PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Santos S.B., Faccini J.L.H. & Santos A.C.G. 2006. [Seasonal variation of Bovicola caprae parasitizing goats in the State of Paraíba, northeastern Brazil.] Variação estacional de Bovicola caprae parasitando caprinos no Estado da Paraíba. Pesquisa Veterinária Brasileira 26(4):249-253. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br The effects of temperature, humidity and rainfall on field population trend of the biting louse Bovicola caprae, parasitizing goats bred in the semiarid region of the State of Paraiba, northeastern Brazil were monthly evaluated from August 1999 to July 2002. In the first two years (August 1999 to July 2001) 30 goats were examined, whereas 16 goats were examined in the last year (August 2001 to July 2002). All goats were crossbred, both sexes and abated for human consumption. The lice were collected in an area 4cm of diameter at three body sites: maxillary, back line and haunch. Spearman correlation analysis was conducted (p< 0.05) between monthly average intensity of infestation of all stages (egg, larva, nymph, male and female) of the life cycle pooled and monthly total counts of each stage and mean temperature, mean relative humidity and rainfall. B. caprae was found throughout the year with prevalence of 75-100%. Increase of the louse population during the drier months was probably a consequence of poor nutrition due to reduced pasture and inadequate husbandry practices instead the influence of abiotic factors.

• Bovicola caprae Trichodectidae Mallophaga seasonal variation goats northeastern Brazil

Abstract in Portuguese:

ABSTRACT.- Santos S.B., Faccini J.L.H. & Santos A.C.G. 2006. [Seasonal variation of Bovicola caprae parasitizing goats in the State of Paraíba, northeastern Brazil.] Variação estacional de Bovicola caprae parasitando caprinos no Estado da Paraíba. Pesquisa Veterinária Brasileira 26(4):249-253. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br The effects of temperature, humidity and rainfall on field population trend of the biting louse Bovicola caprae, parasitizing goats bred in the semiarid region of the State of Paraiba, northeastern Brazil were monthly evaluated from August 1999 to July 2002. In the first two years (August 1999 to July 2001) 30 goats were examined, whereas 16 goats were examined in the last year (August 2001 to July 2002). All goats were crossbred, both sexes and abated for human consumption. The lice were collected in an area 4cm of diameter at three body sites: maxillary, back line and haunch. Spearman correlation analysis was conducted (p< 0.05) between monthly average intensity of infestation of all stages (egg, larva, nymph, male and female) of the life cycle pooled and monthly total counts of each stage and mean temperature, mean relative humidity and rainfall. B. caprae was found throughout the year with prevalence of 75-100%. Increase of the louse population during the drier months was probably a consequence of poor nutrition due to reduced pasture and inadequate husbandry practices instead the influence of abiotic factors.

Abstract in English:

ABSTRACT.- Barbosa J.D., Oliveira C.M.C., Tokarnia C.H. & Peixoto P.V. 2006. [Hepatogenous photosensitization in horses caused by Brachiaria humidicola (Gramineae) in the State of Pará.] Fotossensibilização hepatógena em eqüinos pela ingestão de Brachiaria humidicola (Gramineae) no Estado do Pará. Pesquisa Veterinária Brasileira 26(3):147-153. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743-080, Brazil. E-mail: diomedes@ufpa.br Data on the clinical-pathological aspects and on the epidemioloy of a disease in horses, characterized by phototsensitization, which occurs in northeastern of Pará, Brazil, are presented. Of a total of 40 horses examined clinically, post-mortem examination was performed on seven. Due to the characteristic lesions found on the non-pigmented skin, the macroscopic and histological alterations in the liver, and knowing that Brachiaria grasses contain saponins with toxic properties, which cause liver lesions and photosensitization in cattle and sheep, it is concluded that this disease in horses is caused by grassing exclusively Brachiaria humidicola.

• Poisonous plants Brachiaria humidicola plant poisoning photosensitization saponins horses

Abstract in Portuguese:

ABSTRACT.- Barbosa J.D., Oliveira C.M.C., Tokarnia C.H. & Peixoto P.V. 2006. [Hepatogenous photosensitization in horses caused by Brachiaria humidicola (Gramineae) in the State of Pará.] Fotossensibilização hepatógena em eqüinos pela ingestão de Brachiaria humidicola (Gramineae) no Estado do Pará. Pesquisa Veterinária Brasileira 26(3):147-153. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743-080, Brazil. E-mail: diomedes@ufpa.br Data on the clinical-pathological aspects and on the epidemioloy of a disease in horses, characterized by phototsensitization, which occurs in northeastern of Pará, Brazil, are presented. Of a total of 40 horses examined clinically, post-mortem examination was performed on seven. Due to the characteristic lesions found on the non-pigmented skin, the macroscopic and histological alterations in the liver, and knowing that Brachiaria grasses contain saponins with toxic properties, which cause liver lesions and photosensitization in cattle and sheep, it is concluded that this disease in horses is caused by grassing exclusively Brachiaria humidicola.

Abstract in English:

ABSTRACT.- Bianchin I., Koller W.W. & Detmann E. 2006. [The seasonality of Haematobia irritans in central Brazil.] Sazonalidade de Haematobia irritans no Brasil Central. Pesquisa Veterinária Brasileira 26(2):79-86. Área de Sanidade Animal, Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: bianchin@cnpgc.embrapa.br Horn fly (Haematobia irritans) is one of the most important Brazilian cattle ectoparasites. Epidemiological studies are needed due the increasing difficulty of their chemical control. In order to obtain a better knowledge of their seasonal population dynamics, 14 days interval fly counts were made on 7-30 month old beef cattle, from winter 1996 to summer 2002. Horn fly population levels increase (P<0.05) was observed during the seasons of each infestation period (spring until autumn), mainly in spring and summer, and sometimes in autumn, followed by a significant reduction (P<0.05) in winter, when the relative humidity decreases to less than 60%. A straight (P<0.05) and immediate correlation between the relative humidity and the fly count was found, whilst the most evident effects of temperature and rain fall (P<0.05) were associated with counts done 42-56 days after attainment of the climatic data. The highest parasitism load (average number of flies per animal) observed for the genetic groups used were: Aberdeen Angus x Nellore = 173.5 (134-254); ½ Brown Swiss x Nellore = 183.5 (32-540); ¾ Aberdeen Angus x Nellore = 133.0 (18-374), and Valdostana x Nellore = 219.0 (58-620). Torrential rain falls during the initial half of the infestation period (spring until midsummer) are common in this region and were considered the main reason for the low to moderate population levels verified at that time, in comparison with those which occurred during the last half of the infestation period.

• Horn fly epidemiology population dynamics ectoparasites cattle.

Abstract in Portuguese:

ABSTRACT.- Bianchin I., Koller W.W. & Detmann E. 2006. [The seasonality of Haematobia irritans in central Brazil.] Sazonalidade de Haematobia irritans no Brasil Central. Pesquisa Veterinária Brasileira 26(2):79-86. Área de Sanidade Animal, Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: bianchin@cnpgc.embrapa.br Horn fly (Haematobia irritans) is one of the most important Brazilian cattle ectoparasites. Epidemiological studies are needed due the increasing difficulty of their chemical control. In order to obtain a better knowledge of their seasonal population dynamics, 14 days interval fly counts were made on 7-30 month old beef cattle, from winter 1996 to summer 2002. Horn fly population levels increase (P<0.05) was observed during the seasons of each infestation period (spring until autumn), mainly in spring and summer, and sometimes in autumn, followed by a significant reduction (P<0.05) in winter, when the relative humidity decreases to less than 60%. A straight (P<0.05) and immediate correlation between the relative humidity and the fly count was found, whilst the most evident effects of temperature and rain fall (P<0.05) were associated with counts done 42-56 days after attainment of the climatic data. The highest parasitism load (average number of flies per animal) observed for the genetic groups used were: Aberdeen Angus x Nellore = 173.5 (134-254); ½ Brown Swiss x Nellore = 183.5 (32-540); ¾ Aberdeen Angus x Nellore = 133.0 (18-374), and Valdostana x Nellore = 219.0 (58-620). Torrential rain falls during the initial half of the infestation period (spring until midsummer) are common in this region and were considered the main reason for the low to moderate population levels verified at that time, in comparison with those which occurred during the last half of the infestation period.

Abstract in English:

Ristow P., Silva M.G., Fonseca L.S. & Lilenbaum W. 2006. [Evaluation of Mycobac-terium avium subsp. paratuberculosis faecal culture protocols and media.] Pesquisa Veteri-nária Brasileira 26(1):1-4. Mycobacteria Laboratory, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ 21941-590, Brazil. E-mail: paularistow@bigfoot.com Paratuberculosis is an important enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). The disease is officially considered exotic in Brazil, but recent serological surveys and the isolation of the agent suggest it may occur in our herds. The aim of this study was to evaluate three different formulations of Herrold’s egg yolk agar with mycobactin J (HEYM) and four faecal culture protocols considering their ability for Map growth as well as cost and ease of application. Three formulations of HEYM were inoculated with two suspensions of Map. Spiked faeces and naturally contaminated faecal samples were treated by the four faecal culture protocols. Centrifugation protocol and HEYM recommended by OIE showed the best results on the recovery of Map.

• Paratuberculosis bovine diagnosis mycobacterium.

Abstract in Portuguese:

Ristow P., Silva M.G., Fonseca L.S. & Lilenbaum W. 2006. [Evaluation of Mycobac-terium avium subsp. paratuberculosis faecal culture protocols and media.] Pesquisa Veteri-nária Brasileira 26(1):1-4. Mycobacteria Laboratory, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ 21941-590, Brazil. E-mail: paularistow@bigfoot.com Paratuberculosis is an important enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). The disease is officially considered exotic in Brazil, but recent serological surveys and the isolation of the agent suggest it may occur in our herds. The aim of this study was to evaluate three different formulations of Herrold’s egg yolk agar with mycobactin J (HEYM) and four faecal culture protocols considering their ability for Map growth as well as cost and ease of application. Three formulations of HEYM were inoculated with two suspensions of Map. Spiked faeces and naturally contaminated faecal samples were treated by the four faecal culture protocols. Centrifugation protocol and HEYM recommended by OIE showed the best results on the recovery of Map.

Abstract in English:

Riet-Correa G., Duarte M.D., Barbosa J.D., Oliveira C.M.C., Cerqueira V.D., Brito M.F. & Riet-Correa F. 2006. [Meningoencephalitis and polioencephalomalacia caused by Bovine herpesvirus-5 in the state of Pará, northern Brazil.] Meningoencefalite e polioencefalomalacia causadas por Herpesvírus bovino-5 no Estado do Pará. Pesquisa Veterinária Brasileira 26(1):44-46. Central de Diagnóstico Veterinário, Universidade Federal do Pará, Maximino Porpino 1000, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Four outbreaks of meningoencephalitis in 1 to 2 years old cattle caused by Bovine herpesvirus-5 are reported in four municipalities in the state of Pará, northern Brazil. In three outbreaks only one animal was affected, in another 3 cattle were affected. Main clinical signs were incoordination, dullness, blindness, recumbence, and opisthotonus. Death occurred after a clinical manifestation period of 3-4 days. Softening and yellowish areas were observed grossly in the cerebral cortex. The histology revealed poliencephalomalacia in the cerebral cortex, thalamus and basal nuclei, and non suppurative encephalitis and meningitis, and eosinophilic intranuclear inclusion bodies in astrocytes. The diagnosis was based on the typical microscopic lesions.

• Meningoencephalitis polioencephalomalacia bovine herpesvirus-5 cattle.

Abstract in Portuguese:

Riet-Correa G., Duarte M.D., Barbosa J.D., Oliveira C.M.C., Cerqueira V.D., Brito M.F. & Riet-Correa F. 2006. [Meningoencephalitis and polioencephalomalacia caused by Bovine herpesvirus-5 in the state of Pará, northern Brazil.] Meningoencefalite e polioencefalomalacia causadas por Herpesvírus bovino-5 no Estado do Pará. Pesquisa Veterinária Brasileira 26(1):44-46. Central de Diagnóstico Veterinário, Universidade Federal do Pará, Maximino Porpino 1000, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Four outbreaks of meningoencephalitis in 1 to 2 years old cattle caused by Bovine herpesvirus-5 are reported in four municipalities in the state of Pará, northern Brazil. In three outbreaks only one animal was affected, in another 3 cattle were affected. Main clinical signs were incoordination, dullness, blindness, recumbence, and opisthotonus. Death occurred after a clinical manifestation period of 3-4 days. Softening and yellowish areas were observed grossly in the cerebral cortex. The histology revealed poliencephalomalacia in the cerebral cortex, thalamus and basal nuclei, and non suppurative encephalitis and meningitis, and eosinophilic intranuclear inclusion bodies in astrocytes. The diagnosis was based on the typical microscopic lesions.

Abstract in English:

Santurio J.M., Leal A.T., Leal A.B.M., Alves S.H., Lübeck I., Griebeler J. & Copetti M.V. 2006. [Indirect ELISA for the serodiagnostic of pythiosis.] Teste de ELISA indireto para o diagnóstico sorológico de pitiose. Pesquisa Veterinária Brasileira 26(1):47-50. Departamento de Microbiologia, Universidade Federal de Santa Maria, prédio 20, sala 4139, Lapemi, Santa Maria, RS 97105-900, Brazil. E-mail: santurio@smail.ufsm.br Pythiosis is a granulomatous disease caused by the oomycete Pythium insidiosum that affects humans and animals, especially horses. Deaths are very often the consequence of incorrect or late diagnosis when animals no longer respond to treatment. This study aimed standardization of the ELISA assay for the serodiagnostic of pythiosis in horses and rabbits, in order to minimize errors and delays in the diagnosis of the disease. Sera of 72 healthy and 44 of by pythiosis affected horses were used for development and evaluation of the test. The ELISA for equine diagnostic showed 97.72% sensitivity, 90.27% specificity, 86% positive predictive value, 98.4% negative predictive value, and 93.1% efficiency. The rabbit test was standardized with 48 sera of healthy rabbits and 24 sera of rabbits immunized with P. insidiosum antigens. The results were 91.66 % sensitivity, 95.83% specificity, 91.66% positive predictive value, 95.83% negative predictive value, and 94.44% efficiency. It can be concluded that ELISA is a reliable test for diagnostic and serological monitoring of pythiosis.

• Pythium insidiosum pythiosis ELISA horses rabbits.

Abstract in Portuguese:

Santurio J.M., Leal A.T., Leal A.B.M., Alves S.H., Lübeck I., Griebeler J. & Copetti M.V. 2006. [Indirect ELISA for the serodiagnostic of pythiosis.] Teste de ELISA indireto para o diagnóstico sorológico de pitiose. Pesquisa Veterinária Brasileira 26(1):47-50. Departamento de Microbiologia, Universidade Federal de Santa Maria, prédio 20, sala 4139, Lapemi, Santa Maria, RS 97105-900, Brazil. E-mail: santurio@smail.ufsm.br Pythiosis is a granulomatous disease caused by the oomycete Pythium insidiosum that affects humans and animals, especially horses. Deaths are very often the consequence of incorrect or late diagnosis when animals no longer respond to treatment. This study aimed standardization of the ELISA assay for the serodiagnostic of pythiosis in horses and rabbits, in order to minimize errors and delays in the diagnosis of the disease. Sera of 72 healthy and 44 of by pythiosis affected horses were used for development and evaluation of the test. The ELISA for equine diagnostic showed 97.72% sensitivity, 90.27% specificity, 86% positive predictive value, 98.4% negative predictive value, and 93.1% efficiency. The rabbit test was standardized with 48 sera of healthy rabbits and 24 sera of rabbits immunized with P. insidiosum antigens. The results were 91.66 % sensitivity, 95.83% specificity, 91.66% positive predictive value, 95.83% negative predictive value, and 94.44% efficiency. It can be concluded that ELISA is a reliable test for diagnostic and serological monitoring of pythiosis.

Abstract in English:

Medeiros J.M., Tabosa I.M., Simões S.V.D., Nóbrega Jr J. E., Vasconcelos J.S. & Riet-Correa F. 2005. [Perinatal mortality in kids in the semiarid region of Paraíba, Brazil.] Mortalidade perinatal em cabritos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 25(4):201-206. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-970 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br The causes of perinatal kid mortality were studied from May 2002 to August 2004 in the semiarid region of Paraíba. In 118 necropsied kids the frequency of different causes of death were neonatal infections (50%), distocia (12.71%), hypothermia/starvation (11.86%), malformations (7.62%), floppy kid (6.77%) and abortions (1.69%). Regarding the time of death, 1.69% of the kids died before parturition, 16.94% during the parturition and 81.34 % after birth. The high occurrence of neonatal infections, dystocias, and hypothermia/starvation is probably to due to factors related with error in the sanitary, reproductive and nutritional management. Arthrogryposis of the forelimbs was the main malformation observed. This defect is endemic in goat flocks in the semi-arid of Brazil. Most deaths occurred after birth (25.42%) and from the 4th to the 28th day of life (38.98%) suggesting that care with the kids during their first 28 days of life is important for the improvement of the survival rate.

• Perinatal mortality kids semiarid region Brazil.

Abstract in Portuguese:

Medeiros J.M., Tabosa I.M., Simões S.V.D., Nóbrega Jr J. E., Vasconcelos J.S. & Riet-Correa F. 2005. [Perinatal mortality in kids in the semiarid region of Paraíba, Brazil.] Mortalidade perinatal em cabritos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 25(4):201-206. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-970 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br The causes of perinatal kid mortality were studied from May 2002 to August 2004 in the semiarid region of Paraíba. In 118 necropsied kids the frequency of different causes of death were neonatal infections (50%), distocia (12.71%), hypothermia/starvation (11.86%), malformations (7.62%), floppy kid (6.77%) and abortions (1.69%). Regarding the time of death, 1.69% of the kids died before parturition, 16.94% during the parturition and 81.34 % after birth. The high occurrence of neonatal infections, dystocias, and hypothermia/starvation is probably to due to factors related with error in the sanitary, reproductive and nutritional management. Arthrogryposis of the forelimbs was the main malformation observed. This defect is endemic in goat flocks in the semi-arid of Brazil. Most deaths occurred after birth (25.42%) and from the 4th to the 28th day of life (38.98%) suggesting that care with the kids during their first 28 days of life is important for the improvement of the survival rate.

Abstract in English:

Lima V.M.F., Biazzono L., Silva A.C., Correa A.P.F.L. & Luvizotto M.C.R. 2005. Serological diagnosis of visceral leishmaniasis by an enzyme immunoassay using protein A in naturally infected dogs. Pesquisa Veterinária Brasileira 25(4):215-218. Departamento de Clínica, Cirurgia e Reprodução Animal, Faculdade de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana 793, Araçatuba, SP 16050-680, Brazil. E-mail: vmflima@fmva.unesp.br A rapid indirect enzyme-linked immunosorbent assay (ELISA) was developed for measuring antibodies against Leishmania chagasi using total antigen from lysed promastigotes. Fifty symptomatic mixed breed dogs from a region of high incidence of visceral leishmaniasis in Brazil were examined. The results showed that in the positive animals, diagnosed by cytological examination, the ELISA using protein A assay system (mean optical density ± SD / 2.078 ± 0.631) detected more antibodies than the anti-IgG assay (mean optical density ± SD / 1.008 ± 0.437), while in the negative animals, the results by both systems were similar. These results suggest that the ELISA assay using protein A peroxidase conjugated could be useful to detect early infected animals in endemic areas, and thus help to control the spread of the infection.

• Leishmania chagasi visceral leishmaniasis protein A dogs.

Abstract in Portuguese:

Lima V.M.F., Biazzono L., Silva A.C., Correa A.P.F.L. & Luvizotto M.C.R. 2005. Serological diagnosis of visceral leishmaniasis by an enzyme immunoassay using protein A in naturally infected dogs. Pesquisa Veterinária Brasileira 25(4):215-218. Departamento de Clínica, Cirurgia e Reprodução Animal, Faculdade de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana 793, Araçatuba, SP 16050-680, Brazil. E-mail: vmflima@fmva.unesp.br A rapid indirect enzyme-linked immunosorbent assay (ELISA) was developed for measuring antibodies against Leishmania chagasi using total antigen from lysed promastigotes. Fifty symptomatic mixed breed dogs from a region of high incidence of visceral leishmaniasis in Brazil were examined. The results showed that in the positive animals, diagnosed by cytological examination, the ELISA using protein A assay system (mean optical density ± SD / 2.078 ± 0.631) detected more antibodies than the anti-IgG assay (mean optical density ± SD / 1.008 ± 0.437), while in the negative animals, the results by both systems were similar. These results suggest that the ELISA assay using protein A peroxidase conjugated could be useful to detect early infected animals in endemic areas, and thus help to control the spread of the infection.

Abstract in English:

Rodrigues A., Fighera R.A., Souza T.M., Schild A.L., Soares M.P., Milano J. & Barros C.S.L. 2005. [Outbreaks of trypanosomiasis in horses by Trypanosoma evansi in the state of Rio Grande do Sul, Brazil: epidemiological, clinical, hematological, and pathological aspects.] Surtos de tripanossomíase por Trypanosoma evansi em eqüinos no Rio Grande do Sul: aspectos epidemiológicos, clínicos, hematológicos e patológicos. Pesquisa Veterinária Brasileira 25(4):239-249. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Cases of trypanosomiasis by Trypanosoma evansi were diagnosed in horses in the state of Rio Grande do Sul, Brazil, between 2003 and 2004. In one stud farm (Farm A) with 125 horses, 52 died. Additionally, around 80 mares were sent to Farm A to be bred. Of those, 66 became ill and 56 died after being returned to their farms of origin. Twenty one horses clinically affected by the disease were observed. Clinical signs included loss of weight (despite voracious appetite), lethargy, incoordination and instability of hindlimbs, atrophy of the large muscles of the hindlimbs, muscle weakness and paleness of mucosae. Specimens of T. evansi were detected in the blood drawn from four affected horses. Normocytic normochromic anemia with PCVs ranging from 15 to 31%, leucocytosis due to lymphocytosis associated to large atypical lymphocytes was observed in several affected horses. High levels of antibodies against T. evansi were detected in the serum of six horses from Farm A. Eight horses presented encephalic neurological signs such as circling, ataxia, blindness, excitation, falls, listlessness, proprioception deficits and head tilt. One horse assumed a “dog-seating position”. Necropsy findings included muscle atrophy, enlargement and lymphoid hyperplasia of the spleen and lymphnodes, edema and softening of the white and grey matter of the brain. Histologically, an overwhelming necrotizing panencephalitis was observed in the seven horses with encephalic signs. This panencephalitis was characterized by marked edema, demyelination and necrosis and perivascular infiltrates of 6-10 layers of lymphocytes and plasm cells affecting both the white and gray matter. Several plasm cells in the inflammatory infiltrate contained numerous eosinophilic globules in their cytoplasm (Mott cells). Similar histological lesions were observed in the spinal cord of the horse with the “dog-seating position”. The brains of five horses with the encephalic signs were submitted to immunohistochemistry stain by the streptavidin-biotin technique. In all of those five brains moderate to abundant specimens of T. evansi in the perivascular spaces and neuropile were marked by the specific antibody. Epidemiological, clinical, hematological, and pathological aspects of equine trypanosomiasis caused by T. evansi are discussed.

• Trypanosomiasis Trypanosoma evansi infectious diseases encephalitis hematology pathology diseases of horses.

Abstract in Portuguese:

Rodrigues A., Fighera R.A., Souza T.M., Schild A.L., Soares M.P., Milano J. & Barros C.S.L. 2005. [Outbreaks of trypanosomiasis in horses by Trypanosoma evansi in the state of Rio Grande do Sul, Brazil: epidemiological, clinical, hematological, and pathological aspects.] Surtos de tripanossomíase por Trypanosoma evansi em eqüinos no Rio Grande do Sul: aspectos epidemiológicos, clínicos, hematológicos e patológicos. Pesquisa Veterinária Brasileira 25(4):239-249. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Cases of trypanosomiasis by Trypanosoma evansi were diagnosed in horses in the state of Rio Grande do Sul, Brazil, between 2003 and 2004. In one stud farm (Farm A) with 125 horses, 52 died. Additionally, around 80 mares were sent to Farm A to be bred. Of those, 66 became ill and 56 died after being returned to their farms of origin. Twenty one horses clinically affected by the disease were observed. Clinical signs included loss of weight (despite voracious appetite), lethargy, incoordination and instability of hindlimbs, atrophy of the large muscles of the hindlimbs, muscle weakness and paleness of mucosae. Specimens of T. evansi were detected in the blood drawn from four affected horses. Normocytic normochromic anemia with PCVs ranging from 15 to 31%, leucocytosis due to lymphocytosis associated to large atypical lymphocytes was observed in several affected horses. High levels of antibodies against T. evansi were detected in the serum of six horses from Farm A. Eight horses presented encephalic neurological signs such as circling, ataxia, blindness, excitation, falls, listlessness, proprioception deficits and head tilt. One horse assumed a “dog-seating position”. Necropsy findings included muscle atrophy, enlargement and lymphoid hyperplasia of the spleen and lymphnodes, edema and softening of the white and grey matter of the brain. Histologically, an overwhelming necrotizing panencephalitis was observed in the seven horses with encephalic signs. This panencephalitis was characterized by marked edema, demyelination and necrosis and perivascular infiltrates of 6-10 layers of lymphocytes and plasm cells affecting both the white and gray matter. Several plasm cells in the inflammatory infiltrate contained numerous eosinophilic globules in their cytoplasm (Mott cells). Similar histological lesions were observed in the spinal cord of the horse with the “dog-seating position”. The brains of five horses with the encephalic signs were submitted to immunohistochemistry stain by the streptavidin-biotin technique. In all of those five brains moderate to abundant specimens of T. evansi in the perivascular spaces and neuropile were marked by the specific antibody. Epidemiological, clinical, hematological, and pathological aspects of equine trypanosomiasis caused by T. evansi are discussed.

Abstract in English:

Tancredi M.G.F., Faccini J.L.H., Tancredi I.P., Martins I.V.F. & Scott F.B. 2005. [The host-relationship between Psoroptes equi and horses.] Relação parasito-hospedeiro entre Psoroptes equi e eqüinos. Pesquisa Veterinária Brasileira 25(4):207-209. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br Horses, abandoned by their owners (stray horses) along the main roads in the state of Rio de Janeiro, southeastern Brazil, and brought by the Federal Police to a quarantine station at the Universidade Federal Rural do Rio de Janeiro, were included in the study. A total of 1,121 horses were examined from November 1998 to November 2000. Skin scrapings from 107 (9.5%) horses with signs of psoroptic mange resulted in 37 (34.6%) positive animals for Psoroptes equi. There was no statistical correlation between prevalence and host age or sex (c2, p>0,05). P. equi was diagnosed in animals with different hair color. The dorsal region (withers to hip) was the most affected area of the body.

• Psoroptes equi Acari Psoroptidae mange horses Brazil.

Abstract in Portuguese:

Tancredi M.G.F., Faccini J.L.H., Tancredi I.P., Martins I.V.F. & Scott F.B. 2005. [The host-relationship between Psoroptes equi and horses.] Relação parasito-hospedeiro entre Psoroptes equi e eqüinos. Pesquisa Veterinária Brasileira 25(4):207-209. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br Horses, abandoned by their owners (stray horses) along the main roads in the state of Rio de Janeiro, southeastern Brazil, and brought by the Federal Police to a quarantine station at the Universidade Federal Rural do Rio de Janeiro, were included in the study. A total of 1,121 horses were examined from November 1998 to November 2000. Skin scrapings from 107 (9.5%) horses with signs of psoroptic mange resulted in 37 (34.6%) positive animals for Psoroptes equi. There was no statistical correlation between prevalence and host age or sex (c2, p>0,05). P. equi was diagnosed in animals with different hair color. The dorsal region (withers to hip) was the most affected area of the body.