As the days get shorter and colder, the important job of housing is arriving. This is an ideal time to rid your animals of parasites. Cattle can pick up infections only while grazing at pasture. This is because the parasites are located on the pasture and cannot survive on silage. When cattle are housed, they cannot pick up new infections until turn out the following spring. Effective anthelmintic treatments at or during housing should deal with any parasitic problems until stock return to pasture next year. This year has been wet overall in many places providing ideal conditions for development of a number of parasites including stomach worms (Trichostrongylosis), lungworms or husk and liver fluke (Fascioliasis).
Trichostrongylosis (Ostertagiosis) is caused the roundworm family. One of the most notable parasites in this group is Trichostrongylus ostertagii. These parasites cause Parasitic Gastroenteritis (PGE), of which there are two types. Type 1 PGE is caused by the presence of large numbers of roundworms within the intestine. They feed on the intestinal lining, thereby depriving the bovine host of nutrients. Type 2 is caused by immature worms burrowing into the lining of the intestine and re-emerging in large numbers mid-winter. Type 1 PGE is most commonly encountered during the summer grazing season. These parasites typically develop from eggs to adults within 21-28 days (in warm weather 21 days is more common).
Lungworm or Husk (Dictyocauliasis) is caused by a roundworm which effectively lodges itself within the windpipes of the infected animal. This leads to obstruction of the airways, along with collapse of the air sacs (known as alveoli) within the lung. It is not uncommon for bacterial or viral pneumonia to develop secondary to lungworm infestation. Lungworm is most commonly seen in young grazing stock which, cough when excited or roused. The duration of the life cycle of these worms is similar to that of the roundworms. However, part of the development is spent on pasture within a cyst-like structure. Therefore, the immature worm can quite easily overwinter. This allows the infestation to persist from one grazing season to the next.
Liver fluke (Fascioliasis) is caused by a specific flatworm, known as Fasciola hepatica. This parasite has a life cycle with an intermediate host, the mud snail. It typically takes from 9-20 weeks to progress from beginning to end. Immature stages of the liver fluke are also able to survive in a cyst-like structure, in pasture, similar to Dictyocaulus. The encysted fluke can survive in this state for up to 2 years. This has knock on effects for control measures as it means that once fluke is established, control programmes must be followed year-in, year-out.
Fluke and worm infections can have a devastating economic effect on your cattle herd. Bimectin Plus is the recent addition to the Bimeda product range which can help you to control both. Bimectin plus contains Ivermectin and Clorsulon, two potent anthelmintic. Bimectin plus is potent in its effects against the roundworms and lungworm, including type 2 Ostertagiosis. Ivermectin affects these parasites by interfering with the function of their central nervous system. The parasites become unable to move and die of starvation. Clorsulon is a potent flukicide, causing adult liver fluke to become unable to metabolise sugar and to die of starvation. Timely use this powerful combination allows you to control adult liver fluke, stomach worms and lungworm in one injection.