Coccidiose em explorações pecuárias de pequenos ruminantes − estudo de casos em Trás-os-Montes
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2019-11-05
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A coccidiose é uma doença intestinal insidiosa provocada por protozoários do género Eimeria. Trata-se de uma das mais importantes doenças intestinais em ruminantes e tem um grande impacto económico em explorações de todo o mundo. A manifestação da doença ocorre maioritariamente em animais jovens, principalmente quando submetidos a fatores de stresse, levando ao aparecimento de sinais clínicos como diarreia, debilidade, inapetência ou perda de peso. Apesar de na maioria dos casos ser uma doença autolimitante pode estar associada a alguma mortalidade. Para além de planos profiláticos estratégicamente delineados, uma parte importante do controlo da disseminação da infeção deve passar pela implementação de boas práticas de higiene e maneio nas explorações. Como tal, foi levado a cabo este estudo no distrito de Bragança na região de Trásos-Montes que contou com a participação de 126 animais (119 ovinos e 7 caprinos) entre as 4 e as 6 semanas de idade, provenientes de 46 explorações diferentes. Para além de determinar a prevalência das diferentes espécies de Eimeria, foram avaliados diversos fatores relacionados com o maneio das explorações relativamente à associação com a presença de infeções maciças (OPG> 5 000) e identificação de espécies virulentas. Verificou-se que a espécie de Eimeria com maior prevalência em ovinos foi E. ovinoidalis (68,7%) e a com menor prevalência foi E. intricata (13,3%). Nos caprinos, E. ninakohlyakimovae foi a espécie com maior prevalência (100%) e E. alijevi (25%) menos frequente. Verificou-se que a fonte de água para abeberamento do rebanho influenciou o aparecimento de infeções maciças (p= 0,0232), sendo que nas explorações cuja água é proveniente da rede pública o risco de se desenvolverem infeções maciças é cerca de 3 vezes superior (OR= 2,922; IC 95%: 1,129- 7,555) comparativamente a explorações com outras fontes de água. Nas explorações onde há uma grande concentração de animais nos locais de abeberamento ocorrem significativamente (p< 0,001) mais infeções maciças, sendo que o risco de se desenvolverem estas infeções é quase 8 vezes (OR= 7,677; IC 95%: 2,729 – 21,589) superior do que nas explorações onde a concentração de animais junto aos pontos de água é inferior. Nas explorações onde não se recorre ao uso de antiparasitários, o risco de identificação de oocistos de espécies virulentas (p= 0,0065) de Eimeria é cerca de 12 vezes superior (OR= 12,167; IC 95%: 1,786- 82,864) quando comparado com as outras explorações.
Coccidiosis is an insidious gastrointestinal disease caused by protozoans of the genus Eimeria. The parasites os this genus have a high specificity regarding to the host. It´s one of the most important intestinal diseases in ruminants and it has a significant economic impact in farms all over the world. The manifestations of the disease occurs mostly among young animals when submited to stressful conditions leading to the appearence of clinical signs such as diarrhea, weakness, inappetence or weight loss. Even though most of the times it´s a self-limiting disease, it may be associated with some mortality. In addition to strategically designed prophylactic plans, an important part to control the spread of the infection is the implementation of good hygiene and management practices in farms. As such, this study was carried out in the district of Bragança, region of Trás-osMontes (northeastern Portugal) which included the participation of 126 animals between 4 and 6 weeks of age from 46 different farms. In addition to determining the prevalence of different species of Eimeria, several factors related to the management of farms were associated with the presence of massive infections (OPG> 5 000) and isolation of virulent species. It is concluded that the Eimeria species with the highest prevalence in sheep was E. ovinoidalis (68,7%) and the least prevalent E. intricata (13,30%). In the case of goats, E. ninakohlyakimovae was the species with the highest prevalence (100%) and E. alijevi (25%) with the lowest. It was also verified that the water source from which the herd drinks influences the appearance of massive infections (p= 0,0232), and in farms whose water comes from the public network, the probability of developing massive infections is almost 3 times higher (OR=2,922; IC 95%:1,129 – 7,555) than compared to the other farms with different water sources. In farms where it´s possible to verify a high concentration of animals near drinking spots, there are significantly (p< 0,001) more massive infections. The likelihooh of developing massive infections is almost 8 times higer (OR= 7,677; IC 95%: 2,729 – 21,589) than compared to the other farms. Moreover, in farms where the antiparasitic drugs aren´t used, the likelihood of isolating oocysts from virulent species of Eimeria (p= 0,0065) is almost 12 times higer (OR = 12.167, IC 95% : 1,786 - 82,864) compared to the other farms.
Coccidiosis is an insidious gastrointestinal disease caused by protozoans of the genus Eimeria. The parasites os this genus have a high specificity regarding to the host. It´s one of the most important intestinal diseases in ruminants and it has a significant economic impact in farms all over the world. The manifestations of the disease occurs mostly among young animals when submited to stressful conditions leading to the appearence of clinical signs such as diarrhea, weakness, inappetence or weight loss. Even though most of the times it´s a self-limiting disease, it may be associated with some mortality. In addition to strategically designed prophylactic plans, an important part to control the spread of the infection is the implementation of good hygiene and management practices in farms. As such, this study was carried out in the district of Bragança, region of Trás-osMontes (northeastern Portugal) which included the participation of 126 animals between 4 and 6 weeks of age from 46 different farms. In addition to determining the prevalence of different species of Eimeria, several factors related to the management of farms were associated with the presence of massive infections (OPG> 5 000) and isolation of virulent species. It is concluded that the Eimeria species with the highest prevalence in sheep was E. ovinoidalis (68,7%) and the least prevalent E. intricata (13,30%). In the case of goats, E. ninakohlyakimovae was the species with the highest prevalence (100%) and E. alijevi (25%) with the lowest. It was also verified that the water source from which the herd drinks influences the appearance of massive infections (p= 0,0232), and in farms whose water comes from the public network, the probability of developing massive infections is almost 3 times higher (OR=2,922; IC 95%:1,129 – 7,555) than compared to the other farms with different water sources. In farms where it´s possible to verify a high concentration of animals near drinking spots, there are significantly (p< 0,001) more massive infections. The likelihooh of developing massive infections is almost 8 times higer (OR= 7,677; IC 95%: 2,729 – 21,589) than compared to the other farms. Moreover, in farms where the antiparasitic drugs aren´t used, the likelihood of isolating oocysts from virulent species of Eimeria (p= 0,0065) is almost 12 times higer (OR = 12.167, IC 95% : 1,786 - 82,864) compared to the other farms.
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Dissertação de Mestrado Integrado em Medicina Veterinária
Palavras-chave
coccidiose , Eimeria