Parasites can come from pet stores, and trade shows. Parasites are common in wild caught animals. Poor cleaning prcatices can lead to infections. If one snake in your collection is harboring parasites, not properly isolating them, or cleanin and dissinfecting yourself after cleaning and handling them could spread them. Housing more than one snake in the same environment could also cause the spread. Sometimes segement of a parasite such as a tapeworm could be seen in poop. Other parasite can not. Depending on the parasite, you might not see ill effects for some time. It is best to take in a fecal sample of all new snakes, and try and do fecals on a yearly basis to make sure your snakes are staying healthy. This is done for dogs and cats, so why not snakes. Before treatment you would need to know the parasite. A vet can examine your snake and do a fecal exam. If parasties are present the type of parasite and size of your snake will determine what medicine and the amount used. Hope this helps you some.