Acute fasciolosis in cattle in southern Brazil

Abstract

Pesq. Vet. Bras. 33(6) 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.

Doenças parasitárias em bovinos e ovinos no sul do Brasil: frequência e estimativa de perdas econômicas

“…Fasciolose crônica em bovinos jovens pode ocorrer eventualmente com sinais clínicos de emagrecimento, diarreia e edema submandibular e as perdas econômicas ocorrem, majoritariamente, devido a doença subclínica (Lotfollahzadeh et al 2008). Um surto de fasciolose aguda em vacas com cria ao pé criadas a campo foi descrito em área endêmica na região deste estudo (Adrien et al 2013).…”

Epidemiological and clinical-pathological aspects of fasciolosis in livers of cattle slaughtered in southern Brazil

“…Overall, adult cattle do not develop apparent clinical signs after mild infections, but some studies have reported that infected animals may present diminished carcass yield and decreased reproduction and milk production indexes, causing economic losses throughout their lives (Gajewska et al 2005, Petros et al 2013, Andreani et al 2017. The acute form of the disease is seldom reported in adult cattle; however, in an area considered endemic in Rio Grande do Sul state, of a batch of 70 cows aged approximately 3 years, 10 animals aborted and five died with clinical signs and lesions characteristic of acute fasciolosis (Adrien et al 2013).…”

“…Fasciolosis can present with acute, subacute or chronic form (Müller 2007). There may also be multiple 0.5-5 mm red areas distributed randomly in the hepatic parenchyma, irregular at cut, firm and edematous, and with hemorrhage in the bile ducts and fibrosis in the parenchyma (Adrien et al 2013. Animals may present with anemia, jaundice, distended gallbladder with thick edematous wall and multiple Fasciola hepatica specimens at different stages in its interior and spread in the hepatic parenchyma (Adrien et al 2013).…”

“…There may also be multiple 0.5-5 mm red areas distributed randomly in the hepatic parenchyma, irregular at cut, firm and edematous, and with hemorrhage in the bile ducts and fibrosis in the parenchyma (Adrien et al 2013. Animals may present with anemia, jaundice, distended gallbladder with thick edematous wall and multiple Fasciola hepatica specimens at different stages in its interior and spread in the hepatic parenchyma (Adrien et al 2013). The acute form is responsible for the death of young sheep and cattle, and can cause developmental deficit and generate costs with treatments (Adrien et al 2013, Andreani et al 2017.…”

“…Animals may present with anemia, jaundice, distended gallbladder with thick edematous wall and multiple Fasciola hepatica specimens at different stages in its interior and spread in the hepatic parenchyma (Adrien et al 2013). The acute form is responsible for the death of young sheep and cattle, and can cause developmental deficit and generate costs with treatments (Adrien et al 2013, Andreani et al 2017.…”