PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Rech R.R., Rissi D.R., Silva M.C., Inkelmann M.A. & Barros C.S.L. 2006. [Histomorphology of the Gasserian ganglion, carotid rete mirabile and pituitary gland in cattle: a study of 199 cases.] Histomorfologia do gânglio de Gasser, da rete mirabile carotídea e da hipófise de bovinos: estudo de 199 casos. Pesquisa Veterinária Brasileira 26(2):105-111. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The complex of heterogenous tissues formed by the Gasserian ganglia, carotid rete mirabile and pituitary gland (GRH) from 199 cattle were grossly and histologically evaluated. Twenty one of the GRH were from comfirmed cases of rabies, 19 were diagnosed as cases of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5), 11 were confirmed cases of malignant catarrhal fever (MCF), 7 had pituitary abscesses, 17 had lesions of hepatic encephalopathy (status spongiosus) attributable to chronic liver failure due to Senecio sp poisoning; and the remaining 124 GRH were from cattle which did not present neurological signs and died or were euthanatized due to various causes. No significant histologic changes were observed in the GRH from the 124 cattle which did not present neurological signs, in the GRH of the 17 cattle that had hepatic encephalopathy neither in the GRH of the 19 cattle diagnosed with BoHV-5 meningoencephalitis. Inflammatory changes were found in the Gasserian ganglia of 20 out of 21 cases of rabies and consisted of proliferation of sattelite cells, glial nodules and lymphoplasmacytic infiltrate; degenerative changes included central chromatolysis, neuronal vacuolation, and neuronal death with neuronophagia. Characteristic eosinophilic intracytoplasmatic inclusion (Negri) bodies were found in 19 out of 21 cases of rabies, neuritis of the fifth nerve in 11, and neurohypophysitis in 4 cases. The GRH from nine of the eleven cases of MCF had characteristic necrotizing arteritis affecting the arteries of the carotid rete mirabile. In seven cases pituitary abscesses were found; they were characterized by large aggregates of neutrophils admixed with cellular debris and surrounded by mononuclear cells and were walled by a fibrous capsule. Several incidental findings were observed equally in the 199 histologically examined GRH and consequently were non specific for any disease entity. These include cysts in the pituitary cleft, fibrin and neutrophilic aggregates in the cavernous sinus of the carotid rete mirabile, mildly increased numbers of sattelite cells around neurons of the Gasserian ganglia and occasional neuronal vacuolation and lipofuscinosis. It was concluded that the histological examination of the GRH is an important and reliable tool in the diagnosis of the main forms of encephalitis occurring in cattle in Brazil.

• Diseases of cattle diseases of the central nervous system Gasserian ganglion carotid rete mirabile pituitary gland neuropathology.

Abstract in Portuguese:

ABSTRACT.- Rech R.R., Rissi D.R., Silva M.C., Inkelmann M.A. & Barros C.S.L. 2006. [Histomorphology of the Gasserian ganglion, carotid rete mirabile and pituitary gland in cattle: a study of 199 cases.] Histomorfologia do gânglio de Gasser, da rete mirabile carotídea e da hipófise de bovinos: estudo de 199 casos. Pesquisa Veterinária Brasileira 26(2):105-111. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The complex of heterogenous tissues formed by the Gasserian ganglia, carotid rete mirabile and pituitary gland (GRH) from 199 cattle were grossly and histologically evaluated. Twenty one of the GRH were from comfirmed cases of rabies, 19 were diagnosed as cases of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5), 11 were confirmed cases of malignant catarrhal fever (MCF), 7 had pituitary abscesses, 17 had lesions of hepatic encephalopathy (status spongiosus) attributable to chronic liver failure due to Senecio sp poisoning; and the remaining 124 GRH were from cattle which did not present neurological signs and died or were euthanatized due to various causes. No significant histologic changes were observed in the GRH from the 124 cattle which did not present neurological signs, in the GRH of the 17 cattle that had hepatic encephalopathy neither in the GRH of the 19 cattle diagnosed with BoHV-5 meningoencephalitis. Inflammatory changes were found in the Gasserian ganglia of 20 out of 21 cases of rabies and consisted of proliferation of sattelite cells, glial nodules and lymphoplasmacytic infiltrate; degenerative changes included central chromatolysis, neuronal vacuolation, and neuronal death with neuronophagia. Characteristic eosinophilic intracytoplasmatic inclusion (Negri) bodies were found in 19 out of 21 cases of rabies, neuritis of the fifth nerve in 11, and neurohypophysitis in 4 cases. The GRH from nine of the eleven cases of MCF had characteristic necrotizing arteritis affecting the arteries of the carotid rete mirabile. In seven cases pituitary abscesses were found; they were characterized by large aggregates of neutrophils admixed with cellular debris and surrounded by mononuclear cells and were walled by a fibrous capsule. Several incidental findings were observed equally in the 199 histologically examined GRH and consequently were non specific for any disease entity. These include cysts in the pituitary cleft, fibrin and neutrophilic aggregates in the cavernous sinus of the carotid rete mirabile, mildly increased numbers of sattelite cells around neurons of the Gasserian ganglia and occasional neuronal vacuolation and lipofuscinosis. It was concluded that the histological examination of the GRH is an important and reliable tool in the diagnosis of the main forms of encephalitis occurring in cattle in Brazil.

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:

Langohr I.M., Gava A. & Barros C.S.L. 2005. [Poisoning in cattle by Baccharidastrum triplinervium (Asteraceae).] Intoxicação por Baccharidastrum triplinervium (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 25(4):235-238. Animal Disease Diagnostic Laboratory, Purdue University, 406 South University, West Lafayette, IN 47907, Estados Unidos. E-mail: ilangohr@purdue.edu An outbreak of poisoning by Baccharidastrum triplinervium in cattle from Paraná, Brazil, is described. The disease occurred during a severe drought in early summer. The onset of clinical signs was two days after 50 cows and 8 heifers had been introduced into a pasture with high density of B. triplinervium that showed signs of having been consumed by the animals. Fifteen animals (9 cows and 6 heifers) got sick. Of these 15, two cows and four heifers died after a clinical course of 12-60 hours. Clinical signs included depression, ruminal atony, moderate bloat, marked dehydration, mild diarrhea and anorexia. The animals were restless, laying down and getting up constantly, remaining progressively longer periods in sternal recumbency. Once in that position, the animals had an extended head or the head turned to one of the sides of the body, and were groaning. Additionally, the cows had an abrupt fall in milk yield. The remaining affected cattle presented milder clinical signs and were partially back to their feed on the day following the onset of the clinical signs. The milk production was back to normal values within one week. The main gross lesions observed in two necropsied cows were in the forestomachs and abomasum, consisting of edema of the ruminal wall, as well as of diffuse reddening of the mucosae of the rumen, reticulum, abomasum and of some of the omasal folds. The main histological lesions included multifocal ballooning degeneration and necrosis of the lining epithelium of the rumen, associated with neutrophilic infiltrate. The diagnosis was based on the epidemiological data and on the experimental reproduction of the disease by force-feeding 3 bovine with the aeral fresh parts (20 and 30g/kg) of B. triplinervium. Chemical analysis of dried material from B. triplinervium harvested at the site of the outbreak was negative for macrocyclic trichothecenes.

• Poisonous plants Baccharidastrum triplinervium Asteraceae plant poisoning diseases of cattle pathology.

Abstract in Portuguese:

Langohr I.M., Gava A. & Barros C.S.L. 2005. [Poisoning in cattle by Baccharidastrum triplinervium (Asteraceae).] Intoxicação por Baccharidastrum triplinervium (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 25(4):235-238. Animal Disease Diagnostic Laboratory, Purdue University, 406 South University, West Lafayette, IN 47907, Estados Unidos. E-mail: ilangohr@purdue.edu An outbreak of poisoning by Baccharidastrum triplinervium in cattle from Paraná, Brazil, is described. The disease occurred during a severe drought in early summer. The onset of clinical signs was two days after 50 cows and 8 heifers had been introduced into a pasture with high density of B. triplinervium that showed signs of having been consumed by the animals. Fifteen animals (9 cows and 6 heifers) got sick. Of these 15, two cows and four heifers died after a clinical course of 12-60 hours. Clinical signs included depression, ruminal atony, moderate bloat, marked dehydration, mild diarrhea and anorexia. The animals were restless, laying down and getting up constantly, remaining progressively longer periods in sternal recumbency. Once in that position, the animals had an extended head or the head turned to one of the sides of the body, and were groaning. Additionally, the cows had an abrupt fall in milk yield. The remaining affected cattle presented milder clinical signs and were partially back to their feed on the day following the onset of the clinical signs. The milk production was back to normal values within one week. The main gross lesions observed in two necropsied cows were in the forestomachs and abomasum, consisting of edema of the ruminal wall, as well as of diffuse reddening of the mucosae of the rumen, reticulum, abomasum and of some of the omasal folds. The main histological lesions included multifocal ballooning degeneration and necrosis of the lining epithelium of the rumen, associated with neutrophilic infiltrate. The diagnosis was based on the epidemiological data and on the experimental reproduction of the disease by force-feeding 3 bovine with the aeral fresh parts (20 and 30g/kg) of B. triplinervium. Chemical analysis of dried material from B. triplinervium harvested at the site of the outbreak was negative for macrocyclic trichothecenes.

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.

Abstract in English:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

• Poisonous plants Baccharis coridifolia Asteraceae diseases of cattle pathology.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

Abstract in English:

Rech R.R, Fighera R.A., Oliveira F.N. & Barros C.S.L. 2004. [Granulomatous meningoencephalitis in cattle grazing vetch (Vicia spp).] Meningoencefalite granulomatosa em bovinos em pastoreio de ervilhaca (Vicia spp). Pesquisa Veterinária Brasileira 24(3): 169-172. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Granulomatous meningoencephalitis was observed in 7 out of 8 adult dairy cows affected by vetch-associated systemic granulomatous disease, although there was no neurological signs associated with the condition. The cellular inflammatory infiltrates were located in the leptomeninges and as perivascular cuffings within the brain and consisted of epithelioid macrophages, lymphocytes, plasm cells and eosinophils. These inflammatory changes varied from mild to severe from animal to animal and among different brain regions of the same animal. Perivascular cuffings were usually more marked than the leptomeningeal infiltrates. Affected brain regions, in decreasing order of intensity, included diencephalon through the level of massa intermedia, mesencephalon at the level of rostral colliculi, pons and cerebellar peduncles, medulla at the level of obex, frontal lobe at the level of the genu of the corpus callosum, and cerebellum. The character and the distribution of the inflammatory changes are emphasized regarding the differential diagnosis with other diseases and lesions of the bovine central nervous system in the context of the Brazilian surveillance program for bovine spongiform encephalopath.

• Diseases of cattle diseases of the central nervous system meningoencephalitis plant poisoning Vicia spp pathology.

Abstract in Portuguese:

Rech R.R, Fighera R.A., Oliveira F.N. & Barros C.S.L. 2004. [Granulomatous meningoencephalitis in cattle grazing vetch (Vicia spp).] Meningoencefalite granulomatosa em bovinos em pastoreio de ervilhaca (Vicia spp). Pesquisa Veterinária Brasileira 24(3): 169-172. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Granulomatous meningoencephalitis was observed in 7 out of 8 adult dairy cows affected by vetch-associated systemic granulomatous disease, although there was no neurological signs associated with the condition. The cellular inflammatory infiltrates were located in the leptomeninges and as perivascular cuffings within the brain and consisted of epithelioid macrophages, lymphocytes, plasm cells and eosinophils. These inflammatory changes varied from mild to severe from animal to animal and among different brain regions of the same animal. Perivascular cuffings were usually more marked than the leptomeningeal infiltrates. Affected brain regions, in decreasing order of intensity, included diencephalon through the level of massa intermedia, mesencephalon at the level of rostral colliculi, pons and cerebellar peduncles, medulla at the level of obex, frontal lobe at the level of the genu of the corpus callosum, and cerebellum. The character and the distribution of the inflammatory changes are emphasized regarding the differential diagnosis with other diseases and lesions of the bovine central nervous system in the context of the Brazilian surveillance program for bovine spongiform encephalopath.

Abstract in English:

Garmatz S.L., Irigoyen L.F., Rech R.R., Brown C.C., Zhang J. & Barros C.S.L. 2004. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Experimental transmission to cattle and characterization of the etiological agent.] Febre catarral maligna em bovinos no Rio Grande do Sul: transmissão experimental para bovinos e caracterização do agente etiológico. Pesquisa Veterinária Brasileira 24(2):93-106. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of malignant catarrhal fever (MCF) occurring in cattle on two farms (A and B) in the municipality of Santiago, state of Rio Grande do Sul (RS), Brazil, and the transmission of the disease to susceptible calves as well as the detection of ovine herpesvirus-2 (OvHV-2) in tissues of affected cattle are reported. The two epizootics occurred from November 2001 to February 2002 (Farm A) and in January-February 2003 (Farm B). Numbers of cattle at risk, morbidity and letality rates were respectively 170, 10.59% and 83.33% for Farm A and 500, 2.4% and 100% for Farm B. Contact between affected cattle and sheep was detected in both farms, but lambing ewes were present only in farm A. Duration of clinical courses, gross findings and histopathology were the same for the affected cattle in both farms. Most affected cattle died or were euthanatized in extremis after a clinical course of 2-8 days. Clinical signs included fever (40.5 and 41.5°C), nasal and ocular discharge, corneal opacity, conjunctivitis, drooling, erosions and ulcerations of the mucosae, diarrhea, hematuria, and neurological disturbances. Eleven necropsies (9 on Farm A, 2 on Farm B) were performed. Gross lesions included erosions and ulcers affecting the mucosae of nasal turbinates, oral cavity, gastrointestinal and urogenital tracts; hemorrhage and necrosis of the tip of the buccal papillae, lymph node enlargement, multifocal white foci in renal cortex, and hyperemia of leptomeninges. Microscopically, there were arteritis and fibrinoid degeneration in medium and small arteries and arterioles of multiple organs and tissues, necrosis and inflammation in several mucosal surfaces, keratitis, conjunctivitis, uveitis, intersticial nephritis, and encephalitis. Transmission experiments were attempted in five calves (E1-E5) by inocculating each of them intravenously with 500 ml of whole heparinized blood from a MCF affected cow. The transmission was suscessful in at least three (E1-E3) of the experimental calves which became sick after an incubation period of 15-27 days. Four experimental calves either died or were euthanatized in extremis after a clinical course which varied from 3 days to 8 weeks. The remaining experimental calf (E5) recovered from a mild disease and was euthanatized 14 weeks after inocculation. Necropsies were performed in all five calves. Clinical signs, necropsy and histopathological findings of three calves (E1-E3) were characteristic of MCF. OvHV-2 viral DNA was detected by the polimerase chain reaction (PCR) test in paraffin embedded tissues from seven cattle out of the 11 spontaneous MCF cases and from three experimental calves (E1-E3). PCR tests resulted negative in the remaining four of the 11 spontaneous MCF cases tested and in two (E4,E5) of the five experimental calves. Immunohistochemistry performed in sections of lymphoid tissue from calf E4 failed to detect BVD virus antigen. The experimental transmission of MCF and the characterization of the etiological agent as OvHV-2 were successfully attempted in cattle for the first time in Brazil.

• Infectious diseases malignant catarrhal fever viral diseases diseases of cattle pathology polimerase chain reation.

Abstract in Portuguese:

Garmatz S.L., Irigoyen L.F., Rech R.R., Brown C.C., Zhang J. & Barros C.S.L. 2004. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Experimental transmission to cattle and characterization of the etiological agent.] Febre catarral maligna em bovinos no Rio Grande do Sul: transmissão experimental para bovinos e caracterização do agente etiológico. Pesquisa Veterinária Brasileira 24(2):93-106. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of malignant catarrhal fever (MCF) occurring in cattle on two farms (A and B) in the municipality of Santiago, state of Rio Grande do Sul (RS), Brazil, and the transmission of the disease to susceptible calves as well as the detection of ovine herpesvirus-2 (OvHV-2) in tissues of affected cattle are reported. The two epizootics occurred from November 2001 to February 2002 (Farm A) and in January-February 2003 (Farm B). Numbers of cattle at risk, morbidity and letality rates were respectively 170, 10.59% and 83.33% for Farm A and 500, 2.4% and 100% for Farm B. Contact between affected cattle and sheep was detected in both farms, but lambing ewes were present only in farm A. Duration of clinical courses, gross findings and histopathology were the same for the affected cattle in both farms. Most affected cattle died or were euthanatized in extremis after a clinical course of 2-8 days. Clinical signs included fever (40.5 and 41.5°C), nasal and ocular discharge, corneal opacity, conjunctivitis, drooling, erosions and ulcerations of the mucosae, diarrhea, hematuria, and neurological disturbances. Eleven necropsies (9 on Farm A, 2 on Farm B) were performed. Gross lesions included erosions and ulcers affecting the mucosae of nasal turbinates, oral cavity, gastrointestinal and urogenital tracts; hemorrhage and necrosis of the tip of the buccal papillae, lymph node enlargement, multifocal white foci in renal cortex, and hyperemia of leptomeninges. Microscopically, there were arteritis and fibrinoid degeneration in medium and small arteries and arterioles of multiple organs and tissues, necrosis and inflammation in several mucosal surfaces, keratitis, conjunctivitis, uveitis, intersticial nephritis, and encephalitis. Transmission experiments were attempted in five calves (E1-E5) by inocculating each of them intravenously with 500 ml of whole heparinized blood from a MCF affected cow. The transmission was suscessful in at least three (E1-E3) of the experimental calves which became sick after an incubation period of 15-27 days. Four experimental calves either died or were euthanatized in extremis after a clinical course which varied from 3 days to 8 weeks. The remaining experimental calf (E5) recovered from a mild disease and was euthanatized 14 weeks after inocculation. Necropsies were performed in all five calves. Clinical signs, necropsy and histopathological findings of three calves (E1-E3) were characteristic of MCF. OvHV-2 viral DNA was detected by the polimerase chain reaction (PCR) test in paraffin embedded tissues from seven cattle out of the 11 spontaneous MCF cases and from three experimental calves (E1-E3). PCR tests resulted negative in the remaining four of the 11 spontaneous MCF cases tested and in two (E4,E5) of the five experimental calves. Immunohistochemistry performed in sections of lymphoid tissue from calf E4 failed to detect BVD virus antigen. The experimental transmission of MCF and the characterization of the etiological agent as OvHV-2 were successfully attempted in cattle for the first time in Brazil.

Abstract in English:

Cattani C.S.O., Colodel E.M., Traverso S.D., Correa A.M.R., & Driemeier D. 2004. [Experimental poisoning by Dodonea viscosa (Sapindaceae) in cattle.] Intoxicação experimental por Dodonea viscosa (Sapindaceae) em bovinos. Pesquisa Veterinária Brasileira 24(1):31-34. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br The leaves of Dodonea viscosa were force fed to five bovines. Four received the leaves in fresh green stage and the fifth dried ones. Clinical signs were observed in four of the bovines that died; the fifth did not show signs of poisoning. The fresh green plant was proved to be toxic from a dose of 25g/kg on. Dried leaves fed at the dose of 30 g/kg were also toxic. All the animals that died showed clinical signs from 13h30min to 45h after the ingestion of the plant and and death followed within about 48h. The clinical course lasted for about 8h30min until death. The main symptoms where apathy, anorexia, slight tenesmus, muscle trembling, difficulties to keep consciousness, pressing the head against obstacles, lateral recumbency, paddling movements, coma and death. The most significant macroscopic alterations were observed in the liver, with accentuation of the lobular pattern, dark-red areas interspersed with yellowish areas. Petechiae were found in serosal membranes of the abdominal and thoracic organs as well as the intestines. The main microscopic change was hepatic centrolobular coagulative necrosis, associated with congestion and hemorrhages.

• Dodonea viscosa diseases of cattle plant poisoning hepatocellular necrosis.

Abstract in Portuguese:

Cattani C.S.O., Colodel E.M., Traverso S.D., Correa A.M.R., & Driemeier D. 2004. [Experimental poisoning by Dodonea viscosa (Sapindaceae) in cattle.] Intoxicação experimental por Dodonea viscosa (Sapindaceae) em bovinos. Pesquisa Veterinária Brasileira 24(1):31-34. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br The leaves of Dodonea viscosa were force fed to five bovines. Four received the leaves in fresh green stage and the fifth dried ones. Clinical signs were observed in four of the bovines that died; the fifth did not show signs of poisoning. The fresh green plant was proved to be toxic from a dose of 25g/kg on. Dried leaves fed at the dose of 30 g/kg were also toxic. All the animals that died showed clinical signs from 13h30min to 45h after the ingestion of the plant and and death followed within about 48h. The clinical course lasted for about 8h30min until death. The main symptoms where apathy, anorexia, slight tenesmus, muscle trembling, difficulties to keep consciousness, pressing the head against obstacles, lateral recumbency, paddling movements, coma and death. The most significant macroscopic alterations were observed in the liver, with accentuation of the lobular pattern, dark-red areas interspersed with yellowish areas. Petechiae were found in serosal membranes of the abdominal and thoracic organs as well as the intestines. The main microscopic change was hepatic centrolobular coagulative necrosis, associated with congestion and hemorrhages.

Abstract in English:

ABSTRACT.- Fighera R.A., Rozza D.B., Piazer J.V., Copetti M.V., lrigoyen L.F. & Barros C.S.L. 2003. [Interstitial pneumonia in cattle fed moldy sweet potatoes (Ipomoea batatas).] Pneumonia intersticial em bovinos associada à ingestão de batata-doce (lpomoea batatas) mofada. Pesquisa Veterinária Brasileira 23(4):161-166. Depto Patologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brasil. E-mail: claudioslbarros@uol.com.br Cases of respiratory disease were diagnosed in five out of 23 cattle (21. 7%) after they wete fed moldy damaged sweet potatoes (lpomoea batatas) on a small farm in the county of São Vicente do Sul, state of Rio Grande do Sul, Brazil. Of those five cattle, three died spontaneously and another one was euthanatized for necropsy while showing advanced respiratory clinicai signs. The disease manifested itself approximately 24 hours after the ingestion of the sweet potatoes and lasted from 1 to 4 days. Clinicai signs included dyspnea (labored breathing and abdominal respiration), tachypnea, extended neck with Iow carriage of the head and rhythmical flaring of the nostrils. Two cows were necropsied. Necropsy findings included distended pale and rubbery lungs which failed to collapse when the thorax was open, and marked pulmonar interstitial emphysema and edema. Lymphoid hyperplasia was observed in the hilar nodes and spleen. Histologically, the lesions were those of interstitial pneumonia. Alveolar septa were thickened by fibroblasts and inflammatory cells, and there was hypertrophy and hyperplasia of type li pneumocytes; the interlobular septa were distended by edema and emphysema. The culture of the moldy sweet potatoes yielded Fusarium solani and Fusarium oxysporum.

• Toxic diseases mycotoxicoses respiratory diseases interstitial pneumonia diseases of cattle sweet potatoes lpomoea batatas Intoxicações micotoxicoses doenças respiratórias pneumonia intersticial doenças de bovinos batata-doce.

Abstract in Portuguese:

RESUMO.- Fighera R.A., Rozza D.B., Piazer J.V., Copetti M.V., lrigoyen L.F. & Barros C.S.L. 2003. [Interstitial pneumonia in cattle fed moldy sweet potatoes (Ipomoea batatas).] Pneumonia intersticial em bovinos associada à ingestão de batata-doce (lpomoea batatas) mofada. Pesquisa Veterinária Brasileira 23(4):161-166. Depto Patologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brasil. E-mail: claudioslbarros@uol.com.br Uma doença respiratória foi diagnosticada em cinco dentre 23 bovinos (21, 7%) após terem sido alimentados com batata-doce (lpomoea batatas) mofada em uma pequena propriedade rural em São Vicente do Sul, Rio Grande do Sul, Brasil. Três dos cinco bovinos afetados morreram espontaneamente, e o quarto foi sacrificado para necropsia quando mostrava sinais clínicos respiratórios avançados. A manifestação clínica iniciara cerca de 24 horas após a ingestão das batatasdoces e a evolução clínica foi de 1 a 4 dias. Os sinais clínicos incluíam dispnéia (respiração laboriosa e abdominal), taquipnéia, pescoço estendido com cabeça baixa e dilatação ritmada das narinas. Dois bovinos foram necropsiados. Os achados de necropsia incluíam pulmões distendidos, pálidos e de consistência borrachenta, que não colapsavam quando o tórax era aberto; enfisema e edema acentuados eram evidentes no pulmão. Os linfonodos e o baço apresentavam alterações características de hiperplasia linfóide. Histologicamente, as lesões eram típicas de pneumonia intersticial. Os septos alveolares estavam espessados por fibroblastos e células inflamatórias, havia hipertrofia e hiperplasia de pneumócitos tipo II; os septos interlobulares estavam distendidos por edema e enfisema. A cultura de amostras das batatas-doces mofadas produziu Fusarium solani e F. oxysporum.