleen, 23.07% feather pulp and 11.53% sciatic nerve were found positive. This is the first comparative study between nerve and other organs samples for molecular diagnosis of Marek's disease. Data generated shows that the probability of false negative in tumorous birds and false positive in non-tumorous birds was comparatively low while employing nerve tissue than spleen and feather follicles. Thus, it may be concluded from our study that nerves are a more reliable and robust diagnostic organ in comparison to the other organs used for conventional diagnosis.

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Section: Resultssupporting

confidence: 88%

Comparative study on biological material for molecular diagnosis of Gallid herpesvirus

Balena

Reddy

Singh

2018

IJAR

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“…No entanto, é descrito que tumores linfoides podem ocorrer em qualquer local [21]. Em outro estudo, pesquisadores observaram resultados semelhantes aos do nosso grupo, como a presença de múltiplos nódulos cutâneos, esplenomegalia, nódulos no fígado, assim como alteração renal foram descritos em aves com Marek [1]. Esplenomegalia e hepatomegalia foram observados nas aves com diagnóstico de Doença de Marek, compatível com o estudo realizado com carcaças de aves em exame pós mortem, em que estiveram presentes significativamente as lesões hepáticas e esplênicas [25].…”

Section: Discussionunclassified

Risk Factors Associated with the Presence of Viral Diseases in Domestic Poultry in the Southern Region of Rio Grande do Sul, Brazil

Hirschmann

Fischer

Hübner

et al. 2019

Acta Scientiae. Vet.

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Background: The introduction of any infectious agent into an industrial or subsistence farm worries agribusiness owners in Brazil because it reduces product quality and increases treatment costs, although most diseases are untreatable, thus causing economic losses with morbidity and mortality. Therefore, an epidemiological survey of viral diseases associated with poultry was developed by performing a detailed description of the risk factors that may be related to existing diseases using domestic poultry sample data recorded in the Regional Diagnostic Laboratory (LRD) of College of Veterinary Medicine of the Federal University of Pelotas (UFPel), Rio Grande do Sul, Brazil, from 2000 to 2016.Materials, Methods & Results: Epidemiological and clinical-pathological data were collected and then compared with disease data by multivariate analysis using statistical EpiInfo version 6.04 and Microsoft Office Excel 2010 software. The frequencies and 95% confidence intervals (CI), association measures (odds ratio=OR and relative risk=RR), Chi-square test, and the results considered significant with a value of P ≤ 0.05 were described. A total of 410 samples of domestic poultry were tested, and the results showed 66 (16.1%) viral diseases. The following conditions were the most commonly found diseases in this study: Marek’s disease (42.4%), Infectious bursal disease (31.8%), Avian leukosis (16.6%), Avian pox (7.5%) and Avian infectious bronchitis (1.5%). In this article we discuss the most frequent viral diseases: Marek’s disease (DM) and Gumboro disease. It was also possible to conclude that birds with Marek's disease presented higher odds of developing nerve, tegumentary and locomotors signs (P ≤ 0.05). As well as, more likely to present tumoriform lesions in the liver, spleen, kidneys and heart P ≤ 0.05, as well as lesions in the proventriculus, muscle lesions and in the sciatic nerve P ≤ 0.05. Laying poultry, backyard poultry production and young poultry constitute risk factors for DM (P ≤ 0.05). The results showed that samples with mycotoxicoses were at higher risk of developing DM (P ≤ 0.05). Poultry from industrial system had a higher risk of developing Gumboro disease (P ≤ 0.05). Besides that, domestic poultry with Gumboro disease were more likely to develop signs of depression, nerve signals, tegumentary changes, bursitis, hepatomegaly, renal lesions and splenomegaly (P ≤ 0.05).Discussion: In this research we can observe the domestic poultry with DM presenting tumoriform lesions in several organs, this finding is common in this disease, because it is one of the most frequent viral diseases of neoplastic characteristic. The results show that young birds are a risk factor for DM. In fact, previous works already affirm young birds as being susceptible to disease in relation to adult birds. In this study, laying hens presented a risk factor for DM, however other authors also observed in cut birds or in both types of production. Industrial poultry are at higher risk for DM, this was also reported by other authors, because the disease is of high contagion and morbidity, industrial birds are under high density which facilitates the contact and dissemination of the virus among sick and susceptible birds. In this study, industrial poultry were a risk factor for Gumboro disease, however, other studies show that there is no difference between types of breeding and can also occur in backyard birds. Young poultry and laying hens are more susceptible, and the clinical signs found in the study are compatible with those described in the literature. Through this research on viral diseases, we conclude that our study may complement the already existing official data, since, in a research conducted in the same period, it did not identify the presence of viral diseases in the Southern of RS, but with our research it was possible to register this disease.

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“…Following natural infection, microscopic lesions were observed after one to two weeks, butgross lesions were observed after three to four weeks of infection (Abreu et al, 2016). The pullet showed signs of infectivity at the age of 45 and onwards, hence they may catch the infection at early age (25-30 days of age).…”

Section: Necropsy and Histopathologymentioning

confidence: 99%

Pathological investigation of Marek’s disease in a pullet farm of Bangladesh and detection of Marek’s disease virus by pcr

et al. 2018

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Marek's disease (MD) is a lymph proliferative disease of chickens, characterized by progressive emaciation, morbidity and mortality. The causative agent is a cell associated oncogenic alpha-herpes virus. This study investigated an outbreak of MD in a pullet farm (N=2200) of Ramu Upazilla, Cox's bazaar during May 2016 vaccinated against MD. The infectivity was reported on day 45 of age. Birds (N=10) submitted to diagnose disease at necropsy in the Department of Pathology, Bangladesh Agricultural University showed prominent keel bone, asymmetric progressive paralysis of one or both of the legs and wings. At necropsy, the skeletal muscle appeared thinner and there was enlargement of liver, spleen, kidney and sciatic nerve. Impression smears prepared from the liver showed huge infiltration of lymphocytes. Sections of heart, lungs, liver, kidney, nerve, skin and spleen were stained with hematoxylin and eosin showed wide spread infiltrations and accumulation of lymphocytes. Lymphocytic infiltration was seen in the skin, nerves and all visceral organs and showed combined infectivity due to visceral and classical forms. The etiology of MD was confirmed by using polymerase chain reaction (PCR) targeting fragment of Meq gene of very virulent plus or very virulent MDV1. Results of PCR showed amplification of 317bp fragment of Meq gene suggestive for infectivity due to MDV1GA (Md/5) strain. It requires isolating viruses in culture to test further for its virulence and pathotype in vivo. Sequencing and phylogenetic analysis of Meq gene may unveil the pathotype of the virus involved.

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Pathological Aspects of a Subclinical Marek's Disease Case in Free-Range Chickens

Cited by 12 publications

References 6 publications

Comparative study on biological material for molecular diagnosis of Gallid herpesvirus

Comparative study on biological material for molecular diagnosis of Gallid herpesvirus

Risk Factors Associated with the Presence of Viral Diseases in Domestic Poultry in the Southern Region of Rio Grande do Sul, Brazil

Pathological investigation of Marek’s disease in a pullet farm of Bangladesh and detection of Marek’s disease virus by pcr

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