With pastures so wet and grass a little short early in the growing season, producers should be watching for signs of liver fluke infections, said David Fernandez, Cooperative Extension Program livestock specialist at the University of Arkansas at Pine Bluff.
While rarely fatal in cattle, flukes can cause death in small ruminants. Liver flukes reduce the value of a carcass, thus lowering prices producers receive, he said.
Liver flukes are flatworms that invade the liver of livestock and cause liver damage. Liver flukes have a two-host life cycle. The eggs only hatch in water, so in wet years like this one, there are more problems with flukes, Fernandez said. The larvae infect a snail, where they develop and reproduce asexually. The larvae then exit the snail and encyst on nearby vegetation. When livestock eat the vegetation, they become infected.
The larvae migrate through the wall of the small intestine and into the liver. There, they tunnel through to the bile ducts. They damage the liver and can cause liver abscesses, a distended and painful abdomen, anemia and sudden death in sheep, Fernandez said. In lower numbers, they often mimic the signs of a barber pole worm infection. Flukes can also cause bottle jaw, poor condition, weight loss, fatigue and lower milk production.
Fernandez suggests: keep livestock out of areas where water accumulates; avoid pasturing animals in areas with snails in the grass; and mow pastures to remove cysts as encysted fluke larvae can remain viable for months if they do not dry out.
Treatment options include clorsulon, found in Ivomec Plus dewormer and albendazole (Valbazen) in the United States. Details: David Fernandez at 575-7214 or fernandezd@uapb.edu