PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Riet-Correa F., Andrade F.R.M., Carvalho F.K.L., Tabosa I.M., Galiza G.J., Bernardino N., Simões S.V.D. & Medeiros R.M.T. 2012. [Use of Prosopis juliflora pods as food for sheep and goats.] Utilização de vagens de Prosopis juliflora na alimentação de ovinos e caprinos. Pesquisa Veterinária Brasileira 32(10):987-989. Hospital Veterinário, Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, PB 58708-110, Brazil. E-mail: rmtmed@uol.com In Brazil, nervous signs caused by the ingestion of Prosopis juliflora pods have been reported in goats grazing in areas invaded by this plant. The disease has not been reported in sheep, but in this species, grazing in areas invaded by P. juliflora has been associated with the occurrence of malformations in lambs. The objective of this research was to study the toxicity for the central nervous system and the teratogenicity of P. juliflora pods in sheep, and to determine their toxicity to goats. Three experiments were performed. In Experiment 1, groups of four sheep were fed with ration containing 0, 60% or 90% of pods. In Experiment 2, seven sheep were fed with pods in amount equivalent to 2.1% body weight (bw) during the whole gestation. In Experiment 3, three goats were fed with pods in amounts equivalent to 1.5% of their bw during 264, 474, and 506 days. None of the experimental animals showed nervous signs and the seven pregnant sheep delivered normal lambs. These results suggest that P. juliflora pods can be used without restrictions in the food of sheep. Because in a previous paper P. juliflora pods, in the concentratiosn of 60% and 90% of the food, caused nervous signs in goats after 210 days of ingestion, it is suggested that there are variation in the toxicity of the pods. It is recommended that goats may be kept in areas invaded by P. juliflora for no more than one fructification period.

• Prosopis juliflora

Abstract in Portuguese:

RESUMO.- Riet-Correa F., Andrade F.R.M., Carvalho F.K.L., Tabosa I.M., Galiza G.J., Bernardino N., Simões S.V.D. & Medeiros R.M.T. 2012. [Use of Prosopis juliflora pods as food for sheep and goats.] Utilização de vagens de Prosopis juliflora na alimentação de ovinos e caprinos. Pesquisa Veterinária Brasileira 32(10):987-989. Hospital Veterinário, Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, PB 58708-110, Brazil. E-mail: rmtmed@uol.com Sinais nervosos associados à ingestão de vagens de Prosopis juliflora tem sido descritos em caprinos adultos pastejando continuamente em áreas invadidas por esta planta. A doença não tem sido constatada em ovinos, mas nesta espécie o pastejo em áreas invadidas por P. juliflora tem sido associado à ocorrência de malformações. O presente trabalho objetivou estudar a toxicidade sobre o sistema nervoso e o efeito teratogênico de vagens de P. juliflora (algaroba) em ovinos e avaliar a sua toxicidade em caprinos. Para isso foram realizados três experimentos. No Experimento 1, grupos de quatro ovinos receberam vagens na concentração de 0, 60% e 90% da alimentação durante um ano. No Experimento 2, sete ovelhas ingeriram vagens, em quantidades equivalente a 2,1% do peso corporal (pc) durante toda a gestação. No Experimento 3, três caprinos receberam vagens em quantidade equivalente a 1,5% do pc por períodos de 264, 474 e 506 dias. Nenhum animal experimental apresentou sinais nervosos e no Experimento 2 todas as ovelhas pariram cordeiros normais. Esses resultados sugerem que as vagens de algaroba podem ser utilizadas sem restrição na alimentação de ovinos. Em um trabalho anterior as vagens de algaroba, nas concentrações de 60% e 90% da alimentação, causaram intoxicação em caprinos após 210 dias de ingestão o que sugere que ocorrem variações na toxicidade das vagens. Recomenda-se que caprinos não permaneçam em áreas invadidas por algaroba por mais de um período de frutificação da planta.

Abstract in English:

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

• Perinatal mortality kids semiarid region Brazil.

Abstract in Portuguese:

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

Abstract in English:

Nóbrega Jr J.E., Riet-Correa F., Nóbrega R.S., Medeiros J.M., Vasconcelos J.S., Simões S.V.D. & Tabosa I.M. 2005. [Perinatal mortality of lambs in the semi-arid region of Paraíba, Brazil.] Mortalidade perinatal de cordeiros no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 25(3):171-178. Centro de Saúde e Tecnologia Rural, UFCG, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br The causes of perinatal lamb mortality were studied, from March 2002 to October 2004, on 27 farms in the semiarid region of Paraíba, northeastern Brazil. In 90 lambs necropsied the following frequency of different causes of death was found: neonatal infections (41.1%), malformations (23.3%), dystocia (10%), starvation/hypothermia (10%), abortion (4.4%), and predation (2.2%). Regarding the time of death, 4.4% of the lambs died before parturition, 10% during parturition, 30% on the first day after parturition, 20% between the second and the third day, and 35.6% between the 4th and the 28th day after parturition. The assistance during parturition, umbilical disinfection of the neonates, colostrum ingestion between 2 and 6 hours after parturition, and keeping the ewes in healthy environmental conditions during and after parturition could improve lamb surviving. The high frequency of malformations in different breeds suggests that malformations are due to a toxic plant. The main defects were permanent flexure of the front legs, brachygnathia, cleft palate, and other head malformations. In a recent report the authors demonstrated the teratogenic effects of Mimosa tenuiflora, a very common plant in the semiarid region, which is probably the cause of those malformations. Lambs which died due to starvation/hypothermia and had low birth weight (1.37 ± 0.70kg), suggesting that a better nutrition of the ewe during the last trimester of gestation is a way to control this cause of lamb mortality. Considering that in the northeastern region, in most farms, the rams stay with the ewes during the whole year, the adoption of a breeding season would help to control the different causes of perinatal lamb mortality.

• Lamb mortality newborn lambs sheep production perinatal mortality.

Abstract in Portuguese:

Nóbrega Jr J.E., Riet-Correa F., Nóbrega R.S., Medeiros J.M., Vasconcelos J.S., Simões S.V.D. & Tabosa I.M. 2005. [Perinatal mortality of lambs in the semi-arid region of Paraíba, Brazil.] Mortalidade perinatal de cordeiros no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 25(3):171-178. Centro de Saúde e Tecnologia Rural, UFCG, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br The causes of perinatal lamb mortality were studied, from March 2002 to October 2004, on 27 farms in the semiarid region of Paraíba, northeastern Brazil. In 90 lambs necropsied the following frequency of different causes of death was found: neonatal infections (41.1%), malformations (23.3%), dystocia (10%), starvation/hypothermia (10%), abortion (4.4%), and predation (2.2%). Regarding the time of death, 4.4% of the lambs died before parturition, 10% during parturition, 30% on the first day after parturition, 20% between the second and the third day, and 35.6% between the 4th and the 28th day after parturition. The assistance during parturition, umbilical disinfection of the neonates, colostrum ingestion between 2 and 6 hours after parturition, and keeping the ewes in healthy environmental conditions during and after parturition could improve lamb surviving. The high frequency of malformations in different breeds suggests that malformations are due to a toxic plant. The main defects were permanent flexure of the front legs, brachygnathia, cleft palate, and other head malformations. In a recent report the authors demonstrated the teratogenic effects of Mimosa tenuiflora, a very common plant in the semiarid region, which is probably the cause of those malformations. Lambs which died due to starvation/hypothermia and had low birth weight (1.37 ± 0.70kg), suggesting that a better nutrition of the ewe during the last trimester of gestation is a way to control this cause of lamb mortality. Considering that in the northeastern region, in most farms, the rams stay with the ewes during the whole year, the adoption of a breeding season would help to control the different causes of perinatal lamb mortality.

Abstract in English:

Lima E.F., Riet-Correa F., Tabosa I.M., Dantas A.F.M., Medeiros J.M. & Sucupira Júnior G. 2005. [Polioencephalomalacia in goats and sheep in the semiarid region of northeastern Brazil.] Polioencefalomalacia em caprinos e ovinos na região semi-árida do Nordeste do Brasil. Pesquisa Veterinária Brasileira 25(1):9-14. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br Seven outbreaks of polioencephalomalacia in goats and 3 in sheep are reported from the semiarid region of northeastern Brazil. Animals of different ages were affected in various seasons of the year. In 5 outbreaks the animals were supplemented with concentrate ration and in 5 others they were only grazing on pastures. In one outbreak sheep were supplemented with an energy-protein-mineral mixture containing 1.3% of sulfur flower. Clinical signs were characterized by blindness, depression, head pressing, circling, grinding of the teeth, incoordination, spastic paralysis, ataxia, depression of the palpebral and pupillary reflexes, lateral strabismus, nystagmus, and dilated pupils. Nine affected animals were treated with thiamine and dexamethasone; 7 of them recovered but 2 died. The diagnosis of the disease was based on the recovered animals after treatment and/or on the histologic lesions. The clinical course varied from 2 to 15 days. On three animals post-mortem examination was made. One had herniation of the cerebellum through the Foramen magnum and softening of the cerebral cortex. The cut surface of the cerebral cortex showed cavitation and yellowish discoloration. Another animal had only cerebellar herniation. In a third animal no gross lesions were observed. Histological changes in the 3 animals were laminar necrosis of the cerebral cortex, and in 2 malacia of the thalamus and the rostral colliculi was also observed. In 9 outbreaks the cause of the disease was not determined, but one was probably due to sulfur toxicosis caused by the high sulfur content of the energy-protein-mineral mixture containing 1.3% of sulfur flower (96% sulfur) and 30% chicken litter (0.39% sulfur).

• Polioencephalomalacia cortical necrosis goats sheep sulfur poisoning thiamine deficiency.

Abstract in Portuguese:

Lima E.F., Riet-Correa F., Tabosa I.M., Dantas A.F.M., Medeiros J.M. & Sucupira Júnior G. 2005. [Polioencephalomalacia in goats and sheep in the semiarid region of northeastern Brazil.] Polioencefalomalacia em caprinos e ovinos na região semi-árida do Nordeste do Brasil. Pesquisa Veterinária Brasileira 25(1):9-14. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: riet@cstr.ufcg.edu.br Seven outbreaks of polioencephalomalacia in goats and 3 in sheep are reported from the semiarid region of northeastern Brazil. Animals of different ages were affected in various seasons of the year. In 5 outbreaks the animals were supplemented with concentrate ration and in 5 others they were only grazing on pastures. In one outbreak sheep were supplemented with an energy-protein-mineral mixture containing 1.3% of sulfur flower. Clinical signs were characterized by blindness, depression, head pressing, circling, grinding of the teeth, incoordination, spastic paralysis, ataxia, depression of the palpebral and pupillary reflexes, lateral strabismus, nystagmus, and dilated pupils. Nine affected animals were treated with thiamine and dexamethasone; 7 of them recovered but 2 died. The diagnosis of the disease was based on the recovered animals after treatment and/or on the histologic lesions. The clinical course varied from 2 to 15 days. On three animals post-mortem examination was made. One had herniation of the cerebellum through the Foramen magnum and softening of the cerebral cortex. The cut surface of the cerebral cortex showed cavitation and yellowish discoloration. Another animal had only cerebellar herniation. In a third animal no gross lesions were observed. Histological changes in the 3 animals were laminar necrosis of the cerebral cortex, and in 2 malacia of the thalamus and the rostral colliculi was also observed. In 9 outbreaks the cause of the disease was not determined, but one was probably due to sulfur toxicosis caused by the high sulfur content of the energy-protein-mineral mixture containing 1.3% of sulfur flower (96% sulfur) and 30% chicken litter (0.39% sulfur).

Abstract in English:

Nobre V.M.T., Riet-Correa F., Barbosa Filho J.M., Dantas A.F.M., Tabosa I.M. & Vasconcelos J.S. 2004. [Poisoning by Crotalaria retusa (Fabaceae) in Equidae in the semiarid region of Paraíba.] Intoxicação por Crotalaria retusa (Fabaceae) em eqüídeos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 24(3):132-143. Depto Clínicas Veteri-nárias, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: verônica.nobre@uol.com.br From 2000 to 2003 eight cases of poisoning by Crotalaria retusa L. were observed in horses on 8 farms in the semiarid region of Paraíba and Ceará. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.

• Poisonous plants plant poisoning Crotalaria retusa Fabaceae hepatic cirrhosis horse pirrolizidine alkaloids.

Abstract in Portuguese:

Nobre V.M.T., Riet-Correa F., Barbosa Filho J.M., Dantas A.F.M., Tabosa I.M. & Vasconcelos J.S. 2004. [Poisoning by Crotalaria retusa (Fabaceae) in Equidae in the semiarid region of Paraíba.] Intoxicação por Crotalaria retusa (Fabaceae) em eqüídeos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 24(3):132-143. Depto Clínicas Veteri-nárias, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: verônica.nobre@uol.com.br From 2000 to 2003 eight cases of poisoning by Crotalaria retusa L. were observed in horses on 8 farms in the semiarid region of Paraíba and Ceará. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.

Abstract in English:

Riet-Correa F., Tabosa I.M., Vasconcelos J.S. & Medeiros J.M. 2004. [Floppy Kid Syndrome.] Síndrome do Cabrito Mole (“Floppy Kid”). Pesquisa Veterinária Brasileira 24(2):111-113. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB. E-mail: riet@cstr.ufcg.edu.br The Floppy Kid Syndrome is an acute disease of unknown cause, which affects 3 to 10 day-old kids. It is characterized by severe depression, flacid paralysis, dilatation of the abdomen and metabolic acidosis, without dehydration (paradoxical acidosis). The disease was decribed for the first time in the United States in 1987 and later in Canada and several countries in Europe (Tremblay et al. 1991, Meier 2002). This paper has the objective to show the characteristics of the disease, which already has been diagnosed in Paraíba and occurs probably in other states of Brazil, so that veterinarians and research workers could recognize it and give informations, which may clarify its etiology and pathogenic aspects. Additionally, the epidemiology, clinical signs and pathology of four outbreaks of floppy kid syndrome in Paraiba are reported.

• “Cabrito Mole” Floppy Kid goats acidosis.

Abstract in Portuguese:

Riet-Correa F., Tabosa I.M., Vasconcelos J.S. & Medeiros J.M. 2004. [Floppy Kid Syndrome.] Síndrome do Cabrito Mole (“Floppy Kid”). Pesquisa Veterinária Brasileira 24(2):111-113. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB. E-mail: riet@cstr.ufcg.edu.br The Floppy Kid Syndrome is an acute disease of unknown cause, which affects 3 to 10 day-old kids. It is characterized by severe depression, flacid paralysis, dilatation of the abdomen and metabolic acidosis, without dehydration (paradoxical acidosis). The disease was decribed for the first time in the United States in 1987 and later in Canada and several countries in Europe (Tremblay et al. 1991, Meier 2002). This paper has the objective to show the characteristics of the disease, which already has been diagnosed in Paraíba and occurs probably in other states of Brazil, so that veterinarians and research workers could recognize it and give informations, which may clarify its etiology and pathogenic aspects. Additionally, the epidemiology, clinical signs and pathology of four outbreaks of floppy kid syndrome in Paraiba are reported.

Abstract in English:

ABSTRACT.- Medeiros R.M.T., Riet-Correa F., Tabosa I.M., Silva Z.A., Barbosa R.C., Marques A.V.M.S. & Nogueira F.R.B. 2003. [Nitrate and nitrite poisoning in cattle caused by the ingestion of Echinochloa polystachya and Pennisetum purpureum in the semiarid region of the state of Paraíba.] Intoxicação por nitratos e nitritos em bovinos por ingestão de Echinochloa polystachya (capim-mandante) e Pennisetum purpureum (capim-elefante) no sertão da Paraíba. Pesquisa Veterinária Brasileira 23(1):17-20. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: rmtmed@cstr.ufpb.br Three outbreaks ofnitrate poisoning are reported from the semiarid region ofthe state of Paràíba, northeastem Brazil. One outbreak caused by Echinochloa polystachya (capim-mandante) and two others caused by Pennisetum purpureum (capim-elefante) occurred at the end ofthe dry season, after the first raios. ln one ofthe outbreaks caused by Pennisetum purpureum part of the pasture had been fertilized with cattle manure. Five out of 11 cattle died on one farm, 27 out of81 on another, and 3 out of9 on a third one. Clinicai sigos were anorexia, respiratory distress, teeth grinding, depression or hyperexitability, tremors, abdominal contractions, salívation, nasal discharge, uncoordinated gait, cyanosis, and finally recumbency. Nitrates and nitrites in the blood of affected cattle and pastures were determined by the diphenylamine test. It is suggested that the main reason for nitrate accumulation in the grasses was the prolonged draught followed by rain. ln one ofthe outbreaks caused by Pennisetum purpureum, another reason was probably the fertilization of the soil with cattle manure.

• Nitrate poisoning Echinochloa polystachya Pennisetum purpureum capim-elefante capim-mandante Intoxicação por nitratos.

Abstract in Portuguese:

RESUMO.- Medeiros R.M.T., Riet-Correa F., Tabosa I.M., Silva Z.A., Barbosa R.C., Marques A.V.M.S. & Nogueira F.R.B. 2003. [Nitrate and nitrite poisoning in cattle caused by the ingestion of Echinochloa polystachya and Pennisetum purpureum in the semiarid region of the state of Paraíba.] Intoxicação por nitratos e nitritos em bovinos por ingestão de Echinochloa polystachya (capim-mandante) e Pennisetum purpureum (capim-elefante) no sertão da Paraíba. Pesquisa Veterinária Brasileira 23(1):17-20. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: rmtmed@cstr.ufpb.br Descrevem-se três surtos de intoxicação por nitratos e nitritos em bovinos na região semi-árida do estado da Paraíba, nordeste do Brasil. O primeiro surto foi causado por Echinochloa polystachya (capim-mandante) e os demais por Pennisetum purpureum (capim-elefante) e ocorreram após um período prolongado de seca, após o início das primeiras chuvas. Em um dos surtos causado por Pennisetum purpureum, uma parte da área onde estava o pasto que continha níveis altos de nitratos havia sido fertilizada com esterco de bovino. No primeiro surto morreram 5 bovinos de um total de 11, no segundo morreram 21 de um total de 81 e no terceiro morreram 3 de um total de 19 bovinos. Os sinais clínicos se caracterizaram por anorexia, dispnéia, ranger de dentes, depressão ou hiperexitabilidade, tremores, contrações abdominais, salivação, corrimento nasal, andar cambaleante, mucosas cianóticas e, finalmente, decúbito. A presença de nitratos e nitritos foi detectada no sangue dos animais e nos pastos por meio da prova de difenilamina. Parece que o principal fator que determinou a concentração de altos níveis de nitratos nas plantas foi a ocorrência de chuvas depois de um longo período de seca. Outro fator importante no surto causado por Pennisetum purpureum foi a fertilização do solo com esterco.