PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Souza N.R., Adorno V.B., Marcondes J.S., Oliveira Filho J.P., Conceição L.G., Amorim R.L. & Borges A.S. 2008. [Clinical and histopathological characteristics of the aural plaque in Mangalarga and Quarter Horses.] Características clínicas e histopatológicas da placa aural em eqüinos Mangalarga e Quarto de Milha. Pesquisa Veterinária Brasileira 28(6):279-284. Departamento de Clínica Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Unesp-Campus de Botucatu, Distrito de Rubião Júnior s/n, Botucatu, SP 18618000, Brazil. E-mail: zep.filho@hotmail.com Aural plaque is a variant of equine papillomatosis. Clinical examination was performed on 306 Mangalarga and 275 Quarter Horses to compare the occurrence of aural plaques among animals and to characterize clinical and histological findings for the disease. Aural plaques occurred in 57% of Mangalarga and in 35% of Quarter breeds. Clinically the lesions consisted of flat, desquamated and hypochromic plaques formed by coalescence of small papules. The main histopathological findings were epidermal hyperplasia and hypomelanosis with abrupt change between the normal and the affected epithelium.

• Equine papillomatosis aural plaques Mangalarga Quarter Horses

Abstract in Portuguese:

ABSTRACT.- Souza N.R., Adorno V.B., Marcondes J.S., Oliveira Filho J.P., Conceição L.G., Amorim R.L. & Borges A.S. 2008. [Clinical and histopathological characteristics of the aural plaque in Mangalarga and Quarter Horses.] Características clínicas e histopatológicas da placa aural em eqüinos Mangalarga e Quarto de Milha. Pesquisa Veterinária Brasileira 28(6):279-284. Departamento de Clínica Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Unesp-Campus de Botucatu, Distrito de Rubião Júnior s/n, Botucatu, SP 18618000, Brazil. E-mail: zep.filho@hotmail.com Aural plaque is a variant of equine papillomatosis. Clinical examination was performed on 306 Mangalarga and 275 Quarter Horses to compare the occurrence of aural plaques among animals and to characterize clinical and histological findings for the disease. Aural plaques occurred in 57% of Mangalarga and in 35% of Quarter breeds. Clinically the lesions consisted of flat, desquamated and hypochromic plaques formed by coalescence of small papules. The main histopathological findings were epidermal hyperplasia and hypomelanosis with abrupt change between the normal and the affected epithelium.

Abstract in English:

ABSTRACT.- Botteon P.T.L., Ferraz V.P., Glória M.B.A., Melo M.M., Paes Leme F.O., Faleiros R.R. & Alves G.E.S. 2008. [Plasmatic concentrations of tryptamine, tyramine end phenylethylamine in horses under the effect of carbohydrate overload and non-steroid antinflammatory compounds.] Concentrações plasmáticas de triptamina, tiramina e feniletilamina em eqüinos sob efeitos de sobrecarga de carboidratos e antiinflamatórios não esteroidais. Pesquisa Veterinária Brasileira 28(6):299-302. Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG, 30123-970, Brazil. E-mail: paulobotteon@gmail.com The concentrations of the bioactives amines tryptamine (TRP), tyramine (TYR) and phenylethylamine (PEA) were determined by gas chromatography in plasma samples of 20 horses submitted to carbohydrate overload. Thirty hours after the overload, the horses were randomly distributed in four groups (n=5) and were submitted to four IV treatments every 12 hours: 10ml of saline (GC), ketoprofen 2.2mg/kg (GK), phenylbutazone 4.4mg/kg (GF), and flunixin meglumine 1.1mg/kg (GFM). Blood samples were collected at various times after the overload (0-72 h). Plasma TYR and PEA concentrations ranged from 0.18 to 164.2mg/L, and differed significantly with time (p<0.01), but did not differ in the treatments. Plasma concentrations of TRP differed between times and treatments. The GC was significantly major than other treatments at 48h and 60h after the overload, and the plasma concentration of TRP in groups GK and GFM was significantly lower than in groups GF and GC at 72 h (p=0.0012). We concluded that the anti-inflammatory drugs evaluated do not interfere in the plasma concentration of TYP and PEA. For TRP, ketoprofen and flunixin meglumine was effective to reduce de plasmatic concentration of this amine.

• Amines antinflammatory compounds laminitis horse

Abstract in Portuguese:

ABSTRACT.- Botteon P.T.L., Ferraz V.P., Glória M.B.A., Melo M.M., Paes Leme F.O., Faleiros R.R. & Alves G.E.S. 2008. [Plasmatic concentrations of tryptamine, tyramine end phenylethylamine in horses under the effect of carbohydrate overload and non-steroid antinflammatory compounds.] Concentrações plasmáticas de triptamina, tiramina e feniletilamina em eqüinos sob efeitos de sobrecarga de carboidratos e antiinflamatórios não esteroidais. Pesquisa Veterinária Brasileira 28(6):299-302. Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG, 30123-970, Brazil. E-mail: paulobotteon@gmail.com The concentrations of the bioactives amines tryptamine (TRP), tyramine (TYR) and phenylethylamine (PEA) were determined by gas chromatography in plasma samples of 20 horses submitted to carbohydrate overload. Thirty hours after the overload, the horses were randomly distributed in four groups (n=5) and were submitted to four IV treatments every 12 hours: 10ml of saline (GC), ketoprofen 2.2mg/kg (GK), phenylbutazone 4.4mg/kg (GF), and flunixin meglumine 1.1mg/kg (GFM). Blood samples were collected at various times after the overload (0-72 h). Plasma TYR and PEA concentrations ranged from 0.18 to 164.2mg/L, and differed significantly with time (p<0.01), but did not differ in the treatments. Plasma concentrations of TRP differed between times and treatments. The GC was significantly major than other treatments at 48h and 60h after the overload, and the plasma concentration of TRP in groups GK and GFM was significantly lower than in groups GF and GC at 72 h (p=0.0012). We concluded that the anti-inflammatory drugs evaluated do not interfere in the plasma concentration of TYP and PEA. For TRP, ketoprofen and flunixin meglumine was effective to reduce de plasmatic concentration of this amine.

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.- Faleiros R.R., Macoris D.G., Alves G.E.S., Saquetti C.H.C. & Alessi A.C. 2007. [Histomorphometric and ultrastructural evaluation of the mucosa of the equine small colon subjected to distention.] Avaliação histomorfométrica e ultra-estrutural da mucosa do cólon menor eqüino submetido à distensão. Pesquisa Veterinária Brasileira 27(9):383-387. Departamento de Clínica e Cirurgia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Campus de Jaboticabal, Rodovia Carlos Tonanni Km 5, Jaboticabal, SP 14870-000, Brazil. E-mail: faleiros@ufmg.br Recently it has been shown that experimental distention of the small colon of horses promotes reduction of microvascular circulation and inflammation of the seromuscular layer associated with neutrophil accumulation in the lungs. However this model was not sufficient to induce evident histophatological changes in the mucosal layer. The aim of this study was to evaluate the mucosa subjected to that model of small colon distention by histomorphometry and scan electronic microscopy (SEM). Sixteen horses were used. In the distended group (DG), nine of them were subjected to distention of the small colon by a surgically implanted intraluminal balloon that was inflated with a pressure of 40mm Hg during 4 hours. In the sham-operated group (SG), the balloon was implanted but not inflated. Full-thickness intestinal samples were collected before and after obstruction and after 1.5 and 12 hours of decom-pression. By SEM, it was observed that the mucosa turned flat and smooth after distention and returned to the wrinkled original appearance after decompression. Twelve hours after decompression the mucosa had a more irregular appearance with points of fragmentation. There was a reduction in mucosa thickness after distention, returning to basal values after decompression. Instead of the fact that there were changes in appearance and thickness, it was concluded that the mucosa could borne up the compression caused by distention returning to the original characteristics without major lesions.

• Small colon intestinal distention colic horse

Abstract in Portuguese:

ABSTRACT.- Faleiros R.R., Macoris D.G., Alves G.E.S., Saquetti C.H.C. & Alessi A.C. 2007. [Histomorphometric and ultrastructural evaluation of the mucosa of the equine small colon subjected to distention.] Avaliação histomorfométrica e ultra-estrutural da mucosa do cólon menor eqüino submetido à distensão. Pesquisa Veterinária Brasileira 27(9):383-387. Departamento de Clínica e Cirurgia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Campus de Jaboticabal, Rodovia Carlos Tonanni Km 5, Jaboticabal, SP 14870-000, Brazil. E-mail: faleiros@ufmg.br Recently it has been shown that experimental distention of the small colon of horses promotes reduction of microvascular circulation and inflammation of the seromuscular layer associated with neutrophil accumulation in the lungs. However this model was not sufficient to induce evident histophatological changes in the mucosal layer. The aim of this study was to evaluate the mucosa subjected to that model of small colon distention by histomorphometry and scan electronic microscopy (SEM). Sixteen horses were used. In the distended group (DG), nine of them were subjected to distention of the small colon by a surgically implanted intraluminal balloon that was inflated with a pressure of 40mm Hg during 4 hours. In the sham-operated group (SG), the balloon was implanted but not inflated. Full-thickness intestinal samples were collected before and after obstruction and after 1.5 and 12 hours of decom-pression. By SEM, it was observed that the mucosa turned flat and smooth after distention and returned to the wrinkled original appearance after decompression. Twelve hours after decompression the mucosa had a more irregular appearance with points of fragmentation. There was a reduction in mucosa thickness after distention, returning to basal values after decompression. Instead of the fact that there were changes in appearance and thickness, it was concluded that the mucosa could borne up the compression caused by distention returning to the original characteristics without major lesions.

Abstract in English:

ABSTRACT.- Pilati C. & Barros C.S.L. 2007. [Experimental poisoning by Senecio brasiliensis (Asteraceae) in horses.] Intoxicação experimental por Senecio brasiliensis (Asteraceae) em eqüinos. Pesquisa Veterinária Brasileira 27(7):287-296. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Fourteen 4 to 22-year-old mixed breed horses weighing 230-475 kg were experimentally fed the dried aerial parts of Senecio brasiliensis (Spreng.) collected in its sprouting stage. A 15-year-old horse served as non-plant-fed control. Small amounts of the dried plant material were admixed in the ration given to the horses; larger amounts were grounded, admixed with water and force fed through nasogastric intubation. Liver biopsies were periodically performed in 11 horses. Nine horses died with signs or lesions of the poisoning after having received amounts of the plant corresponding to 0.87%, 1.5% (single administrations), 1.74% (two weekly administrations), 3.0% (three daily administrations), 7.42% (17 weekly administrations), 8.9% (284 daily administrations), 9.66% (82 daily administrations) and 9.30% (43 weekly administrations) of their body weight. Two horses which received amounts of the plant corresponding to 15.0% (30 and 60 daily administrations) of their body weight died during the experiments due to unrelated causes. Three horses which received amounts of the plant corresponding to 0.5% and 1.0% (single administrations), and 15.0% (240 daily administrations) of their body weight, and the control horse survived without any clinical signs. The disease induced by the plant had a clinical course of 1-30 days and was characterized by anorexia, jaundice and neurological signs of hepatic encephalopathy. Weight loss was observed in the more protracted cases. Necropsy findings included marked enhancement of the lobular pattern of the livers or those were firm and dark-red. Hemorrhages were frequent and more conspicuous on the subcutis, serosal surfaces and in the gastrointestinal mucosa. Edema occurred in the submucosa of the gastrointestinal tract and in body cavities. Histologically, the livers of horses that ingested relatively larger amounts of the plant for short periods of time had zonal coagulative necrosis and centrilobular to massive hemorrhages. Moderate to marked hepatomegalocytosis and mild to moderate fibrosis were seen in 4 horses which ingested small amounts of the plant for longer periods. Cholestasis and hemosiderosis were observed in the liver of 8 horses, neutrophilic aggregates in 6 and acidophilic intranuclear pseudo-inclusion bodies in hepatocytes of 3 horses. Changes suggestive of hepatic encephalopathy were observed in the brain of 6 horses. The earliest detected change in the liver biopsies was vacuolization of hepatocyte nuclei followed by apoptotic loss of hepatocytes, hepatomegalocytosis, infiltration of neutrophils and centrolobular necrosis. Occasionally hepatocellular acidophilic intranuclear pseudo-inclusion bodies and, in more protracted cases, slight fibrosis were seen. No changes were observed in the liver biopsies of the 3 plant-fed horses that survived, nor on the 2 horses that died of unrelated causes. The control horse had no clinical signs.

• Poisonous plants Senecio brasiliensis Asteraceae diseases of horses pathology

Abstract in Portuguese:

ABSTRACT.- Pilati C. & Barros C.S.L. 2007. [Experimental poisoning by Senecio brasiliensis (Asteraceae) in horses.] Intoxicação experimental por Senecio brasiliensis (Asteraceae) em eqüinos. Pesquisa Veterinária Brasileira 27(7):287-296. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Fourteen 4 to 22-year-old mixed breed horses weighing 230-475 kg were experimentally fed the dried aerial parts of Senecio brasiliensis (Spreng.) collected in its sprouting stage. A 15-year-old horse served as non-plant-fed control. Small amounts of the dried plant material were admixed in the ration given to the horses; larger amounts were grounded, admixed with water and force fed through nasogastric intubation. Liver biopsies were periodically performed in 11 horses. Nine horses died with signs or lesions of the poisoning after having received amounts of the plant corresponding to 0.87%, 1.5% (single administrations), 1.74% (two weekly administrations), 3.0% (three daily administrations), 7.42% (17 weekly administrations), 8.9% (284 daily administrations), 9.66% (82 daily administrations) and 9.30% (43 weekly administrations) of their body weight. Two horses which received amounts of the plant corresponding to 15.0% (30 and 60 daily administrations) of their body weight died during the experiments due to unrelated causes. Three horses which received amounts of the plant corresponding to 0.5% and 1.0% (single administrations), and 15.0% (240 daily administrations) of their body weight, and the control horse survived without any clinical signs. The disease induced by the plant had a clinical course of 1-30 days and was characterized by anorexia, jaundice and neurological signs of hepatic encephalopathy. Weight loss was observed in the more protracted cases. Necropsy findings included marked enhancement of the lobular pattern of the livers or those were firm and dark-red. Hemorrhages were frequent and more conspicuous on the subcutis, serosal surfaces and in the gastrointestinal mucosa. Edema occurred in the submucosa of the gastrointestinal tract and in body cavities. Histologically, the livers of horses that ingested relatively larger amounts of the plant for short periods of time had zonal coagulative necrosis and centrilobular to massive hemorrhages. Moderate to marked hepatomegalocytosis and mild to moderate fibrosis were seen in 4 horses which ingested small amounts of the plant for longer periods. Cholestasis and hemosiderosis were observed in the liver of 8 horses, neutrophilic aggregates in 6 and acidophilic intranuclear pseudo-inclusion bodies in hepatocytes of 3 horses. Changes suggestive of hepatic encephalopathy were observed in the brain of 6 horses. The earliest detected change in the liver biopsies was vacuolization of hepatocyte nuclei followed by apoptotic loss of hepatocytes, hepatomegalocytosis, infiltration of neutrophils and centrolobular necrosis. Occasionally hepatocellular acidophilic intranuclear pseudo-inclusion bodies and, in more protracted cases, slight fibrosis were seen. No changes were observed in the liver biopsies of the 3 plant-fed horses that survived, nor on the 2 horses that died of unrelated causes. The control horse had no clinical signs.

Abstract in English:

ABSTRACT.- Baldani C.D., Machado R.Z., Raso T.F. & Pinto A.A. 2007. Serodiagnosis of Babesia equi in horses submitted to exercise stress. Pesquisa Veterinária Brasileira27(4):179-183. Departamento de Patologia Veterinária, Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14870-000, Brazil. E-mail: zacarias@fcav.unesp.br A complement fixation test (CFT), performed in microtitre plates, based upon the use of crude antigenic preparation of Babesia equi was adapted for the detection of antibodies in serum of infected horses. The indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) were also used for the immunodiagnosis of B. equi. Serum samples from 15 apparently healthy horses, previously conditioned to a high-speed equine treadmill, were taken before and after exercise. All the samples analyzed were positive for B. equi infection. There were no significant differences (P<0.01) between these 3 tests, or the condition of rest or stress. The combined use of CFT and IFAT or ELISA should be recommended in order to enable veterinary services to more efficiently prevent introduction of infected horses into disease-free areas.

• Babesia equi diagnosis complement fixation indirect fluorescent antibody test enzyme-linked immunosorbent assay

Abstract in Portuguese:

ABSTRACT.- Baldani C.D., Machado R.Z., Raso T.F. & Pinto A.A. 2007. Serodiagnosis of Babesia equi in horses submitted to exercise stress. Pesquisa Veterinária Brasileira27(4):179-183. Departamento de Patologia Veterinária, Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14870-000, Brazil. E-mail: zacarias@fcav.unesp.br A complement fixation test (CFT), performed in microtitre plates, based upon the use of crude antigenic preparation of Babesia equi was adapted for the detection of antibodies in serum of infected horses. The indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) were also used for the immunodiagnosis of B. equi. Serum samples from 15 apparently healthy horses, previously conditioned to a high-speed equine treadmill, were taken before and after exercise. All the samples analyzed were positive for B. equi infection. There were no significant differences (P<0.01) between these 3 tests, or the condition of rest or stress. The combined use of CFT and IFAT or ELISA should be recommended in order to enable veterinary services to more efficiently prevent introduction of infected horses into disease-free areas.

Abstract in English:

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

• Poisonous plants Brachiaria humidicola plant poisoning photosensitization saponins horses

Abstract in Portuguese:

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

Abstract in English:

ABSTRACT.- Costa M.M., Machado S.A., Krewer C.C., Ilha M.R.S., Graça D.L., Guaraldi A.L.M. & Vargas A.C. 2006. Pathogenicity of Rhodococcus equi in mice, isolated from environment, human and horse clinical samples. Pesquisa Veterinária Brasileira 26(3):167-170. Laboratório de Bacteriologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Avenida Roraima 1000, Santa Maria, RS 97105-900, Brazil. E-mail: agueda@ccr.ufsm.br Rhodococcus equi is a facultative intracellular pathogen associated with bronchopneumonia, mesenteric lymphadenitis and enterocolitis in foals. Although R. equi is likely to be found in every horse-breeding farm, the clinical disease is unrecognized in most of them. Capsule components, equi factor, micolic acid and some products encoded by the large 85-90Kb plasmid were described as virulence factors. However, the pathogenesis of R. equi infections and the sensibility of foals are not completely understood. The aim of this study was evaluate the virulence of R. equi isolated from human, horses and environment for mices. Nine strains carrying the 85-90Kb plasmid isolated from foal clinical specimens, one from immunodeficient human patient and six plasmidless strains (four isolated from feces, one from pasture and one from immunodeficient human patient) were inoculated in cyclophosphamide immunossuppressed mice. The pathological changes and viability of R. equi cells in the liver of mice was verified after the 3rd, 6th an 10th day after inoculation for horse and environmental isolates and for R. equi isolates from human patients on the 1st, 3rd and 6th day. During the necropsy procedures, infiltrate of macrophages and pyogranulomatous lesions were detected after the sixth pos-inoculation day in the liver and spleen. In horse isolates, only plasmid positive strains were virulent, but in human isolates both strains (plasmid positive e plasmid negative) were virulent. Both groups of the immunossupressed mice inoculated with R. equi isolated from environment showed pathological changes. All R. equi strains were unable to kill non imunossuppressed mice.

• Rhodococcus equi mice virulence cyclophosphamide

Abstract in Portuguese:

ABSTRACT.- Costa M.M., Machado S.A., Krewer C.C., Ilha M.R.S., Graça D.L., Guaraldi A.L.M. & Vargas A.C. 2006. Pathogenicity of Rhodococcus equi in mice, isolated from environment, human and horse clinical samples. Pesquisa Veterinária Brasileira 26(3):167-170. Laboratório de Bacteriologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Avenida Roraima 1000, Santa Maria, RS 97105-900, Brazil. E-mail: agueda@ccr.ufsm.br Rhodococcus equi is a facultative intracellular pathogen associated with bronchopneumonia, mesenteric lymphadenitis and enterocolitis in foals. Although R. equi is likely to be found in every horse-breeding farm, the clinical disease is unrecognized in most of them. Capsule components, equi factor, micolic acid and some products encoded by the large 85-90Kb plasmid were described as virulence factors. However, the pathogenesis of R. equi infections and the sensibility of foals are not completely understood. The aim of this study was evaluate the virulence of R. equi isolated from human, horses and environment for mices. Nine strains carrying the 85-90Kb plasmid isolated from foal clinical specimens, one from immunodeficient human patient and six plasmidless strains (four isolated from feces, one from pasture and one from immunodeficient human patient) were inoculated in cyclophosphamide immunossuppressed mice. The pathological changes and viability of R. equi cells in the liver of mice was verified after the 3rd, 6th an 10th day after inoculation for horse and environmental isolates and for R. equi isolates from human patients on the 1st, 3rd and 6th day. During the necropsy procedures, infiltrate of macrophages and pyogranulomatous lesions were detected after the sixth pos-inoculation day in the liver and spleen. In horse isolates, only plasmid positive strains were virulent, but in human isolates both strains (plasmid positive e plasmid negative) were virulent. Both groups of the immunossupressed mice inoculated with R. equi isolated from environment showed pathological changes. All R. equi strains were unable to kill non imunossuppressed mice.

Abstract in English:

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

• Pythium insidiosum pythiosis ELISA horses rabbits.

Abstract in Portuguese:

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

Abstract in English:

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.