Hoose: I have been hearing of farms that have trouble with hoose, or lungworm, in weanlings. Autumn is the time when cattle are most at risk, and the mild conditions have lead to increased worm activity. Hoose is easily identified by a sharp, husky cough and animals having trouble breathing freely. Calves usually develop immunity after the first grazing season, but if exposure rates are low, older animals are still susceptible as they will not have developed adequate immunity.
The cycle of the lungworm starts when the animal ingests the larvae from the grass. These larvae then pass through the gut wall into the bloodstream, where they migrate to the lungs. There they mature and lay eggs within a week. The presence of the worms in the lungs causes inflammation and irritation to the weanlings. As such, the animal tries to cough up the lungworm to relieve the worm burden, they are then swallowed back down into the stomach where they can start the cycle again. Some worms will be passed in the dung, which is how the pasture becomes contaminated. Using a white or yellow drench will kill the lungworms present in the animal, but they do not provide any long term residual cover. Avermectin products will provide a much longer period of residual cover. If using a pour-on to treat cattle, make sure cattle are treated in dry conditions.