Eimeria spp. infection in lambs from southern Brazil / Infecção por Eimeria spp. em cordeiros do sul do Brasil

Eimeria infections are common in the sheep industry worldwide. Lambs are more susceptible to coccidiosis, especially in stressful conditions, being infected by different species of the parasite. Eimeria crandallis and Eimeria ovinoidalis are considered the most pathogenic, causing reduced growth, dehydration, anorexia, and death. In this study, the frequency of Eimeria species was evaluated in lambs from the southern region of the Rio Grande do Sul state, Brazil. Fecal samples from 248 lambs, from 19 farms, were tested for the presence of oocysts. The positive samples were re-examined and the sporulated oocysts analyzed morphometrically to identify the presence of Eimeria species. In 100% of the evaluated farms, there were animals positive for the protozoan. The frequency of Eimeria species was: E. ovinoidalis (94.74%), E. crandallis (89.47%), E. granulosa (78.95%), E. parva (68.42%), E. ahsata (63.13%), E. punctata (42.11%), E. bakuensis (36.84%), E. faurei (10.53%), and E. pallida (5.26%). Mixed infection was found in 94.74% of the samples. This research describes, for the first time, the occurrence of E. crandallis and E. ovinoidalis infecting lambs in the study area. The wide distribution of this protozoan and the high frequency of pathogenic species show the importance and potential damage of sheep coccidiosis in herds from Rio Grande do Sul.(AU)

As infecções por Eimeria são comuns na ovinocultura mundial. Cordeiros são mais suscetíveis a coccidiose, especialmente em condições estressantes, sendo infectados por diferentes espécies do parasito. Eimeria crandallis e Eimeria ovinoidalis são consideradas as mais patogênicas, causando redução do crescimento, desidratação, anorexia e morte. Neste estudo, a prevalência de Eimeria spp. foi avaliada em cordeiros da região sul do Estado do Rio Grande do Sul, Brasil. Amostras fecais de 248 cordeiros, provenientes de 19 fazendas, foram testadas quanto à presença de oocistos. As amostras positivas foram reexaminadas e os oocistos esporulados analisados morfometricamente para identificação das espécies de Eimeria presentes. Em 100% das fazendas avaliadas houve animais positivos para o protozoário. A frequência das espécies de Eimeria foi: E. ovinoidalis (94.74%), E. crandallis (89.47%), E. granulosa (78.95%), E. parva (68.42%), E. ahsata (63.13%), E. punctata (42.11%), E. bakuensis (36.84%), E. faurei (10.53%) e E. pallida (5.26). Infecção mista foi encontrada em 94.74% das amostras. Este trabalho descreve pela primeira vez a ocorrência de E. crandallis e E. ovinoidalis infectando cordeiros na área de estudo. Este trabalho descreve pela primeira vez a ocorrência de E. crandallis e E. ovinoidalis infectando cordeiros na área de estudo. A ampla distribuição desse protozoário e a alta frequência das espécies patogênicas evidenciam a importância da coccidiose ovina e os danos potenciais nos rebanhos do Rio Grande do Sul.(AU)

Occurrence of antibodies to Toxoplasma gondii in water buffaloes and meat cattle in Rio Grande do Sul State, southern Brazil.

Serum samples from 169 water buffaloes and 121 beef cattle were analyzed for antibodies to T. gondii by an indirect fluorescent antibody test (IFAT). Positive results were obtained in 27.2% of water buffaloes and 17.4% of cattle. Statistical analysis indicated significant differences between the prevalence in cattle and buffalo (p ≤ 0.05). The highest titres found in positive animals were 1:256 (buffaloes) and 1:64 (cattle). In both bovine species, toxoplasmosis frequency in young animals (less than 2 years old) was lower compared to older individuals, although the differences seen in cattle were not statistically significant.

Acute fasciolosis in cattle in southern Brazil / Fasciolose aguda em bovinos no Sul do Brasil

This study describes the epidemiological and pathological aspects of an outbreak of acute fasciolosis in cattle in southern Brazil. Fifteen out of 70 three-year-old pregnant cows lost weight in the 30-40 days prior to calving. Clinical signs included diarrhea, weakness, mild anemia and jaundice. Dark yellow fluid in the abdominal cavity was observed at necropsy. Fibrin and clotted blood were adhered to the pericardium and lung, primarily in the diaphragmatic lobes. The liver was enlarged, and the capsular surface was irregular with clear areas and petechiae. At the cut surface, the liver was irregular, firm and edematous, and several hemorrhagic channels could be observed. Areas of fibrosis through the parenchyma and whitish thrombi occluding the great vessels were also observed. The livers of 10 cows that not died were condemned at slaughter for lesions of fasciolosis similar to those observed at necropsy. Microscopically, the liver showed areas of coagulation necrosis, extensive hemorrhages in the streaks or foci and disruption of the parenchyma with neutrophil and eosinophil infiltration. Fibrosis and bile duct proliferation were also observed. Immature Fasciola hepatica flukes were observed in the parenchyma surrounded by degenerated hepatocytes, neutrophils, eosinophils, and hemorrhages. The outbreak occurred on a farm located in an area endemic for fasciolosis, although the acute form of the disease is not common in cattle in this region. It is likely that the cows were infected by F. hepatica metacercariae released in the late fall or early spring in the rice stubble where the herd was grazing prior to calving. Although mortality due to fasciolosis in cattle is infrequent, outbreaks can occur and treatments that are effective in both the immature and adult forms of the parasite should be administered to prevent economic losses.

Descrevem-se os aspectos epidemiológicos e patológicos de um surto de fasciolose aguda diagnosticado em bovinos na região sul do Rio Grande do Sul. De um lote de 70 vacas de três anos de idade 15 apresentaram perda de peso 30-40 dias antes da parição. Dessas, 10 vacas abortaram e 5 morreram. Os sinais clínicos caracterizaram-se por diarreia, fraqueza, anemia discreta e icterícia. Na necropsia havia líquido escuro na cavidade abdominal. Na cavidade torácica havia fibrina e coágulos de sangue aderidos ao pericárdio e pulmões, principalmente nos lobos diafragmáticos. O fígado estava aumentado de tamanho e a superfície capsular estava irregular com áreas claras e petéquias. A superfície de corte estava irregular, firme e edematosa e podiam ser observadas estrias hemorrágicas através do parênquima. Áreas de fibrose e trombos esbranquiçados ocluindo vasos sanguíneos foram, também, observados. Os fígados das 10 vacas que não morreram foram condenados no abate por lesões de fasciolose similares às observadas na necropsia. Microscopicamente, o fígado apresentava áreas de necrose de coagulação, focos de hemorragia acentuada e desorganização do parênquima com acentuada infiltração de neutrófilos e eosinófilos. Havia, ainda, fibrose e hiperplasia de células de ductos biliares. Formas imaturas de Fasciola hepatica foram observadas no parênquima rodeadas por hepatócitos em degeneração, neutrófilos e eosinófilos, e hemorragia. O surto ocorreu em uma propriedade localizada em uma área endêmica para a fasciolose, embora a forma aguda da enfermidade não seja frequente em bovinos nesta região. É provável que as vacas tenham se infectado pelas metacercárias liberadas do hospedeiro intermediário no final do outono ou no início da primavera na resteva de arroz onde foram colocadas antes da parição. Embora mortalidade em bovinos devido à fasciolose seja infrequente, surtos podem ocorrer e a utilização de fasciolicidas eficientes para controlar as formas imaturas ou adultas deste parasita devem ser administradas aos bovinos para evitar eventuais perdas econômicas.

Subacute and acute fasciolosis in sheep in southern Brazil.

Eight outbreaks of acute and subacute fasciolosis are reported in sheep in the municipality of Santa Vitória do Palmar, southern Brazil, in areas used for irrigated rice cultivation, which are subject to frequent flooding. Two outbreaks occurred mid-winter during July and August, and six occurred during spring and early summer. Morbidity ranged from 3 to 66.7 %, and mortality ranged from 3 to 50 %. Clinical signs included weight loss, mucosal pallor, apathy, depression, muscle tremors, and drooling; these were followed by death within approximately 24 h. Some sheep were found dead. Gross lesions were characterized by an irregular liver capsule with fibrin deposition and hemorrhages. The liver parenchyma contained hemorrhagic tracts or irregular clear areas alternated with dark hemorrhagic areas. Histologically, hemorrhagic dark red tracts of necrotic liver parenchyma and an inflammatory infiltrate were noted; these lesions coincided with the presence of immature flukes. Langhans-type giant cells, fibrous tissue, and bile duct cell proliferation were observed in subacute cases. Chronic fasciolosis is a well-known disease to farmers in southern Brazil; nevertheless, acute and subacute fasciolosis, which are more difficult to diagnose and treat, may cause important economic losses. Efficient control of fasciolosis requires integration of measures to treat infections in the definitive host, to reduce the population of snails of the genus Lymnaea, and to avoid contact between the parasite and host by appropriate pasture management.

[Helminths of Pampas fox, Pseudalopex gymnocercus (Fischer, 1814) and of Crab-eating fox, Cerdocyon thous (Linnaeus, 1766) in the South of the State of Rio Grande do Sul, Brazil]. / Helmintos do cachorro do campo, Pseudalopex gymnocercus (Fischer, 1814) e do cachorro do mato, Cerdocyon thous (Linnaeus, 1766) no sul do estado do Rio Grande do Sul, Brasil.

Forty wild canids were captured by live trap at Municipalities of Pedro Osorio and Pelotas in Southern of the State of Rio Grande do Sul and they were transported to the Parasitology Laboratory at the Universidade Federal de Pelotas. After they were posted, segments of intestinal, respiratory and urinary tracts and liver were separated and examined. Animal skulls were used for taxonomic identification. Of forty wild animals trapped, 22 (55%) were Pseudalopex gymnocercus and 22 (55%) Cerdocyon thous. The most prevalent nematodes were: Ancylostoma caninum (45.4 in P. gymnocercus and 22.2% in C. thous), Molineus felineus (9.9 in P. gymnocercus and 5.6% in C. thous), Strongyloides sp. (22.7 in P. gymnocercus and 16.7% in C. thous), Trichuris sp. (13.6 in P. gymnocercus and 11.1% in C. thous), and Capillaria hepatica (13.6 in P. gymnocercus and 5.5% in C. thous). The trematodes observed were: Alaria alata (36.4 in P. gymnocercus and 50.0% in C. thous), and Asthemia heterolecithodes in 5.6% C. thous. Cestodes were identified as Spirometra sp. (61.1% in C. thous and 54.5 in P. gymnocercus), Diphyllobothriidae, (81.8 in P. gymnocercus and 77.8% in C. thous) and an Acantocephala of the genus Centrorhynchus was also observed in 5.6% of C. thous only. These results indicated the helminths fauna in wild canids from the studied area.