PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Karam F.S.C., Soares M.P., Haraguchi M., Riet-Correa F., Méndez M.C. & Jarenkow J.A. 2004. [Epidemiological aspects of seneciosis in southern Rio Grande do Sul, Brazil.] Aspectos epidemiológicos da seneciose na região sul do Rio Grande do Sul, Brasil. Pesquisa Veterinária Brasileira 24(4):191-198. Laboratório de Toxicologia, Faculdade de Medicina Veterinária, URCAMP, Bagé, RS 96400-110, Brazil. E-mail: fernando@alternet.com.br Seneciosis is the main cause of livestock mortality due to poisonous plants in the State of Rio Grande do Sul, Brazil. This paper presents epidemiological data of 24 outbreaks in cattle and one in horses, diagnosed by the Regional Diagnostic Laboratory at Pelotas University in southern Rio Grande do Sul, from 1998 to 2000. Additionally, data of 54 outbreaks which occurred in 1978-1997 were analyzed. The farms where outbreaks occurred in 1998-2000 were visited to obtain clinical and epidemiological data and to verify the presence of Senecio spp. Eleven outbreaks (45.83%) affected cattle up to 3 years of age, and 13 (54.16%) cattle over 3 years. Nine (37.5%) outbreaks affected females and 15 (62.5%) males. Ten (41.66%) outbreaks occurred in spring, 4 (16.66%) in summer, 5 (20.83%) in autumn, and 5 (20.83%) in winter. Morbidity rate was estimated with 4.92% and case fatality with 95.59%. The predomionating Senecio species were S. brasiliensis on 12 farms (57.14%), S. selloi on 10 (47.61%), S. oxyphyllus on 6 (28.57%), S. heterotrichius on 3 (14.28%), and S. leptolobus on 1 farm (4.76%). The main clinical signs were progressive emaciation, incoordination, diarrhea, tenesmus, rectal prolapse and aggressiveness. The clinical manifestation periods of affected cattle observed during the farm visits, or of cattle sent for post-mortem examination,were 24-96 hours in 4 outbreaks (16.66%), 4-7 days in 7 (29.16%), 1-2 weeks in 4 (16.66%), 2-3 weeks in 2 (8.33%), 1-2 months in 2 (8.33%), and 2-3 months in 1 outbreak (4.16%). In 4 outbreaks (16.66%) the clinical manifestation period was not established. In outbreaks with longer clinical manifestation periods some animals showed photosensitization. The main necropsy findings were a hard and enlarged liver, distended gall bladder, edema of the mesenterium and abomasum, and increased amount of liquid in the cavities. Histopathological findings were fibroplasia, megalocytosis and biliary ductal proliferation of the liver, and spongy degeneration of the cerebral white matter. Samples of different Senecio species, in different seasons, were analyzed for detection of pyrrolizidine alkaloids (PAs) by thin layer chromatography. Retrorsine was found in Senecio brasiliensis, S. heterotrichius, S. selloi and S. oxyphyllus. In S. brasiliensis and S. heterotrichius one and two more non-identified PAs were detected, respectively. The total PAs concentration by spectrophotometric method was 0.25% for S. brasiliensis, 0.19% for S. heterotrichius, 0.03% for S. oxyphyllus, and 0.03% for S. selloi. The highest PAs concentration occurred in winter (June/July). No alkaloids were found in samples of S. leptolobus. These results show that S. brasiliensis is the most important cause of seneciosis in southern Rio Grande do Sul. Additional data obtained dealt with 54 outbreaks of PAs poisoning in 1978-1997. During this period, 7 outbreaks (12.96%) affected cattle up to 3 years of age, 39 (72.22%) cattle over 3 years, and 3 outbreaks (5.55%) affected cattle of different ages. In 5 outbreaks (9.25%) the age was not informed. Seven outbreaks (12.96%) affected males, 39 (72.22%) females, 3 (5.55%) both sexes, and in 5 outbreaks (9.25%) the sex was not informed. Twenty-three outbreaks (42.59%) occurred in spring, 9 (16.66%) in summer, 9 (16.66%) in autumn, and 13 (24.07%) in winter. The greater number of outbreaks during 1998-2000 (24 outbreaks in 3 years) in regard to 1978-1997 (54 outbreaks in 20 years) is probably due to a decrease of more than 50% in the number of sheep in the region.

• Seneciosis epidemiology poisonous plants Senecio spp Asteraceae pyrrolizidine alkaloids cattle.

Abstract in Portuguese:

Karam F.S.C., Soares M.P., Haraguchi M., Riet-Correa F., Méndez M.C. & Jarenkow J.A. 2004. [Epidemiological aspects of seneciosis in southern Rio Grande do Sul, Brazil.] Aspectos epidemiológicos da seneciose na região sul do Rio Grande do Sul, Brasil. Pesquisa Veterinária Brasileira 24(4):191-198. Laboratório de Toxicologia, Faculdade de Medicina Veterinária, URCAMP, Bagé, RS 96400-110, Brazil. E-mail: fernando@alternet.com.br Seneciosis is the main cause of livestock mortality due to poisonous plants in the State of Rio Grande do Sul, Brazil. This paper presents epidemiological data of 24 outbreaks in cattle and one in horses, diagnosed by the Regional Diagnostic Laboratory at Pelotas University in southern Rio Grande do Sul, from 1998 to 2000. Additionally, data of 54 outbreaks which occurred in 1978-1997 were analyzed. The farms where outbreaks occurred in 1998-2000 were visited to obtain clinical and epidemiological data and to verify the presence of Senecio spp. Eleven outbreaks (45.83%) affected cattle up to 3 years of age, and 13 (54.16%) cattle over 3 years. Nine (37.5%) outbreaks affected females and 15 (62.5%) males. Ten (41.66%) outbreaks occurred in spring, 4 (16.66%) in summer, 5 (20.83%) in autumn, and 5 (20.83%) in winter. Morbidity rate was estimated with 4.92% and case fatality with 95.59%. The predomionating Senecio species were S. brasiliensis on 12 farms (57.14%), S. selloi on 10 (47.61%), S. oxyphyllus on 6 (28.57%), S. heterotrichius on 3 (14.28%), and S. leptolobus on 1 farm (4.76%). The main clinical signs were progressive emaciation, incoordination, diarrhea, tenesmus, rectal prolapse and aggressiveness. The clinical manifestation periods of affected cattle observed during the farm visits, or of cattle sent for post-mortem examination,were 24-96 hours in 4 outbreaks (16.66%), 4-7 days in 7 (29.16%), 1-2 weeks in 4 (16.66%), 2-3 weeks in 2 (8.33%), 1-2 months in 2 (8.33%), and 2-3 months in 1 outbreak (4.16%). In 4 outbreaks (16.66%) the clinical manifestation period was not established. In outbreaks with longer clinical manifestation periods some animals showed photosensitization. The main necropsy findings were a hard and enlarged liver, distended gall bladder, edema of the mesenterium and abomasum, and increased amount of liquid in the cavities. Histopathological findings were fibroplasia, megalocytosis and biliary ductal proliferation of the liver, and spongy degeneration of the cerebral white matter. Samples of different Senecio species, in different seasons, were analyzed for detection of pyrrolizidine alkaloids (PAs) by thin layer chromatography. Retrorsine was found in Senecio brasiliensis, S. heterotrichius, S. selloi and S. oxyphyllus. In S. brasiliensis and S. heterotrichius one and two more non-identified PAs were detected, respectively. The total PAs concentration by spectrophotometric method was 0.25% for S. brasiliensis, 0.19% for S. heterotrichius, 0.03% for S. oxyphyllus, and 0.03% for S. selloi. The highest PAs concentration occurred in winter (June/July). No alkaloids were found in samples of S. leptolobus. These results show that S. brasiliensis is the most important cause of seneciosis in southern Rio Grande do Sul. Additional data obtained dealt with 54 outbreaks of PAs poisoning in 1978-1997. During this period, 7 outbreaks (12.96%) affected cattle up to 3 years of age, 39 (72.22%) cattle over 3 years, and 3 outbreaks (5.55%) affected cattle of different ages. In 5 outbreaks (9.25%) the age was not informed. Seven outbreaks (12.96%) affected males, 39 (72.22%) females, 3 (5.55%) both sexes, and in 5 outbreaks (9.25%) the sex was not informed. Twenty-three outbreaks (42.59%) occurred in spring, 9 (16.66%) in summer, 9 (16.66%) in autumn, and 13 (24.07%) in winter. The greater number of outbreaks during 1998-2000 (24 outbreaks in 3 years) in regard to 1978-1997 (54 outbreaks in 20 years) is probably due to a decrease of more than 50% in the number of sheep in the region.

Abstract in English:

ABSTRACT.- Karam F.S.C., Méndez M.C., Jarenkow j.A. & Riet-Correa F. 2002. [Phenology of four poisonous Senecio (Asteraceae) species in southern Rio Grande do Sul, Brazil.] Fenologia de quatro espécies tóxicas de Senecio (Asteraceae) na região Sul do Rio Grande do Sul. Pesquisa Veterinária Brasileira 22(1):33-39. Laboratório de Toxicologia, Fac. Med. Vet., URCAMP, Bagé, RS 96400-110, Brazil. E-mail: fernando@alternet.com.br This study aimed to determine the phenology of Senecio brasiliensis, S. oxyphyllus, S. heterotrichius and S. selloi, and their relationship with cattle poisoning in the southern region of the State of Rio Grande do Sul, Brazil. The phenology was studied during two years in the rural area of the municipalities of Bagé and Capão do Leão. These phenological observations were made at monthly intervals during the vegetative phase, and every 15 days during the reproductive period. The plants were observed from emergence until the dispersai of seeds, considering their vigor and their relationship with environmental factors. The results indicate that whenever the environmental conditions, like moisture and light, were favorable, Senecio spp emerge. The vegetative phenophases are practically constant during ali life cycle of the plant and the whole yea1: Unfavorable environmental factors like water stress, soil management and damage by insects, associated or not, can alter the cycle of the plants and determine their permanence in the environment. The majority of the species studied behaved like annual and monocarpic plants. According with the permanence during the two years of observation, the most persistent species in the environmentwas S. heterotrichius (15% of the plants persisted during the two year period), followed by S. selloi (2,8%) and S. brasiliensis (0,9%). S. oxyphyllus did not persist for more than one year.

• Phenology poisonous plants Senecio brasiliensis Senecio oxyphyllus Senecio heterotrichius Senecio selloi Asteraceae Fenologia plantas tóxicas.

Abstract in Portuguese:

RESUMO.- Karam F.S.C., Méndez M.C., Jarenkow j.A. & Riet-Correa F. 2002. [Phenology of four poisonous Senecio (Asteraceae) species in southern Rio Grande do Sul, Brazil.] Fenologia de quatro espécies tóxicas de Senecio (Asteraceae) na região Sul do Rio Grande do Sul. Pesquisa Veterinária Brasileira 22(1):33-39. Laboratório de Toxicologia, Fac. Med. Vet., URCAMP, Bagé, RS 96400-110, Brazil. E-mail: fernando@alternet.com.br O objetivo principal desse trabalho foi determinara fenologia de Senecio brasiliensis, S. oxyphyllus, S. heterotrichius e S. selloi, e relacioná-la com a epidemiologia da intoxicação em bovinos, na região sul do Rio Grande do Sul. O estudo fenológico foi feito durante dois anos nos municípios de Bagé e Capão do Leão. As leituras foram mensais durante o período vegetativo e quinzenais no período reprodutivo das espécies, para observação desde sua emergência até dispersão de sementes, avaliando-se o vigor, e relacionando essas variáveis com fatores ambientais. Os resultados permitiram concluir que durante todo o ano há emergência de plantas de Senecio spp, desde que haja condições ambientais favoráveis, como umidade e luz, e as fenofases vegetativas são praticamente constantes durante todo o ciclo da planta. Fatores ambientais desfavoráveis como o déficit hídrico, o manejo do solo e o dano de insetos, associados ou não, podem alterar o ciclo das plantas e serem determinantes para a sua permanência no ambiente. A maioria dos exemplares, das quatro espécies, comportou-se como anual e monocárpica. A espécie mais persistente no ambiente foi S. heterotrichius (15% das plantas persistiram durante os dois anos de estudo), seguida de S. selloi (2,8%} e S. brasiliensis (0,9%). S. oxyphyllus não permaneceu no ambiente por mais de um ano.