There is growing concern about the impact of human activities on wildlife, both at the level of the individual animal and at a global population level, and the need for surveillance of wildlife for evidence of infectious and non-infectious diseases has never been greater. There is also much interest in attempting to help wildlife by treating and rehabilitating sick and injured wild animals and by providing supplementary feeding to garden birds. This thesis reviews the literature describing the diseases found in the United Kingdom (UK) in different birds of the orders Passeriformes and Columbiformes, the orders of birds with which members of the general public and wildlife rehabilitators are most likely to have contact. The thesis then collates and analyses the postmortem findings from wild bird surveillance carried out on 2048 birds of these orders at one diagnostic laboratory in Scotland over a twenty-year period (1994- 2013). The overall aim was to make maximum use of surveillance data already gathered but not previously readily available, to inform those involved with wildlife disease surveillance, wildlife rehabilitation, and members of the public providing supplementary feeding to garden birds. During the 20 years of wild bird disease surveillance, 42 endemic conditions or pathogens were identified, raising awareness and increasing our understanding of these conditions. One re-emerging disease, salmonellosis, came to prominence and then declined during the surveillance period, and was confirmed in approximately 350 garden birds. Two new conditions were described in finches; Escherichia albertii bacteraemia in approximately 150 finches and Trichomonas gallinae infection in approximately 370 finches. The large numbers of birds with salmonellosis, E. albertii bacteraemia or trichomonosis permitted further analysis by species of bird, geographic region, and distribution by age and sex, permitting conclusions to be drawn regarding the epidemiology of these diseases. Two new conditions were diagnosed in choughs (Pyrrhocorax pyrrhocorax), a species of conservation concern in the UK; a developmental abnormality of the eye and sometimes brain of young choughs, most likely inherited, and significant helminthosis caused by spirurid gizzard worms and intestinal thorny-headed worms. These findings will influence future attempts to conserve this species in Scotland. Another new condition encountered was enteritis and/or hepatitis associated with schistosome-like eggs, diagnosed in blackbirds (Turdus merula) and a dunnock (Prunella modularis). More specific identification of the causal organism and evaluation of potential zoonotic implications are required. Two conditions were investigated for which no satisfactory aetiological agent could be identified; a nonsuppurative encephalitis affecting multiple fledgling starlings (Sturnus vulgaris) and house sparrows (Passer domesticus), and a necrotic oesophagitis of unknown cause detected in five chough nestlings. Three organisms identified in wild birds elsewhere in the world and found for the first time in the UK as part of this surveillance study were the avian gastric yeast Macrorhabdus ornithogaster (“megabacteria”) in greenfinches (Chloris chloris) and a waxwing (Bombycilla garrulus), Mycoplasma sturni in blackbirds, starlings and corvids, and Ornithonyssus sp. mites in corvids. Screening for two zoonotic pathogens exotic to UK wildlife, highly pathogenic avian influenza virus (HPAIV) and West Nile virus (WNV) was carried out on over 600 samples and over 500 samples respectively, but no positive results were obtained. Investigation of novel and re-emerging conditions and screening for exotic pathogens relied heavily on work carried out by other laboratories, underlining the importance of collaboration between multiple laboratories when carrying out disease surveillance. To aid those working in wild bird disease surveillance, diagnosis and treatment, a collection of approximately 700 images of lesions, parasites and their eggs or oocysts is included as an appendix to this thesis, as has a guide to the presumptive identification of some of the internal parasites encountered. This study has demonstrated the ever-changing nature of diseases of wild birds of the orders Passeriformes and Columbiformes, and the same is likely to be true of wild birds in other orders. Continued wild bird disease surveillance is essential, to help safeguard the health of wildlife, livestock, humans, and indeed the environment itself.

A doença de Newcastle, causada por cepas patogênicas de paramixovírus aviário 1 (APMV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Em aves da ordem Columbiformes, vários surtos têm sido relatados ao longo de 30 anos, em diferentes partes do mundo, causados por uma cepa denominada pigeon paramyxovirus tipo 1 (PPMV-1). Este trabalho descreve um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública, no município de Porto Alegre, no Sul do Brasil, ocorrido no mês de novembro de 2014. Aves moribundas e mortas, no intervalo de cinco semanas, foram submetidas ao exame de necropsia, exame histopatológico, imuno-histoquímico anti- Newcastle, de transcrição reversa seguida da reação em cadeia da polimerase (RTPCR), exame de sequenciamento e analise filogenética. Foram acometidas aves adultas, de ambos os sexos e a mortalidade foi estimada em 80%, os sinais neurológicos apresentados foram tremores da cabeça, torcicolo, dificuldade em manter-se em estação, dificuldade de locomoção, paresia, paralisia, asas caídas e vômito. As lesões encontradas no exame macroscópico eram inespecíficas e no exame histológico do sistema nervoso central eram caracterizadas por encefalite e encefalomielite não supurativas. No rim, fígado e pâncreas foi observado infiltrado inflamatório mononuclear, que por vezes era associado à necrose. No baço, além de necrose, foi observado depleção linfoide e infiltrado de macrófagos. Das 24 aves testadas para a RTPCR, seis foram positivas para a proteína da matriz (M) e através do sequenciamento destas amostras, pode-se identificar que todas as aves foram acometidas pela mesma cepa viral. Para confirmação de que a cepa encontrada tratava-se de uma cepa virulenta, foi feita a análise por sequenciamento do sítio de clivagem da proteína F, comparando a sequência de aminoácidos encontrada, 112RRQKRF117, com outras cepas já conhecidas. Observou-se que as amostras analisadas apresentaram aminoácidos na região do sítio de clivagem da proteína F, compatíveis com cepas virulentas. De acordo com a análise filogenética, o virus foi classificado como pertencente à classe II e ao genótipo VI. Ao exame imuno-histoquimico, a marcação foi observada no cérebro, no citoplasma de astrócitos e no núcleo de neurônios; no fígado, associada ao infiltrado inflamatório no interior de macrófagos; em células epiteliais do pâncreas exócrino e no citoplasma de células epiteliais do rim. / The Newcastle disease caused by avian paramyxovirus 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Over the last 30 years several outbreaks have been reported in the order Columbiformes in many parts of the world caused by a strain, known as pigeon paramyxovirus type 1 (PPMV-1). This paper describes a mortality outbreak in free-living pigeons (Columba livia) from a public square in a city in Southern Brazil, occurred in November 2014. Moribund or freshly dead pigeons, within five weeks interval, were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), Reverse transcription polymerase chain reaction (RT-PCR), sequencing analisys and phylogenetic analysis. It was affected only adult free-living pigeons of both sexes, and the mortality was estimated at 80%. Neurological signs presented by the pigeons were head tremors, stiff neck, lack of balance, incoordination, paresis, paralysis, drooped wings, and vomit. Gross findings were nonspecific. Histological findings in the central nervous system were characterized by encephalitis and encephalomyelitis nonsuppurative. In the kidney, liver and pancreas was observed mononuclear inflammatory infiltrate, which sometimes was associated with necrosis. In the spleen was observed necrosis, lymphoid depletion and macrophage infiltration. Out of 24 pigeons examined by RT-PCR, 6 pigeons had positive signal for the presence of matrix (M) protein gene and by sequencing analysis it appears that the sequences were identical to each other. The complete genome sequence and the complete coding sequence of the fusion (F) gene according to the unified NDV classification system showed that isolate had cleavage site 112RRQKRF117 which is characteristic of velogenic strains. Phylogenetic analysis showed that this strain could be classified into class II and genotype VI. Immunohistochemical analysis showed that the virus antigens were detected in astrocytes and in neurons in the brain, in liver macrophages, in exocrine pancreas epithelial cells, and in kidney epithelial cells.

No description available.

In this thesis, I present in captivity and in the field, experimental tests based on innovative feeding to a group of seven opportunistic avian species in Barbados. In chapter 1, I present an example of innovative feeding anecdotes by describing for the first time bread "hunting" and kleptoparasitisim at experimental patches by the Gray Kingbird (Tyrannus dominicensis). In chapter 2, I compare three Passeriforme (the Carib Grackle, Quiscalus lugubris; the Shiny Cowbird, Molothrus bonariensis; the Lesser-Antillean Bullfinch, Loxigilla noctis) and two Columbiforme species (the Zenaida Dove, Zenaida aurita, the Common Ground Dove, Columbina passerina ) on three measures of foraging flexibility presented in the field and in captivity: habituation to mew food patches, willingness to feed near unfamiliar objects (neophobia) and ability to obtain food from a new apparatus. In chapter 3, the two nectar-feeding species in the opportunistic "guild" of Barbados, the bullfinch and the Bananaquit (Coereba flaveola), were given a neophobia test in the field, using dissolved sugar as food. (Abstract shortened by UMI.)

A doença de Newcastle, causada por cepas patogênicas de paramixovírus aviário 1 (APMV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Em aves da ordem Columbiformes, vários surtos têm sido relatados ao longo de 30 anos, em diferentes partes do mundo, causados por uma cepa denominada pigeon paramyxovirus tipo 1 (PPMV-1). Este trabalho descreve um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública, no município de Porto Alegre, no Sul do Brasil, ocorrido no mês de novembro de 2014. Aves moribundas e mortas, no intervalo de cinco semanas, foram submetidas ao exame de necropsia, exame histopatológico, imuno-histoquímico anti- Newcastle, de transcrição reversa seguida da reação em cadeia da polimerase (RTPCR), exame de sequenciamento e analise filogenética. Foram acometidas aves adultas, de ambos os sexos e a mortalidade foi estimada em 80%, os sinais neurológicos apresentados foram tremores da cabeça, torcicolo, dificuldade em manter-se em estação, dificuldade de locomoção, paresia, paralisia, asas caídas e vômito. As lesões encontradas no exame macroscópico eram inespecíficas e no exame histológico do sistema nervoso central eram caracterizadas por encefalite e encefalomielite não supurativas. No rim, fígado e pâncreas foi observado infiltrado inflamatório mononuclear, que por vezes era associado à necrose. No baço, além de necrose, foi observado depleção linfoide e infiltrado de macrófagos. Das 24 aves testadas para a RTPCR, seis foram positivas para a proteína da matriz (M) e através do sequenciamento destas amostras, pode-se identificar que todas as aves foram acometidas pela mesma cepa viral. Para confirmação de que a cepa encontrada tratava-se de uma cepa virulenta, foi feita a análise por sequenciamento do sítio de clivagem da proteína F, comparando a sequência de aminoácidos encontrada, 112RRQKRF117, com outras cepas já conhecidas. Observou-se que as amostras analisadas apresentaram aminoácidos na região do sítio de clivagem da proteína F, compatíveis com cepas virulentas. De acordo com a análise filogenética, o virus foi classificado como pertencente à classe II e ao genótipo VI. Ao exame imuno-histoquimico, a marcação foi observada no cérebro, no citoplasma de astrócitos e no núcleo de neurônios; no fígado, associada ao infiltrado inflamatório no interior de macrófagos; em células epiteliais do pâncreas exócrino e no citoplasma de células epiteliais do rim. / The Newcastle disease caused by avian paramyxovirus 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Over the last 30 years several outbreaks have been reported in the order Columbiformes in many parts of the world caused by a strain, known as pigeon paramyxovirus type 1 (PPMV-1). This paper describes a mortality outbreak in free-living pigeons (Columba livia) from a public square in a city in Southern Brazil, occurred in November 2014. Moribund or freshly dead pigeons, within five weeks interval, were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), Reverse transcription polymerase chain reaction (RT-PCR), sequencing analisys and phylogenetic analysis. It was affected only adult free-living pigeons of both sexes, and the mortality was estimated at 80%. Neurological signs presented by the pigeons were head tremors, stiff neck, lack of balance, incoordination, paresis, paralysis, drooped wings, and vomit. Gross findings were nonspecific. Histological findings in the central nervous system were characterized by encephalitis and encephalomyelitis nonsuppurative. In the kidney, liver and pancreas was observed mononuclear inflammatory infiltrate, which sometimes was associated with necrosis. In the spleen was observed necrosis, lymphoid depletion and macrophage infiltration. Out of 24 pigeons examined by RT-PCR, 6 pigeons had positive signal for the presence of matrix (M) protein gene and by sequencing analysis it appears that the sequences were identical to each other. The complete genome sequence and the complete coding sequence of the fusion (F) gene according to the unified NDV classification system showed that isolate had cleavage site 112RRQKRF117 which is characteristic of velogenic strains. Phylogenetic analysis showed that this strain could be classified into class II and genotype VI. Immunohistochemical analysis showed that the virus antigens were detected in astrocytes and in neurons in the brain, in liver macrophages, in exocrine pancreas epithelial cells, and in kidney epithelial cells.

A doença de Newcastle, causada por cepas patogênicas de paramixovírus aviário 1 (APMV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Em aves da ordem Columbiformes, vários surtos têm sido relatados ao longo de 30 anos, em diferentes partes do mundo, causados por uma cepa denominada pigeon paramyxovirus tipo 1 (PPMV-1). Este trabalho descreve um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública, no município de Porto Alegre, no Sul do Brasil, ocorrido no mês de novembro de 2014. Aves moribundas e mortas, no intervalo de cinco semanas, foram submetidas ao exame de necropsia, exame histopatológico, imuno-histoquímico anti- Newcastle, de transcrição reversa seguida da reação em cadeia da polimerase (RTPCR), exame de sequenciamento e analise filogenética. Foram acometidas aves adultas, de ambos os sexos e a mortalidade foi estimada em 80%, os sinais neurológicos apresentados foram tremores da cabeça, torcicolo, dificuldade em manter-se em estação, dificuldade de locomoção, paresia, paralisia, asas caídas e vômito. As lesões encontradas no exame macroscópico eram inespecíficas e no exame histológico do sistema nervoso central eram caracterizadas por encefalite e encefalomielite não supurativas. No rim, fígado e pâncreas foi observado infiltrado inflamatório mononuclear, que por vezes era associado à necrose. No baço, além de necrose, foi observado depleção linfoide e infiltrado de macrófagos. Das 24 aves testadas para a RTPCR, seis foram positivas para a proteína da matriz (M) e através do sequenciamento destas amostras, pode-se identificar que todas as aves foram acometidas pela mesma cepa viral. Para confirmação de que a cepa encontrada tratava-se de uma cepa virulenta, foi feita a análise por sequenciamento do sítio de clivagem da proteína F, comparando a sequência de aminoácidos encontrada, 112RRQKRF117, com outras cepas já conhecidas. Observou-se que as amostras analisadas apresentaram aminoácidos na região do sítio de clivagem da proteína F, compatíveis com cepas virulentas. De acordo com a análise filogenética, o virus foi classificado como pertencente à classe II e ao genótipo VI. Ao exame imuno-histoquimico, a marcação foi observada no cérebro, no citoplasma de astrócitos e no núcleo de neurônios; no fígado, associada ao infiltrado inflamatório no interior de macrófagos; em células epiteliais do pâncreas exócrino e no citoplasma de células epiteliais do rim. / The Newcastle disease caused by avian paramyxovirus 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Over the last 30 years several outbreaks have been reported in the order Columbiformes in many parts of the world caused by a strain, known as pigeon paramyxovirus type 1 (PPMV-1). This paper describes a mortality outbreak in free-living pigeons (Columba livia) from a public square in a city in Southern Brazil, occurred in November 2014. Moribund or freshly dead pigeons, within five weeks interval, were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), Reverse transcription polymerase chain reaction (RT-PCR), sequencing analisys and phylogenetic analysis. It was affected only adult free-living pigeons of both sexes, and the mortality was estimated at 80%. Neurological signs presented by the pigeons were head tremors, stiff neck, lack of balance, incoordination, paresis, paralysis, drooped wings, and vomit. Gross findings were nonspecific. Histological findings in the central nervous system were characterized by encephalitis and encephalomyelitis nonsuppurative. In the kidney, liver and pancreas was observed mononuclear inflammatory infiltrate, which sometimes was associated with necrosis. In the spleen was observed necrosis, lymphoid depletion and macrophage infiltration. Out of 24 pigeons examined by RT-PCR, 6 pigeons had positive signal for the presence of matrix (M) protein gene and by sequencing analysis it appears that the sequences were identical to each other. The complete genome sequence and the complete coding sequence of the fusion (F) gene according to the unified NDV classification system showed that isolate had cleavage site 112RRQKRF117 which is characteristic of velogenic strains. Phylogenetic analysis showed that this strain could be classified into class II and genotype VI. Immunohistochemical analysis showed that the virus antigens were detected in astrocytes and in neurons in the brain, in liver macrophages, in exocrine pancreas epithelial cells, and in kidney epithelial cells.

El objetivo del presente estudio fue evaluar el grado de susceptibilidad, el efecto patológico y respuesta serológica de la paloma silvestre (especie Columba livia) frente a la inoculación experimental con una cepa de virus velogénico de la enfermedad de Newcastle. Se capturaron 28 aves adultas, 14 fueron inoculadas con una cepa velogénica viscerotrópica de la enfermedad de Newcastle, vía nasal y oral, mientras las restantes fueron criadas como grupo control. En las aves inoculadas se registró los signos clínicos y mortalidad. Se tomaron muestras de diferentes tejidos de aves que murieron así como del grupo control, para su análisis histopatológico. Se tomaron muestras de pulmón y tráquea e hisopado de cloaca para la recuperación viral, semanalmente durante seis semanas. El 64% de aves del grupo inoculado presentó signos clínicos y se obtuvo una mortalidad del 42.8%. Se presentaron estornudos a partir del cuarto día post inoculación. El erizamiento de plumas, aislamiento y letargia, se observó a partir del quinto día en aves que presentaron signos respiratorios y nerviosos. Al séptimo día se observó en el 42.8% opistótonos, tremores de cabeza y cuello que se exacerbaban al estímulo de ruidos. Al octavo día sólo en el 21 % de las aves mostraron diarrea. Los hallazgos a la necropsia consistieron en una congestión generalizada de los diferentes órganos y esplenomegalia. Las lesiones microscópicas más marcadas fueron edema, gliosis, manguito perivascular a mononucleares en cerebro y cerebelo, pérdida de cilios, infiltrado de linfocitos en tráquea, congestión interalveolar en pulmón, congestión en proventrículo, congestión e infiltración de linfocitos en intestinos y despoblamiento linfoide en bazo. El grupo inoculado mostró un incremento en sus títulos de anticuerpos a partir de la primera semana post inoculación llegando a su máximo nivel promedio geométrico de título (P.G.T) de 4.9 en la segunda semana para luego descender por completo a la quinta semana. Se logró la recuperación viral a partir de muestras de pulmón y tráquea durante las tres primeras semanas post inoculación. Se demostró que la especie Columba livia es susceptible a la inoculación experimental con una cepa velogénica del virus de la enfermedad de Newcastle. / -- This study was designed to asses the susceptibility, pathologic effect and serologic response of wild pigeons (sp. Columba livia) to Newcastle virus. A total of twenty eight adult wild pigeons were captured, fourteen were inoculated with a velogenic viscerotropic strain of Newcastle virus by oral and nasal route. The remaining pigeons were used as control group. The birds were observed to record clinical signs and mortality, also blood samples were collected for hemaglutination inhibition technique and tissue samples from lungs, tracheas and cloacal swabs were harvested for the viral recovery and histological studies. The 64 % of the inoculated group showed clinical signs and a mortality of 42.8 %. The clinical signs (sneezes, ruffled plumage, isolation and lethargy) started the fourth day post inoculation. The 43 % showed nervous signs: opisthotonos, tremors of head and neck that was exaggerated to the stimulus of noises and the 21 % showed diarrhea. In the necropsy were observed a widespread congestion and splenomegaly. The microscopic injuries were edema, gliosis, mononuclear perivascular cuffing in brain and cerebellum, loss ciliar, lymphoid infiltration in trachea, lungs congestion, proventricular congestion, and lymphocitic infiltration in intestines and lymphoid depletion in spleen. The inoculated group showed an increase in the antibody titers the first week post inoculation reaching the highest titer mean (P.G.T=4.9) in the second week after this they descended. The viral recovery was made upon lungs and tracheas tissues and from a cloacal swab in dead birds. It was showed that the specie Columba livia was susceptible to the experimental inoculation with a velogenic strain of Newcastle diasease virus.

El objetivo del presente estudio fue evaluar el grado de susceptibilidad, el efecto patológico y respuesta serológica de la paloma silvestre (especie Columba livia) frente a la inoculación experimental con una cepa de virus velogénico de la enfermedad de Newcastle. Se capturaron 28 aves adultas, 14 fueron inoculadas con una cepa velogénica viscerotrópica de la enfermedad de Newcastle, vía nasal y oral, mientras las restantes fueron criadas como grupo control. En las aves inoculadas se registró los signos clínicos y mortalidad. Se tomaron muestras de diferentes tejidos de aves que murieron así como del grupo control, para su análisis histopatológico. Se tomaron muestras de pulmón y tráquea e hisopado de cloaca para la recuperación viral, semanalmente durante seis semanas. El 64% de aves del grupo inoculado presentó signos clínicos y se obtuvo una mortalidad del 42.8%. Se presentaron estornudos a partir del cuarto día post inoculación. El erizamiento de plumas, aislamiento y letargia, se observó a partir del quinto día en aves que presentaron signos respiratorios y nerviosos. Al séptimo día se observó en el 42.8% opistótonos, tremores de cabeza y cuello que se exacerbaban al estímulo de ruidos. Al octavo día sólo en el 21 % de las aves mostraron diarrea. Los hallazgos a la necropsia consistieron en una congestión generalizada de los diferentes órganos y esplenomegalia. Las lesiones microscópicas más marcadas fueron edema, gliosis, manguito perivascular a mononucleares en cerebro y cerebelo, pérdida de cilios, infiltrado de linfocitos en tráquea, congestión interalveolar en pulmón, congestión en proventrículo, congestión e infiltración de linfocitos en intestinos y despoblamiento linfoide en bazo. El grupo inoculado mostró un incremento en sus títulos de anticuerpos a partir de la primera semana post inoculación llegando a su máximo nivel promedio geométrico de título (P.G.T) de 4.9 en la segunda semana para luego descender por completo a la quinta semana. Se logró la recuperación viral a partir de muestras de pulmón y tráquea durante las tres primeras semanas post inoculación. Se demostró que la especie Columba livia es susceptible a la inoculación experimental con una cepa velogénica del virus de la enfermedad de Newcastle. / This study was designed to asses the susceptibility, pathologic effect and serologic response of wild pigeons (sp. Columba livia) to Newcastle virus. A total of twenty eight adult wild pigeons were captured, fourteen were inoculated with a velogenic viscerotropic strain of Newcastle virus by oral and nasal route. The remaining pigeons were used as control group. The birds were observed to record clinical signs and mortality, also blood samples were collected for hemaglutination inhibition technique and tissue samples from lungs, tracheas and cloacal swabs were harvested for the viral recovery and histological studies. The 64 % of the inoculated group showed clinical signs and a mortality of 42.8 %. The clinical signs (sneezes, ruffled plumage, isolation and lethargy) started the fourth day post inoculation. The 43 % showed nervous signs: opisthotonos, tremors of head and neck that was exaggerated to the stimulus of noises and the 21 % showed diarrhea. In the necropsy were observed a widespread congestion and splenomegaly. The microscopic injuries were edema, gliosis, mononuclear perivascular cuffing in brain and cerebellum, loss ciliar, lymphoid infiltration in trachea, lungs congestion, proventricular congestion, and lymphocitic infiltration in intestines and lymphoid depletion in spleen. The inoculated group showed an increase in the antibody titers the first week post inoculation reaching the highest titer mean (P.G.T=4.9) in the second week after this they descended. The viral recovery was made upon lungs and tracheas tissues and from a cloacal swab in dead birds. It was showed that the specie Columba livia was susceptible to the experimental inoculation with a velogenic strain of Newcastle diasease virus.

A Doença de Newcastle (DN) é uma enfermidade de etiologia viral e de rápido poder de disseminação. Um grande número de espécies aviárias é susceptível ao Vírus da Doença de Newcastle (VDN). Entre estas aves, o pombo doméstico (Columba livia), tem sido incriminado como hospedeiro e disseminador da DN. Este estudo foi realizado para avaliar o comportamento de pombos frente ao VDN. Foram avaliadas a patogenia da doença e a cinética da RIH de pombos submetidos à vacinação com estirpes vivas (LaSota) e a infecção experimental com estirpe patogênica (São João do Meriti) para galinhas (Gallus gallus), para avaliar os papéis desempenhados por estas como possíveis reservatórios do VDN. A resposta sorológica foi mensurada com a técnica de HI e a eliminação do genoma viral avaliada com a técnica de RT-PCR. Foi observado que as estirpes vacinas produziram títulos elevados de anticorpos, tanto nas aves vacinadas como nas sentinelas. Na infecção experimental, demonstramos que a estirpe patogênica não produziu a doença clínica em pombos, porém promoveu a formação de anticorpos, bem como a eliminação do genoma viral. Também foi comprovada a alta infectividade do agente, tendo em vista que aves sentinelas apresentaram níveis de anticorpos elevados, nos mesmos patamares das aves infectadas. / Newcastle Disease (ND), is a highly contagious disease of viral etiology and several bird species are susceptible this disease. The domestic pigeon (Columba livia), has been regarded as a host and disseminating agent of ND. Therefore, a study was carried out in order to evaluate the responses of pigeons naturally or experimentally infected with this pathogen and the possible role of these birds as potential reservoirs of NDV. The disease pathogenesis and the kinetics of the host humoral immune response were studied in pigeons subjected to vaccination with live NDV strains (LaSota) and to experimental infection with a NDV strain (São João do Meriti) that affects domestic chickens (Gallus gallus). The serological response was measured by HI and the elimination of the viral genome was evaluated by RT-PCR. Vaccine strains induced high antibody levels, both in vaccinated and in sentinel birds. Clinical signs of the disease were not induced by the pathogenic strain in experimentally infected pigeons, although there was antibody production, as well as elimination of the viral genome. The high infectivity of the agent was also confirmed, since the sentinels birds presented high antibody levels, which were similar to the levels produced by infected birds.

A Doença de Newcastle (DN) é uma enfermidade de etiologia viral e de rápido poder de disseminação. Um grande número de espécies aviárias é susceptível ao Vírus da Doença de Newcastle (VDN). Entre estas aves, o pombo doméstico (Columba livia), tem sido incriminado como hospedeiro e disseminador da DN. Este estudo foi realizado para avaliar o comportamento de pombos frente ao VDN. Foram avaliadas a patogenia da doença e a cinética da RIH de pombos submetidos à vacinação com estirpes vivas (LaSota) e a infecção experimental com estirpe patogênica (São João do Meriti) para galinhas (Gallus gallus), para avaliar os papéis desempenhados por estas como possíveis reservatórios do VDN. A resposta sorológica foi mensurada com a técnica de HI e a eliminação do genoma viral avaliada com a técnica de RT-PCR. Foi observado que as estirpes vacinas produziram títulos elevados de anticorpos, tanto nas aves vacinadas como nas sentinelas. Na infecção experimental, demonstramos que a estirpe patogênica não produziu a doença clínica em pombos, porém promoveu a formação de anticorpos, bem como a eliminação do genoma viral. Também foi comprovada a alta infectividade do agente, tendo em vista que aves sentinelas apresentaram níveis de anticorpos elevados, nos mesmos patamares das aves infectadas. / Newcastle Disease (ND), is a highly contagious disease of viral etiology and several bird species are susceptible this disease. The domestic pigeon (Columba livia), has been regarded as a host and disseminating agent of ND. Therefore, a study was carried out in order to evaluate the responses of pigeons naturally or experimentally infected with this pathogen and the possible role of these birds as potential reservoirs of NDV. The disease pathogenesis and the kinetics of the host humoral immune response were studied in pigeons subjected to vaccination with live NDV strains (LaSota) and to experimental infection with a NDV strain (São João do Meriti) that affects domestic chickens (Gallus gallus). The serological response was measured by HI and the elimination of the viral genome was evaluated by RT-PCR. Vaccine strains induced high antibody levels, both in vaccinated and in sentinel birds. Clinical signs of the disease were not induced by the pathogenic strain in experimentally infected pigeons, although there was antibody production, as well as elimination of the viral genome. The high infectivity of the agent was also confirmed, since the sentinels birds presented high antibody levels, which were similar to the levels produced by infected birds.