PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Moreira Souto M.A., Kommers G.D., Barros C.S.L., Piazer J.V.M., Rech R.R., Riet-Correa F. & Schild A.L. 2006. [Neoplasms of the upper digestive tract of cattle associated with spontaneous ingestion of bracken fern (Pteridium aquilinum).] Neoplasias do trato alimentar superior de bovinos associadas ao consumo espontâneo de samambaia (Pteridium aquilinum). Pesquisa Veterinária Brasileira 26(2):112-122. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: glaukommers@yahoo.com Thirty bovine with neoplasms of the upper digestive tract (UDT) associated with spontaneous ingestion of bracken fern (Pteridium aquilinum) were studied. They were from 27 farms, located in the municipalities of Jaguari (23) and Nova Esperança do Sul (4), Rio Grande do Sul, Brazil. The total cattle population in those farms was 1,090 and large amounts of bracken fern were found in the pastures. Twenty-six of the affected cattle were cows and four were castrated males, 3-13 years of age; most of them were 7-8 years old (46,6%). Clinical signs observed in the affected animals were progressive weight loss, absence of ruminal movements, cough, dysphagia, regurgitation, halitosis, diarrhea, and bloat. Less frequent signs were selective appetite, dyspnea, and salivation. Two bovine died and 28 were submitted to euthanasia in advanced stage of disease and necropsied. The main gross and microscopic alterations were found in identical areas of the UDT. They consisted of papillomas, transforming papillomas, and squamous cell carcinomas (SCCs). Metastases of SCCs to regional lymph nodes and other organs, such as liver and lungs, were also observed (18/30). Twenty-nine bovine had papillomas of various sizes in several areas of the UDT. The digestive papillomatosis ranged from mild (45%), to moderate (38%), to severe (17%). Three developing phases were observed microscopically in the examined papillomas: an early growing phase, a developing phase, and a regressing phase. In 16 cases, there was malignant transformation of papillomas into SCCs. The SCCs were solitary (12/30) or multiple (18/30) and were histologically well, moderately, or poorly differentiated. Grouping the distribution of SCCs of larger extension in the UDT into cranial region (base of the tongue, pharynx/oropharynx, and epiglottis), medial region (esophagus), and caudal region (cardia and rumen), the distribution was cranial in 39%, middle in 16%, and caudal in 45% of the cases. By the same grouping criteria, but considering the total number of times SCCs of varied extensions were diagnosed in the cranial, middle, and caudal regions, the percentages changed to 34%, 26%, and 40%, respectively. The epidemiological and histomorphological evidences found in this study are in agreement with the observations that point out the co-carcinogenesis between bovine papillomavirus type 4 infection and chemicals of bracken fern in the pathogenesis of the SCCs in the UDT of cattle. However, the presence of pre-neoplastic changes and SCCs in situ or in early stages of development, independently of the presence of papillomas, clearly indicates the possibility of development of SCCs from normal epithelium, probably due to the direct action of the chemical carcinogens contained in bracken fern.

• Poisonous plants Pteridium aquilinum plant poisoning bovine papillomavirus type 4 squamous cell carcinoma diseases of cattle pathology.

Abstract in Portuguese:

ABSTRACT.- Moreira Souto M.A., Kommers G.D., Barros C.S.L., Piazer J.V.M., Rech R.R., Riet-Correa F. & Schild A.L. 2006. [Neoplasms of the upper digestive tract of cattle associated with spontaneous ingestion of bracken fern (Pteridium aquilinum).] Neoplasias do trato alimentar superior de bovinos associadas ao consumo espontâneo de samambaia (Pteridium aquilinum). Pesquisa Veterinária Brasileira 26(2):112-122. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: glaukommers@yahoo.com Thirty bovine with neoplasms of the upper digestive tract (UDT) associated with spontaneous ingestion of bracken fern (Pteridium aquilinum) were studied. They were from 27 farms, located in the municipalities of Jaguari (23) and Nova Esperança do Sul (4), Rio Grande do Sul, Brazil. The total cattle population in those farms was 1,090 and large amounts of bracken fern were found in the pastures. Twenty-six of the affected cattle were cows and four were castrated males, 3-13 years of age; most of them were 7-8 years old (46,6%). Clinical signs observed in the affected animals were progressive weight loss, absence of ruminal movements, cough, dysphagia, regurgitation, halitosis, diarrhea, and bloat. Less frequent signs were selective appetite, dyspnea, and salivation. Two bovine died and 28 were submitted to euthanasia in advanced stage of disease and necropsied. The main gross and microscopic alterations were found in identical areas of the UDT. They consisted of papillomas, transforming papillomas, and squamous cell carcinomas (SCCs). Metastases of SCCs to regional lymph nodes and other organs, such as liver and lungs, were also observed (18/30). Twenty-nine bovine had papillomas of various sizes in several areas of the UDT. The digestive papillomatosis ranged from mild (45%), to moderate (38%), to severe (17%). Three developing phases were observed microscopically in the examined papillomas: an early growing phase, a developing phase, and a regressing phase. In 16 cases, there was malignant transformation of papillomas into SCCs. The SCCs were solitary (12/30) or multiple (18/30) and were histologically well, moderately, or poorly differentiated. Grouping the distribution of SCCs of larger extension in the UDT into cranial region (base of the tongue, pharynx/oropharynx, and epiglottis), medial region (esophagus), and caudal region (cardia and rumen), the distribution was cranial in 39%, middle in 16%, and caudal in 45% of the cases. By the same grouping criteria, but considering the total number of times SCCs of varied extensions were diagnosed in the cranial, middle, and caudal regions, the percentages changed to 34%, 26%, and 40%, respectively. The epidemiological and histomorphological evidences found in this study are in agreement with the observations that point out the co-carcinogenesis between bovine papillomavirus type 4 infection and chemicals of bracken fern in the pathogenesis of the SCCs in the UDT of cattle. However, the presence of pre-neoplastic changes and SCCs in situ or in early stages of development, independently of the presence of papillomas, clearly indicates the possibility of development of SCCs from normal epithelium, probably due to the direct action of the chemical carcinogens contained in bracken fern.

Abstract in English:

ABSTRACT.- Rissi D.R., Oliveira F.N., Rech R.R., Pierezan F., Lemos R.A.A. & Barros C.S.L. 2006. [Epidemiology, clinical signs and distribution of the encephalic lesions in cattle affected by meningoencephalitis caused by bovine herpesvirus-5.] Epidemiologia, sinais clínicos e distribuição das lesões encefálicas em bovinos afetados por meningoencefalite por herpesvírus bovino-5. Pesquisa Veterinária Brasileira 26(2):123-132. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Seven outbreaks and an isolated case of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5) in cattle in Rio Grande do Sul, Brazil, occurring in 2002-2004, are described. From a total population at risk of 1,359 cattle, 54 1-18-month-old calves from both sexes and several breeds were affected and 50 died spontaneously or were euthanatized while moribund. The highest frequency of cases was in recently weaned calves or calves submitted to other stressing factors. General rates of morbidity, mortality and lethality were respectively 3.97, 3.67 and 92.59%. Clinical courses varied from 3-10 days and included depression, nasal and ocular discharge, grinding of teeth, circling, blindness, fever, nistagmus, trembling, anorexia, dysphagia, drooling, incoordination, head pressing, rough hair coat, tachycardia, tachypnea, abdominal pain, melena, falls, recumbency, opisthotonus, convulsions and paddling. Nineteen calves were necropsied. Necropsy findings were characterized by hyperemia of leptomeninges, swollen rostral portions of the telencephalon, and flattening of frontal lobes gyri; frequently in these frontal areas there were segmental brown-yellow discoloration and softening (malacia) of the cortex. In cases with more protracted clinical courses there were extensive swelling, softening and hemorrhaging of the telencephalic frontal lobes. Microscopically, all affected cattle had a necrotizing non-suppurative meningoencephalitis with variable distribution among the 19 cases and among the various telencephalic regions of the same case. The severity of these changes were more marked, in decreasing order of intensity, in the telencephalic frontal cortex, basal ganglia (nuclei), thalamus, brain stem, parietal telencephalic cortex, occipital telencephalic cortex and cerebellum. Perivascular inflammatory infiltrate consisted predominantly of lymphocytes, plasm cells, and less frequently of neutrophils. Additional microscopic findings included variable degrees of gliosis, edema, neuronal necrosis in the telencephalic cortex characterized by shrinking and eosinophilia of perikaria and nuclear picnosis (red neuron); basophilic intranuclear inclusion bodies in astrocytes and neurons (21.05% of the cases); sattelitosis; and neuronophagia. The areas of softening in the cortical substance consisted of necrosis of the neuroctodermal elements with maintenance of mesenchymal structures (vessels and microglia), infiltrate of Gitter cells, and, in more severe cases, extensive hemorrhages. In chronic cases, only vascular structures and a few Gitter cells remained in the cortical area leaving a cavity between white matter and leptomeninges (residual lesion).

• Bovine herpesvirus-5 BoHV-5 encephalitis diseases of cattle viral diseases neuropathology.

Abstract in Portuguese:

ABSTRACT.- Rissi D.R., Oliveira F.N., Rech R.R., Pierezan F., Lemos R.A.A. & Barros C.S.L. 2006. [Epidemiology, clinical signs and distribution of the encephalic lesions in cattle affected by meningoencephalitis caused by bovine herpesvirus-5.] Epidemiologia, sinais clínicos e distribuição das lesões encefálicas em bovinos afetados por meningoencefalite por herpesvírus bovino-5. Pesquisa Veterinária Brasileira 26(2):123-132. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Seven outbreaks and an isolated case of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5) in cattle in Rio Grande do Sul, Brazil, occurring in 2002-2004, are described. From a total population at risk of 1,359 cattle, 54 1-18-month-old calves from both sexes and several breeds were affected and 50 died spontaneously or were euthanatized while moribund. The highest frequency of cases was in recently weaned calves or calves submitted to other stressing factors. General rates of morbidity, mortality and lethality were respectively 3.97, 3.67 and 92.59%. Clinical courses varied from 3-10 days and included depression, nasal and ocular discharge, grinding of teeth, circling, blindness, fever, nistagmus, trembling, anorexia, dysphagia, drooling, incoordination, head pressing, rough hair coat, tachycardia, tachypnea, abdominal pain, melena, falls, recumbency, opisthotonus, convulsions and paddling. Nineteen calves were necropsied. Necropsy findings were characterized by hyperemia of leptomeninges, swollen rostral portions of the telencephalon, and flattening of frontal lobes gyri; frequently in these frontal areas there were segmental brown-yellow discoloration and softening (malacia) of the cortex. In cases with more protracted clinical courses there were extensive swelling, softening and hemorrhaging of the telencephalic frontal lobes. Microscopically, all affected cattle had a necrotizing non-suppurative meningoencephalitis with variable distribution among the 19 cases and among the various telencephalic regions of the same case. The severity of these changes were more marked, in decreasing order of intensity, in the telencephalic frontal cortex, basal ganglia (nuclei), thalamus, brain stem, parietal telencephalic cortex, occipital telencephalic cortex and cerebellum. Perivascular inflammatory infiltrate consisted predominantly of lymphocytes, plasm cells, and less frequently of neutrophils. Additional microscopic findings included variable degrees of gliosis, edema, neuronal necrosis in the telencephalic cortex characterized by shrinking and eosinophilia of perikaria and nuclear picnosis (red neuron); basophilic intranuclear inclusion bodies in astrocytes and neurons (21.05% of the cases); sattelitosis; and neuronophagia. The areas of softening in the cortical substance consisted of necrosis of the neuroctodermal elements with maintenance of mesenchymal structures (vessels and microglia), infiltrate of Gitter cells, and, in more severe cases, extensive hemorrhages. In chronic cases, only vascular structures and a few Gitter cells remained in the cortical area leaving a cavity between white matter and leptomeninges (residual lesion).

Abstract in English:

Corrêa A.M.R., Pescador C.A., Schmitz M., Zlotowski P., Rozza D.B., Oliveira E.C., Barcellos D.E. & Driemeier D. 2006. [Clinical and pathological aspects of swine circovirosis in Rio Grande do Sul, southern Brazil.] Aspectos clínico-patológicos associados à circovirose suína no Rio Grande do Sul. Pesquisa Veterinária Brasileira 26(1):9-13. Setor de Patologia Veterinária, Faculdade de Veterinária, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br A total of 97 pigs, which had presented wasting, lymphadenomegaly, respiratory distress and pale or icteric mucosa, was necropsied over a 6-month period. Macroscopic lesions were characterized mostly by enlarged lymph nodes, non collapsed and round edged lungs with cranio-ventral areas of consolidation and interlobular edema. Kidneys had increased size, were pale, and presented numerous scattered white spots projecting from surface to the cortical area. Some kidneys also showed small red spots similar to petechial hemorrhage over the cortex. Main microscopic lesions were lympho-histiocytic infiltration in lymph nodes, lungs, and kidneys. Immunohistochemical probing with polyclonal antisera to type II swine circovirus stained positively in 50 out of the 56 cases tested (89.2%).

• Circovirus PMWS PCV2 immunohistochemistry swine.

Abstract in Portuguese:

Corrêa A.M.R., Pescador C.A., Schmitz M., Zlotowski P., Rozza D.B., Oliveira E.C., Barcellos D.E. & Driemeier D. 2006. [Clinical and pathological aspects of swine circovirosis in Rio Grande do Sul, southern Brazil.] Aspectos clínico-patológicos associados à circovirose suína no Rio Grande do Sul. Pesquisa Veterinária Brasileira 26(1):9-13. Setor de Patologia Veterinária, Faculdade de Veterinária, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br A total of 97 pigs, which had presented wasting, lymphadenomegaly, respiratory distress and pale or icteric mucosa, was necropsied over a 6-month period. Macroscopic lesions were characterized mostly by enlarged lymph nodes, non collapsed and round edged lungs with cranio-ventral areas of consolidation and interlobular edema. Kidneys had increased size, were pale, and presented numerous scattered white spots projecting from surface to the cortical area. Some kidneys also showed small red spots similar to petechial hemorrhage over the cortex. Main microscopic lesions were lympho-histiocytic infiltration in lymph nodes, lungs, and kidneys. Immunohistochemical probing with polyclonal antisera to type II swine circovirus stained positively in 50 out of the 56 cases tested (89.2%).

Abstract in English:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

• Listeria sp Listeria monocytogenes listeriosis encephalitis immunohistochemistry pathology diseases of goats.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

Abstract in English:

Rozza D.B., Raymundo D.L., Corrêa A.M.R., Seitz A.L., Driemeier D. & Colodel E.M. 2006. [Spontaneous Baccharis coridifolia (Compositae) poisoning in sheep.] Intoxicação espontânea por Baccharis coridifolia (Compositae) em ovinos. Pesquisa Veterinária Brasileira 26(1):21-25. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br An outbreak of Baccharis coridifolia (Compositae) poisoning in sheep is reported, which occurred in November 2004 in the county of Caxias do Sul, Rio Grande do Sul (RS), southern Brazil. From a herd of 212 sheep, coming from a Baccharis coridifolia free area, in the county of Jaguarão, RS, 35 sheep died until 5 days after the arrival in the new area where the plant was found with abundance. The clinical signs began 8 hours after introduction of the animals into the new pasture and included apathy, anorexia, abdominal retraction or mild distension, weakness of hind limbs, dry feces, sternal ou lateral decumbency, struggling movements, coma and death. Clinical evolution was from 5 to 48 hours. Other sheep that were already before on the pasture were not affected. Main necropsy findings were in the gastrointestinal tube, with wall and serosal oedema, mainly in the reticulo-ruminal fold and of the abomasum, reddening and detachment of the mucosa of forestomachs, and intense hemorrhage in the submucosa. Histopathological findings were degeneration and necrosis of the epithelium of the forestomachs with polymorphonuclear infiltration associated with bacterial colonies, congestion, hemorrhage and oedema, and lymphoid tissue necrosis.

• Poisonous plants Baccharis coridifolia Compositae plant poisoning diseases of sheep pathology.

Abstract in Portuguese:

Rozza D.B., Raymundo D.L., Corrêa A.M.R., Seitz A.L., Driemeier D. & Colodel E.M. 2006. [Spontaneous Baccharis coridifolia (Compositae) poisoning in sheep.] Intoxicação espontânea por Baccharis coridifolia (Compositae) em ovinos. Pesquisa Veterinária Brasileira 26(1):21-25. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br An outbreak of Baccharis coridifolia (Compositae) poisoning in sheep is reported, which occurred in November 2004 in the county of Caxias do Sul, Rio Grande do Sul (RS), southern Brazil. From a herd of 212 sheep, coming from a Baccharis coridifolia free area, in the county of Jaguarão, RS, 35 sheep died until 5 days after the arrival in the new area where the plant was found with abundance. The clinical signs began 8 hours after introduction of the animals into the new pasture and included apathy, anorexia, abdominal retraction or mild distension, weakness of hind limbs, dry feces, sternal ou lateral decumbency, struggling movements, coma and death. Clinical evolution was from 5 to 48 hours. Other sheep that were already before on the pasture were not affected. Main necropsy findings were in the gastrointestinal tube, with wall and serosal oedema, mainly in the reticulo-ruminal fold and of the abomasum, reddening and detachment of the mucosa of forestomachs, and intense hemorrhage in the submucosa. Histopathological findings were degeneration and necrosis of the epithelium of the forestomachs with polymorphonuclear infiltration associated with bacterial colonies, congestion, hemorrhage and oedema, and lymphoid tissue necrosis.

Abstract in English:

Batista J.S., Riet-Correa F., Barbosa R.C. & Guerra J.L. 2006. [Experimental infection by Trypanosoma vivax in sheep.] Infecção experimental por Trypanosoma vivax em ovinos. Pesquisa Veterinária Brasileira 26(1):31-37. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br This paper has the objective to report clinical signs, hematologic changes, and macroscopic and microscopic alterations in sheep infected experimentally with Trypanosoma vivax, isolated from an outbreak in cattle in the semiarid region of the state of Paraíba, northeastern Brazil. Four Santa Inês sheep were inoculated intravenously with 1ml of blood containing 1.85x105 trypomastigotes. Other 4 sheep were used as control. The presence of trypanosomes in the blood and the temperature were recorded daily during the first 30 days and fortnightly from day 31 to day 90 after infection. Also fortnightly, the sheep were weighed and blood samples were obtained for hematological analysis. One inoculated sheep died 75 days after inoculation. The other 3 inoculated and the 4 control sheep were killed 90 days after the beginning of the experiment. T. vivax was observed constantly in the blood of the inoculated sheep from 4-15 days after inoculation. From day 16 to day 30 the parasitemia was lower and irregular. No trypanosomes were observed in the blood after 30 days of infection. A positive linear correlation [Y=0.027x + 38.515, R2=0.944 (P<0.05)] was found between the number of trypanosomes in the blood and body temperature. Significant differences were observed in body weight between inoculated and non-inoculated sheep from day 30 to day 90 after the experiment. From day 30 to day 90 after inoculation trypanosomes were absent or only in low numbers in the blood, and the animals showed anemia and leucopenia. Gross alterations were pale carcasses, enlarged lymph nodes and spleen, and augmented liquid in the peritoneal and pericardiac cavities. Multifocal lymphocytic myocarditis was observed histologically. It is concluded that the isolate is pathogenic to sheep. It is suggested that the semiarid region, where the outbreak occurred, is non-endemic (marginal) for trypanosomosis, and that the disease may occur if the parasite is introduced through vectors.

• Experimental infection Trypanosoma vivax sheep semiarid.

Abstract in Portuguese:

Batista J.S., Riet-Correa F., Barbosa R.C. & Guerra J.L. 2006. [Experimental infection by Trypanosoma vivax in sheep.] Infecção experimental por Trypanosoma vivax em ovinos. Pesquisa Veterinária Brasileira 26(1):31-37. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br This paper has the objective to report clinical signs, hematologic changes, and macroscopic and microscopic alterations in sheep infected experimentally with Trypanosoma vivax, isolated from an outbreak in cattle in the semiarid region of the state of Paraíba, northeastern Brazil. Four Santa Inês sheep were inoculated intravenously with 1ml of blood containing 1.85x105 trypomastigotes. Other 4 sheep were used as control. The presence of trypanosomes in the blood and the temperature were recorded daily during the first 30 days and fortnightly from day 31 to day 90 after infection. Also fortnightly, the sheep were weighed and blood samples were obtained for hematological analysis. One inoculated sheep died 75 days after inoculation. The other 3 inoculated and the 4 control sheep were killed 90 days after the beginning of the experiment. T. vivax was observed constantly in the blood of the inoculated sheep from 4-15 days after inoculation. From day 16 to day 30 the parasitemia was lower and irregular. No trypanosomes were observed in the blood after 30 days of infection. A positive linear correlation [Y=0.027x + 38.515, R2=0.944 (P<0.05)] was found between the number of trypanosomes in the blood and body temperature. Significant differences were observed in body weight between inoculated and non-inoculated sheep from day 30 to day 90 after the experiment. From day 30 to day 90 after inoculation trypanosomes were absent or only in low numbers in the blood, and the animals showed anemia and leucopenia. Gross alterations were pale carcasses, enlarged lymph nodes and spleen, and augmented liquid in the peritoneal and pericardiac cavities. Multifocal lymphocytic myocarditis was observed histologically. It is concluded that the isolate is pathogenic to sheep. It is suggested that the semiarid region, where the outbreak occurred, is non-endemic (marginal) for trypanosomosis, and that the disease may occur if the parasite is introduced through vectors.

Abstract in English:

Gomes M., Uieda W. & Latorre M.R.D.O. 2006. [Influence of sex differences in the same colony for chemical control of vampire Desmodus rotundus (Phyllostomidae) populations in the state of São Paulo, Brazil.] Influência do sexo de indivíduos da mesma colônia no controle químico das populações do morcego hematófago Desmodus rotundus (Phyllstomidae) no Estado de São Paulo. Pesquisa Veterinária Brasileira 26(1):38-43. Coordenadoria de Defesa Agropecuária/SP, Regional Mogi das Cruzes, Av. Cândido X.A.Sousa 35, Mogi das Cruzes, SP 08780-210, Brazil. E-mail: murilong@usp.br The aim of this study was to verify the fidelity to the diurnal roosts by the genders of the vampire bat Desmodus rotundus, and to analyse the Warfarin gel 2% effectiveness for reduction of the size of vampire bat colonies, when individuals of different sexes were treated. In 1999 and 2000, 626 vampire bats were mist netted while leaving at night 12 diurnal roosts in the state of São Paulo. They were marked, and 10% of the roost population received the Warfarin gel 2% treatment. In Test I only males were treated, in Test II only females were treated, and in Test III 5% of males and females were treated. After 5 and 10 days, the dead and the survivors were counted. Females were more loyal to the roosts (p<0,01) and better wide spreader of the Warfarin gel (p<0,01).

• Rabies vampire bats Desmodus rotundus Warfarin gel.

Abstract in Portuguese:

Gomes M., Uieda W. & Latorre M.R.D.O. 2006. [Influence of sex differences in the same colony for chemical control of vampire Desmodus rotundus (Phyllostomidae) populations in the state of São Paulo, Brazil.] Influência do sexo de indivíduos da mesma colônia no controle químico das populações do morcego hematófago Desmodus rotundus (Phyllstomidae) no Estado de São Paulo. Pesquisa Veterinária Brasileira 26(1):38-43. Coordenadoria de Defesa Agropecuária/SP, Regional Mogi das Cruzes, Av. Cândido X.A.Sousa 35, Mogi das Cruzes, SP 08780-210, Brazil. E-mail: murilong@usp.br The aim of this study was to verify the fidelity to the diurnal roosts by the genders of the vampire bat Desmodus rotundus, and to analyse the Warfarin gel 2% effectiveness for reduction of the size of vampire bat colonies, when individuals of different sexes were treated. In 1999 and 2000, 626 vampire bats were mist netted while leaving at night 12 diurnal roosts in the state of São Paulo. They were marked, and 10% of the roost population received the Warfarin gel 2% treatment. In Test I only males were treated, in Test II only females were treated, and in Test III 5% of males and females were treated. After 5 and 10 days, the dead and the survivors were counted. Females were more loyal to the roosts (p<0,01) and better wide spreader of the Warfarin gel (p<0,01).

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:

Lima E.F., Riet-Correa F., Castro R.S., Gomes A.A.B. & Lima F.S. 2005. [Clinical signs, distribution of the lesions in the central nervous system and epidemiology of rabies in northeastern Brazil.] Sinais clínicos, distribuição das lesões no sistema nervoso e epidemiologia da raiva em herbívoros na região Nordeste do Brasil. Pesquisa Veterinária Brasileira 25(4):250-264. Centro de Saúde e Tecnologia Rural, Campus de Patos, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: riet@cstr.ufcg.br Twenty four outbreaks of rabies in cattle, 4 in horses, 2 in sheep, and 2 in goats are reported in northeastern Brazil. All outbreaks occurred in the state of Paraíba, except one in horses that occurred in the state of Rio Grande do Norte. All outbreaks, except one in sheep, were probably transmitted by vampire-bats, but the transmission by foxes (Dusicyon vetulus) is also possible. Clinical signs were characteristic for distribution of the lesions in the central nervous system (CNS). In cattle, signs were mainly of the paralytic form of rabies, caused by lesions on the spinal cord, brain stem and cerebellum; but some animals showed also depression, excitation and other signs due to cerebral lesions. In 3 out of 5 horses, the main clinical signs were due to lesions in the cerebrum, and 2 had the paralytic form. From 4 sheep and 2 goats affected, 4 showed clinical signs of the paralytic form; but in 1 goat and 1 sheep the main clinical signs were caused by cerebral lesions. All affected animals, except 1 goat, had a clinical manifestation period of 2-8 days. The only gross lesions were distention of the urinary bladder in 4 cattle and distention of the rectum in 2 others. Two horses had skin lesions due to traumatic injury. Histologic lesions were diffuse non-suppurative encephalomyelitis and meningitis. In the horses, and in one goat with a clinical manifestation period of 35 days, the lesions were more severe, with neuronal necrosis, neuronophagia, and presence of axonal spheroids. Negri bodies were found in 87% (20/23) of the cattle cases examined histologically. In small ruminants Negri bodies were found in 83% (5/6) of the cases. In sheep, goats and cattle, Negri bodies were more frequent in the cerebellum, but they were found also in brain stem, spinal cord and cerebrum. In horses, Negri bodies were found in small amounts only in the cortex of one animal, and in the cortex and hippocampus of another. Histologic lesions and Negri bodies in the trigeminal ganglia were less frequent than in the CNS. These results show that in rabies of herbivores, clinical signs and distribution of lesions in the CNS are variable, so that for the diagnosis and adequate clinical evaluation and the histologic study of different areas of the CNS are necessary. This also suggests that when the fluorescent antibody test and mouse inoculation test are negative, they should be repeated with samples from different areas of the brain and spinal cord. Frequency data of diseases from 4 diagnostic laboratories were used to estimate cattle deaths due to rabies in 3 Brazilian states. In Paraíba, with a population of 918,262 cattle, the annual death rate is estimated in 8,609 heads. In Mato Grosso do Sul, with a population of 23 millions cattle, deaths caused by rabies are estimated in 149,500 heads, and in Rio Grande do Sul, with a cattle population of 13 millions, cattle deaths due to rabies are estimated in 13,000 to 16,250 heads. If these data are used to estimate cattle losses in Brazil, with a cattle population of 195 millions, it can be estimated that 842,688 deaths are caused annually by rabies.

• Rabies cattle sheep goats horses pathology clinical signs economical impact.

Abstract in Portuguese:

Lima E.F., Riet-Correa F., Castro R.S., Gomes A.A.B. & Lima F.S. 2005. [Clinical signs, distribution of the lesions in the central nervous system and epidemiology of rabies in northeastern Brazil.] Sinais clínicos, distribuição das lesões no sistema nervoso e epidemiologia da raiva em herbívoros na região Nordeste do Brasil. Pesquisa Veterinária Brasileira 25(4):250-264. Centro de Saúde e Tecnologia Rural, Campus de Patos, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: riet@cstr.ufcg.br Twenty four outbreaks of rabies in cattle, 4 in horses, 2 in sheep, and 2 in goats are reported in northeastern Brazil. All outbreaks occurred in the state of Paraíba, except one in horses that occurred in the state of Rio Grande do Norte. All outbreaks, except one in sheep, were probably transmitted by vampire-bats, but the transmission by foxes (Dusicyon vetulus) is also possible. Clinical signs were characteristic for distribution of the lesions in the central nervous system (CNS). In cattle, signs were mainly of the paralytic form of rabies, caused by lesions on the spinal cord, brain stem and cerebellum; but some animals showed also depression, excitation and other signs due to cerebral lesions. In 3 out of 5 horses, the main clinical signs were due to lesions in the cerebrum, and 2 had the paralytic form. From 4 sheep and 2 goats affected, 4 showed clinical signs of the paralytic form; but in 1 goat and 1 sheep the main clinical signs were caused by cerebral lesions. All affected animals, except 1 goat, had a clinical manifestation period of 2-8 days. The only gross lesions were distention of the urinary bladder in 4 cattle and distention of the rectum in 2 others. Two horses had skin lesions due to traumatic injury. Histologic lesions were diffuse non-suppurative encephalomyelitis and meningitis. In the horses, and in one goat with a clinical manifestation period of 35 days, the lesions were more severe, with neuronal necrosis, neuronophagia, and presence of axonal spheroids. Negri bodies were found in 87% (20/23) of the cattle cases examined histologically. In small ruminants Negri bodies were found in 83% (5/6) of the cases. In sheep, goats and cattle, Negri bodies were more frequent in the cerebellum, but they were found also in brain stem, spinal cord and cerebrum. In horses, Negri bodies were found in small amounts only in the cortex of one animal, and in the cortex and hippocampus of another. Histologic lesions and Negri bodies in the trigeminal ganglia were less frequent than in the CNS. These results show that in rabies of herbivores, clinical signs and distribution of lesions in the CNS are variable, so that for the diagnosis and adequate clinical evaluation and the histologic study of different areas of the CNS are necessary. This also suggests that when the fluorescent antibody test and mouse inoculation test are negative, they should be repeated with samples from different areas of the brain and spinal cord. Frequency data of diseases from 4 diagnostic laboratories were used to estimate cattle deaths due to rabies in 3 Brazilian states. In Paraíba, with a population of 918,262 cattle, the annual death rate is estimated in 8,609 heads. In Mato Grosso do Sul, with a population of 23 millions cattle, deaths caused by rabies are estimated in 149,500 heads, and in Rio Grande do Sul, with a cattle population of 13 millions, cattle deaths due to rabies are estimated in 13,000 to 16,250 heads. If these data are used to estimate cattle losses in Brazil, with a cattle population of 195 millions, it can be estimated that 842,688 deaths are caused annually by rabies.