When to deworm your Sheltie Sheltie can start his first deworming at 2 months of age, usually one week before the vaccination. After deworming, observe the dog’s stool and if parasites are found, deworm again every other week to ensure that the worms are removed before vaccination. Deworming medication is available in the form of in vitro and in vivo drops, such as Dashera, which can repel parasites such as roundworms, hookworms, mange mites, hoppers and lice, as well as prevent heartworm. In vivo is usually once every one to three months and in vitro once a month.
