PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Soares M.P., Quevedo P.S. & Schild A.L. 2008. [Perreyia flavipes larvae poisoning in cattle in southern Rio Grande do Sul, Brazil.] Intoxicação por larvas de Perreyia flavipes em bovinos na região sul do Rio Grande do Sul. Pesquisa Veterinária Brasileira 28(3):169-173. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br Three outbreaks of poisoning by Perreyia flavipes Konow, 1899 (Hymenoptera: Pergidae) in cattle during July and August 2006 in southern Brazil are reported. The morbidity rate was 0.8%, 6.2% and 33% on the 3 farms, respectively. Fatality rate was 100%. Clinical signs were depression, jaundice, recumbence, pedaling movements and death in 24-48 hours. The liver was enlarged with increased lobular pattern, the mesenteric lymph nodes were edematous and Peyer patches of the small gut were depressed. Petechial hemorrhages and ecchymosis were observed in the mesentery and abomasum. On histologic examination the liver showed centrolobular or massive necrosis. Hemosiderosis and necrosis of the germinative centers of lymph nodes, white pulp of the spleen and Peyer patches were also observed. The poisoning occurred probably due to an intense drought in October-December 2005, when the insect stayed as a cocoon underground. The dry conditions probably avoided a higher number of adult sawflies to emerge from the cocoons, what resulted in greater egg production. The large amount of decaying grass due to almost normal rain fall during summer seemed to have provided favorable environmental conditions for the development of larvae in winter.

• Perreyia flavipes sawfly epidemiology bovine hepatic necrosis

Abstract in Portuguese:

ABSTRACT.- Soares M.P., Quevedo P.S. & Schild A.L. 2008. [Perreyia flavipes larvae poisoning in cattle in southern Rio Grande do Sul, Brazil.] Intoxicação por larvas de Perreyia flavipes em bovinos na região sul do Rio Grande do Sul. Pesquisa Veterinária Brasileira 28(3):169-173. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br Three outbreaks of poisoning by Perreyia flavipes Konow, 1899 (Hymenoptera: Pergidae) in cattle during July and August 2006 in southern Brazil are reported. The morbidity rate was 0.8%, 6.2% and 33% on the 3 farms, respectively. Fatality rate was 100%. Clinical signs were depression, jaundice, recumbence, pedaling movements and death in 24-48 hours. The liver was enlarged with increased lobular pattern, the mesenteric lymph nodes were edematous and Peyer patches of the small gut were depressed. Petechial hemorrhages and ecchymosis were observed in the mesentery and abomasum. On histologic examination the liver showed centrolobular or massive necrosis. Hemosiderosis and necrosis of the germinative centers of lymph nodes, white pulp of the spleen and Peyer patches were also observed. The poisoning occurred probably due to an intense drought in October-December 2005, when the insect stayed as a cocoon underground. The dry conditions probably avoided a higher number of adult sawflies to emerge from the cocoons, what resulted in greater egg production. The large amount of decaying grass due to almost normal rain fall during summer seemed to have provided favorable environmental conditions for the development of larvae in winter.

Abstract in English:

ABSTRACT.- Rodrigues A., De La Corte F.D., Graça D.L., Rissi D.R., Schild A.L., Kommers G.D. & Barros C.S.L. 2008. [Stringhalt in horses from the state of Rio Grande do Sul, Brazil.] Harpejamento em eqüinos no Rio Grande do Sul. Pesquisa Veterinária Brasileira 28(1):23-28. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical, gross and histological findings of cases of stringhalt occurring in horses from eight farms in six counties in the State of Rio Grande do Sul, Brazil from 2000-2005 are reported. At least 10 horses were affected. Ages of affected horses were 1-13 years (average 6.2 years) and 1-2 horses were affected in each farm. Factors that might have influenced the appearance of the disease included dearth of forage due to insufficient rainfall. The presence of the plant Hypochaeris radicata, often implicated as a cause of stringhalt in horses, was observed in the pasture of three out of five evaluated farms and in six of these farms the pasture was poor due to scarse precipitation. Estimated morbidity was 17.3% and lethality was close to zero although two horses were euthanatized for necropsy. Characteristic clinical signs included excessive flexion of the stifle and hock joints, impaired ambulation and bunny hop-type of gait. Clinical disease was graded by number scores from 1-5, higher numbers indicating increasing severity. Three horses were graded as 1, one horse as 2, three horses as 3, one horse as 4 and two horses as 5. Treatment with phenytoin in two horses and with phenytoin and tenectomy in another one did not result in amelioration of the clinical signs. Four out of ten clinical examined horses with stringhalt recovered with no treatment within 2-4 months of clinical disease and four affected horses did not recover even after 9-17 months of clinical disease, when they were lastly examined. Necropsy findings included atrophy of skeletal muscle of the large muscular groups which was confirmed histologically. Histological evaluation of peripheral nerves of one of the euthanatized horses revealed reduction or absence of myelinated fibers. Ultrastructural findings included signs of demyelination, regeneration and remyelination of peripheral nerves.

• Neuropathy toxic neuropathy diseases of horses

Abstract in Portuguese:

ABSTRACT.- Rodrigues A., De La Corte F.D., Graça D.L., Rissi D.R., Schild A.L., Kommers G.D. & Barros C.S.L. 2008. [Stringhalt in horses from the state of Rio Grande do Sul, Brazil.] Harpejamento em eqüinos no Rio Grande do Sul. Pesquisa Veterinária Brasileira 28(1):23-28. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical, gross and histological findings of cases of stringhalt occurring in horses from eight farms in six counties in the State of Rio Grande do Sul, Brazil from 2000-2005 are reported. At least 10 horses were affected. Ages of affected horses were 1-13 years (average 6.2 years) and 1-2 horses were affected in each farm. Factors that might have influenced the appearance of the disease included dearth of forage due to insufficient rainfall. The presence of the plant Hypochaeris radicata, often implicated as a cause of stringhalt in horses, was observed in the pasture of three out of five evaluated farms and in six of these farms the pasture was poor due to scarse precipitation. Estimated morbidity was 17.3% and lethality was close to zero although two horses were euthanatized for necropsy. Characteristic clinical signs included excessive flexion of the stifle and hock joints, impaired ambulation and bunny hop-type of gait. Clinical disease was graded by number scores from 1-5, higher numbers indicating increasing severity. Three horses were graded as 1, one horse as 2, three horses as 3, one horse as 4 and two horses as 5. Treatment with phenytoin in two horses and with phenytoin and tenectomy in another one did not result in amelioration of the clinical signs. Four out of ten clinical examined horses with stringhalt recovered with no treatment within 2-4 months of clinical disease and four affected horses did not recover even after 9-17 months of clinical disease, when they were lastly examined. Necropsy findings included atrophy of skeletal muscle of the large muscular groups which was confirmed histologically. Histological evaluation of peripheral nerves of one of the euthanatized horses revealed reduction or absence of myelinated fibers. Ultrastructural findings included signs of demyelination, regeneration and remyelination of peripheral nerves.

Abstract in English:

ABSTRACT.- Schons S.V., Kommers G.D., Pereira G.M., Raffi M.B. & Schild A.L. 2007. [Microscopic, immunohistochemical, and ultra-structural study of the lesions experimentaly induced by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Estudo histológico, imuno-histoquímico e ultra-estrutural das lesões induzidas experimentalmente por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 27(7):269-276. Laboratório Regional de Diagnóstico, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br The objective of this study was to investigate the pathogenesis of the lesions observed in cattle experimentally poisoned by Ramaria flavo-brunnescens. The mushroom was given to three 9 to10-month-old Jersey calves immediately after harvesting. Daily doses were around 20g/kg of body weight during 7 (Calf 1) or 13 days (Calves 2-3), and the total doses of mushroom given were 140, 268, and 261g/kg of body weight, respectively. One calf (Calf 4) with same age and breed was used as control. Clinical signs were characterized by prostration, anorexia, hyperemia of oral mucosa, and loosening of long hairs of the tail tip under mild traction. The calves were submitted to euthanasia and necropsied on days 8 (Calf 1) and 15 (Calves 2-4) after the beginning of the experiment. Microscopically, there was smoothness of dorsal epithelium of tongue with absence of filiform papillae, vacuolation of keratinocytes, and loosening of the keratin layer. In the hooves, there was vacuolation and irregular keratinization of the laminar epidermis and hyperplasia of keratinocytes. Hyperkeratosis, vacuolation of the external root sheath, thickening of tricholemal keratin, and inflammatory infiltration around hair follicles were observed on the skin of the tail tip. Immunohistochemical results with anti-pancytoceratin and anti-Ki67 (cell proliferation marker) antibodies showed no differences between the tongue dorsal epithelium of the control and experimental calves. Ultrastructural study demonstrated decrease in tonofilaments and increased intercellular spaces of the spinous layer of the tongue dorsal epithelium. The results of this study favor the hypothesis of an interference with the epithelial keratinization mechanisms by the toxic principles of Ramaria flavo-brunnescens.

• Ramaria flavo-brunnecens mushroom poisoning cattle diseases pathology

Abstract in Portuguese:

ABSTRACT.- Schons S.V., Kommers G.D., Pereira G.M., Raffi M.B. & Schild A.L. 2007. [Microscopic, immunohistochemical, and ultra-structural study of the lesions experimentaly induced by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Estudo histológico, imuno-histoquímico e ultra-estrutural das lesões induzidas experimentalmente por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 27(7):269-276. Laboratório Regional de Diagnóstico, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br The objective of this study was to investigate the pathogenesis of the lesions observed in cattle experimentally poisoned by Ramaria flavo-brunnescens. The mushroom was given to three 9 to10-month-old Jersey calves immediately after harvesting. Daily doses were around 20g/kg of body weight during 7 (Calf 1) or 13 days (Calves 2-3), and the total doses of mushroom given were 140, 268, and 261g/kg of body weight, respectively. One calf (Calf 4) with same age and breed was used as control. Clinical signs were characterized by prostration, anorexia, hyperemia of oral mucosa, and loosening of long hairs of the tail tip under mild traction. The calves were submitted to euthanasia and necropsied on days 8 (Calf 1) and 15 (Calves 2-4) after the beginning of the experiment. Microscopically, there was smoothness of dorsal epithelium of tongue with absence of filiform papillae, vacuolation of keratinocytes, and loosening of the keratin layer. In the hooves, there was vacuolation and irregular keratinization of the laminar epidermis and hyperplasia of keratinocytes. Hyperkeratosis, vacuolation of the external root sheath, thickening of tricholemal keratin, and inflammatory infiltration around hair follicles were observed on the skin of the tail tip. Immunohistochemical results with anti-pancytoceratin and anti-Ki67 (cell proliferation marker) antibodies showed no differences between the tongue dorsal epithelium of the control and experimental calves. Ultrastructural study demonstrated decrease in tonofilaments and increased intercellular spaces of the spinous layer of the tongue dorsal epithelium. The results of this study favor the hypothesis of an interference with the epithelial keratinization mechanisms by the toxic principles of Ramaria flavo-brunnescens.

Abstract in English:

ABSTRACT.- Sant’Ana F.J.F., Garcia E.C., Rabelo R.E., Costa Y.L., Schild A.L. & Riet-Correa F. 2007. [Oropharyngeal and neurologic lesions in sheep associated with the use of drenching guns.] Lesões orofaríngeas e neurológicas em ovinos associadas ao uso de pistolas dosificadoras. Pesquisa Veterinária Brasileira 27(7):282-286. Laboratório de Patologia Veterinária, Universidade Federal de Goiás, Campus Jataí, 75800-000 Jataí, GO, Brazil. E-mail: santanafjf@yahoo.com Six outbreaks of oropharyngeal lesions caused by drenching guns in sheep are reported. In 2 outbreaks in Rio Grande do Sul the morbidity was 6.25% and 15%, and the lesions observed after antihelmintic treatment in adult sheep were characterized by a fistula extending from mouth to skin of the face. All sheep died or were euthanatized after continuous weight loss for up to 8 months. Another outbreak in the same State affected 26 out of 360 adult sheep after being dosed with molasses, causing lesions in the oral mucosa followed by malignant edema of the oral and subcutaneous tissues. All sheep died within 10 days after treatment. Another case observed in Rio Grande do Sul affected one out of 88 adult ewes. The animal died with hemorrhages from the nose and mouth 8 days after antihelmintic treatment. At necropsy an ulcerated lesion covered by a clot of fibrine was found in the oral mucosa. The lesion had a fistulated tract with purulent exudate extending through the soft tissues in direction to the right eye. Two outbreaks occurred in the State of Goiás 16-20 days after antihelmintic treatment in 5-9 months old lambs. Morbidity was 11.43% and 15.62% and fatality rate was 7.14% and 9.38%. Main clinical signs were nervous signs caused by abscesses with a diameter of 0.5-3cm, containing purulent exudates in the oropharynx, soft palate and adjacent muscles extending to the meninges through the atlantoaxial joint. Not-purulent meningitis was observed histologically. The need to use proper drenching guns and pay attention during dosing to avoid lesions of the oropharynx is pointed out.

• Oropharyngeal abscess neurologic alterations drenching guns sheep

Abstract in Portuguese:

ABSTRACT.- Sant’Ana F.J.F., Garcia E.C., Rabelo R.E., Costa Y.L., Schild A.L. & Riet-Correa F. 2007. [Oropharyngeal and neurologic lesions in sheep associated with the use of drenching guns.] Lesões orofaríngeas e neurológicas em ovinos associadas ao uso de pistolas dosificadoras. Pesquisa Veterinária Brasileira 27(7):282-286. Laboratório de Patologia Veterinária, Universidade Federal de Goiás, Campus Jataí, 75800-000 Jataí, GO, Brazil. E-mail: santanafjf@yahoo.com Six outbreaks of oropharyngeal lesions caused by drenching guns in sheep are reported. In 2 outbreaks in Rio Grande do Sul the morbidity was 6.25% and 15%, and the lesions observed after antihelmintic treatment in adult sheep were characterized by a fistula extending from mouth to skin of the face. All sheep died or were euthanatized after continuous weight loss for up to 8 months. Another outbreak in the same State affected 26 out of 360 adult sheep after being dosed with molasses, causing lesions in the oral mucosa followed by malignant edema of the oral and subcutaneous tissues. All sheep died within 10 days after treatment. Another case observed in Rio Grande do Sul affected one out of 88 adult ewes. The animal died with hemorrhages from the nose and mouth 8 days after antihelmintic treatment. At necropsy an ulcerated lesion covered by a clot of fibrine was found in the oral mucosa. The lesion had a fistulated tract with purulent exudate extending through the soft tissues in direction to the right eye. Two outbreaks occurred in the State of Goiás 16-20 days after antihelmintic treatment in 5-9 months old lambs. Morbidity was 11.43% and 15.62% and fatality rate was 7.14% and 9.38%. Main clinical signs were nervous signs caused by abscesses with a diameter of 0.5-3cm, containing purulent exudates in the oropharynx, soft palate and adjacent muscles extending to the meninges through the atlantoaxial joint. Not-purulent meningitis was observed histologically. The need to use proper drenching guns and pay attention during dosing to avoid lesions of the oropharynx is pointed out.

Abstract in English:

ABSTRACT.- Almeida M.B., Tortelli F.P., Riet-Correa B., Ferreira J.L.M., Soares M.P., Farias N.A.R., Riet-Correa F. & Schild A.L. 2006. [Tick fever in southern Brazil: a retrospective study of 1978-2005.] Tristeza parasitária bovina na região sul do Rio Grande do Sul: estudo retrospectivo de 1978-2005. Pesquisa Veterinária Brasileira 26(4):236-242. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br A retrospective study of tick fever was made, which occurred from 1978-2005 in southern Rio Grande do Sul in the influence area of the Regional Diagnostic Laboratory of the Federal University of Pelotas. From 4,884 cattle specimens, sent by practitioners or which were from necropsies performed at the Diagnostic Laboratory, 231 (4.7%) were diagnosed as tick fever. Data from 221 of those outbreaks were analyzed. Ninety one (41.1%) outbreaks were caused by Babesia bovis, 11 (4.9%) by Babesia bigemina, and 65 (29.41%) by Anaplasma marginale. In other 33 (14.93%) outbreaks of babesiosis there is no information if the disease was caused by B. bovis or B. bigemina, and 21 (9.5%) outbreaks were caused by mixed infection of A. marginale and B. bovis or B. bigemina. Mean morbidity, mortality, and letality rates in 149 outbreaks were 11.17%, 6.81%, and 70.04%, respectively. Most outbreaks occurred during summer (January-March) and autumn (April-June), mainly in 1 to 3-year-old cattle. Clinical signs were depression, weakness, fallen ears, fever, and weight loss. Low packed cell volume values were always found. Hemoglobinury was observed in babesiosis. Neurological signs characterized by gait alterations, muscular tremors, aggressiveness and falling down with tonic and clonic convulsions were observed in babesiosis by B. bovis. The main gross lesions were anemia, jaundice, splenomegaly, hepatomegaly, yellow liver and cardiac hemorrhages. Hemoglobinury was observed in babesiosis, and congestion of the cerebral cortex in babesiosis by B. bovis. It is concluded that B. bovis is the main agent causing thick fever in southern Rio Grande do Sul. In that region with a cattle population of 2,630,000 heads the annual losses due to tick fever can be estimated in 6,220 cattle or US$ 1,623,000.00. Preventive measures to diminish tick fever losses in the region are necessary.

• Parasitic diseases tick fever epidemiology Babesia bovis Babesia bigemina Anaplasma marginale

Abstract in Portuguese:

ABSTRACT.- Almeida M.B., Tortelli F.P., Riet-Correa B., Ferreira J.L.M., Soares M.P., Farias N.A.R., Riet-Correa F. & Schild A.L. 2006. [Tick fever in southern Brazil: a retrospective study of 1978-2005.] Tristeza parasitária bovina na região sul do Rio Grande do Sul: estudo retrospectivo de 1978-2005. Pesquisa Veterinária Brasileira 26(4):236-242. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br A retrospective study of tick fever was made, which occurred from 1978-2005 in southern Rio Grande do Sul in the influence area of the Regional Diagnostic Laboratory of the Federal University of Pelotas. From 4,884 cattle specimens, sent by practitioners or which were from necropsies performed at the Diagnostic Laboratory, 231 (4.7%) were diagnosed as tick fever. Data from 221 of those outbreaks were analyzed. Ninety one (41.1%) outbreaks were caused by Babesia bovis, 11 (4.9%) by Babesia bigemina, and 65 (29.41%) by Anaplasma marginale. In other 33 (14.93%) outbreaks of babesiosis there is no information if the disease was caused by B. bovis or B. bigemina, and 21 (9.5%) outbreaks were caused by mixed infection of A. marginale and B. bovis or B. bigemina. Mean morbidity, mortality, and letality rates in 149 outbreaks were 11.17%, 6.81%, and 70.04%, respectively. Most outbreaks occurred during summer (January-March) and autumn (April-June), mainly in 1 to 3-year-old cattle. Clinical signs were depression, weakness, fallen ears, fever, and weight loss. Low packed cell volume values were always found. Hemoglobinury was observed in babesiosis. Neurological signs characterized by gait alterations, muscular tremors, aggressiveness and falling down with tonic and clonic convulsions were observed in babesiosis by B. bovis. The main gross lesions were anemia, jaundice, splenomegaly, hepatomegaly, yellow liver and cardiac hemorrhages. Hemoglobinury was observed in babesiosis, and congestion of the cerebral cortex in babesiosis by B. bovis. It is concluded that B. bovis is the main agent causing thick fever in southern Rio Grande do Sul. In that region with a cattle population of 2,630,000 heads the annual losses due to tick fever can be estimated in 6,220 cattle or US$ 1,623,000.00. Preventive measures to diminish tick fever losses in the region are necessary.

Abstract in English:

ABSTRACT.- Schild A.L., Sallis E.S.V., Priebe A.P., Soares M.P., Almeida M.B., Ladeira S.R.L., Schramm R. & Riet-Correa F. 2006. Anthrax in cattle in southern Brazil: 1978-2006. Pesquisa Veterinária Brasileira 26(4):243-248. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Univer-sidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br Ten outbreaks of anthrax occurred in cattle from 1978 to 2006 in southern Brazil, in 5 municipalities on the border with Uruguay, a country where the disease is frequent. The 10 outbreaks represented 0.2% of all bovine specimens received during the period by the Regional Diagnostic Laboratory of the Federal University of Pelotas, causing 267 deaths in a risk population of 6,605 head. The disease affected young and adult cattle mainly during summer. Only one farmer reported that sheep and horses were also affected. Clinically the peracute form was more frequent, but in some outbreaks the acute form with a clinical manifestation period of 6-48 hours was also observed. The source of infection was not established; but the reduced rainfall, associated with low, flat, flooded lands used for agriculture followed by animal grazing after harvest was probably related to the disease occurrence. Annual vaccination is an efficient way to prevent the disease.

• Anthrax Bacillus anthracis infectious disease disease of cattle

Abstract in Portuguese:

ABSTRACT.- Schild A.L., Sallis E.S.V., Priebe A.P., Soares M.P., Almeida M.B., Ladeira S.R.L., Schramm R. & Riet-Correa F. 2006. Anthrax in cattle in southern Brazil: 1978-2006. Pesquisa Veterinária Brasileira 26(4):243-248. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Univer-sidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br Ten outbreaks of anthrax occurred in cattle from 1978 to 2006 in southern Brazil, in 5 municipalities on the border with Uruguay, a country where the disease is frequent. The 10 outbreaks represented 0.2% of all bovine specimens received during the period by the Regional Diagnostic Laboratory of the Federal University of Pelotas, causing 267 deaths in a risk population of 6,605 head. The disease affected young and adult cattle mainly during summer. Only one farmer reported that sheep and horses were also affected. Clinically the peracute form was more frequent, but in some outbreaks the acute form with a clinical manifestation period of 6-48 hours was also observed. The source of infection was not established; but the reduced rainfall, associated with low, flat, flooded lands used for agriculture followed by animal grazing after harvest was probably related to the disease occurrence. Annual vaccination is an efficient way to prevent the disease.

Abstract in English:

ABSTRACT.- Guedes K.M.R., Schild A.L. Riet-Correa F., Barros S.S. & Simões S.V.D. 2006. [Spongious degeneration in the central nervous system in Sindhi calves]. Degeneração esponjosa no sistema nervoso central de bezerros da raça Sindhi. Pesquisa Veterinária Brasileira 26(3):157-160. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, Paraíba, Brazil. E-mail franklin.riet@pesquisador.cnpq.br Spongy degeneration (status spongiosus) includes many histological alterations characterized by vacuoles in the neuropile in different regions of the central nervous system (CNS). The vacuolization can be caused by intramyelinic edema, as in maple syrup urine disease and some toxic diseases, or by astrocytic edema, as in citrullinemia. This paper reports a spongy degeneration in two Sindhi calves, a female and a male. Both calves were offspring from the same bull, and the herd had high degree of inbreeding. The female calf was born normal, but progressive nervous signs were observed since 2 months old. The male calf had progressive nervous signs since it was born. Both calves were euthanized with severe nervous signs when 4 months old. At necropsy the liver was pale in the male calf. Histological alterations were mild to accentuated vacuolization, mainly in the deep cerebral cortex, cerebellar white matter, grey matter of the spinal cord, internal capsule, and brain stem. Fatty degeneration was observed in the liver of both animals. On electron microscopy it was found that the status spongiosus was caused by astrocytic edema. It is suggested that the disease is caused by a metabolic hereditary error.

• Status spongiosus astrocytic edema congenital diseases cattle

Abstract in Portuguese:

ABSTRACT.- Guedes K.M.R., Schild A.L. Riet-Correa F., Barros S.S. & Simões S.V.D. 2006. [Spongious degeneration in the central nervous system in Sindhi calves]. Degeneração esponjosa no sistema nervoso central de bezerros da raça Sindhi. Pesquisa Veterinária Brasileira 26(3):157-160. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, Paraíba, Brazil. E-mail franklin.riet@pesquisador.cnpq.br Spongy degeneration (status spongiosus) includes many histological alterations characterized by vacuoles in the neuropile in different regions of the central nervous system (CNS). The vacuolization can be caused by intramyelinic edema, as in maple syrup urine disease and some toxic diseases, or by astrocytic edema, as in citrullinemia. This paper reports a spongy degeneration in two Sindhi calves, a female and a male. Both calves were offspring from the same bull, and the herd had high degree of inbreeding. The female calf was born normal, but progressive nervous signs were observed since 2 months old. The male calf had progressive nervous signs since it was born. Both calves were euthanized with severe nervous signs when 4 months old. At necropsy the liver was pale in the male calf. Histological alterations were mild to accentuated vacuolization, mainly in the deep cerebral cortex, cerebellar white matter, grey matter of the spinal cord, internal capsule, and brain stem. Fatty degeneration was observed in the liver of both animals. On electron microscopy it was found that the status spongiosus was caused by astrocytic edema. It is suggested that the disease is caused by a metabolic hereditary error.

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:

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:

Rech R.R., Schild A.L., Driemeier D., Garmatz S.L., Oliveira F.N., Riet-Correa F. & Barros C.S.L. 2005. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Epidemiology, clinical signs and pathology.] Febre catarral maligna em bovinos no Rio Grande do Sul: epidemiologia, sinais clínicos e patologia. Pesquisa Veterinária Brasileira 25(2):97-105. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical signs, necropsy and histopathological findings in cases of malignant catarrhal fever (MCF) occurring in cattle from 15 farms in Rio Grande do Sul, Brazil, from 1973 to 2003, are described. In 9 instances (60%) the disease occurred as sporadic cases affecting 1-3 cattle whereas in six farms (40%) MCF occurred as epizootics involving several cattle in each affected herd. Morbidity rates ranged from 2.4% to 20% and lethality rates were 83.3% and 100%. Cattle of all ages and both sexes were affected. Where the information was available (9 farms) sheep were in contact with affected cattle and cases of MCF occurred more frequently in spring and summer. Clinical courses were acute or subacute and clinical signs included fever, nasal and ocular discharges, conjunctivitis, drooling, hematuria, necrosis and blunting of buccal papillae, enlargement of lymph nodes, diarrhea and neurological disturbances. Necropsy findings included opaque corneas, reddening, erosions and ulcerations in several mucous membranes of the alimentary, respiratory and urogenital tracts, and the conjunctiva; enlargement and haemorrhage of lymph nodes and multiple white foci in the renal cortices and in the hepatic portal triads. Crustous dermatitis was observed in some cases. Main histopathological findings included vasculitis, necrosis of the surface epithelia and accumulation of inflammatory cells in several organs. Vasculitis were associated with fibrinoid necrosis of the medial layer of arteries and inflammatory cells included lymphoblasts, lymphocytes, plasma cells and macrophages.

• Infectious diseases epidemiology viral diseases diseases of cattle pathology.

Abstract in Portuguese:

Rech R.R., Schild A.L., Driemeier D., Garmatz S.L., Oliveira F.N., Riet-Correa F. & Barros C.S.L. 2005. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Epidemiology, clinical signs and pathology.] Febre catarral maligna em bovinos no Rio Grande do Sul: epidemiologia, sinais clínicos e patologia. Pesquisa Veterinária Brasileira 25(2):97-105. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical signs, necropsy and histopathological findings in cases of malignant catarrhal fever (MCF) occurring in cattle from 15 farms in Rio Grande do Sul, Brazil, from 1973 to 2003, are described. In 9 instances (60%) the disease occurred as sporadic cases affecting 1-3 cattle whereas in six farms (40%) MCF occurred as epizootics involving several cattle in each affected herd. Morbidity rates ranged from 2.4% to 20% and lethality rates were 83.3% and 100%. Cattle of all ages and both sexes were affected. Where the information was available (9 farms) sheep were in contact with affected cattle and cases of MCF occurred more frequently in spring and summer. Clinical courses were acute or subacute and clinical signs included fever, nasal and ocular discharges, conjunctivitis, drooling, hematuria, necrosis and blunting of buccal papillae, enlargement of lymph nodes, diarrhea and neurological disturbances. Necropsy findings included opaque corneas, reddening, erosions and ulcerations in several mucous membranes of the alimentary, respiratory and urogenital tracts, and the conjunctiva; enlargement and haemorrhage of lymph nodes and multiple white foci in the renal cortices and in the hepatic portal triads. Crustous dermatitis was observed in some cases. Main histopathological findings included vasculitis, necrosis of the surface epithelia and accumulation of inflammatory cells in several organs. Vasculitis were associated with fibrinoid necrosis of the medial layer of arteries and inflammatory cells included lymphoblasts, lymphocytes, plasma cells and macrophages.