Researchers at the University of Guelph are now cautioning dog owners about a potentially deadly tapeworm in Ontario that can infect both dogs and their the owners. According to a recent study by the Centre For Disease Control, the worm was first discovered in the province after five dogs in the western region of Lake Ontario fell ill between the years of 2012 and 2016. Now, signs of the tapeworm are starting to appear in southern Ontario as well, the Toronto Star reports.\nThe tapeworm ultimately leads to the development of a disease called Alveolar echinococcosis (AE), which can kill the host if left untreated.\n"The disease caused by infection with the intermediate stage of the Echinococcus multilocularis tapeworm, is typically fatal in humans and dogs when left untreated. Since 2012, alveolar echinococcosis has been diagnosed in 5 dogs, 3 lemurs, and 1 chipmunk in southern Ontario, Canada, a region previously considered free of these tapeworms. Because of human and animal health concerns, we estimated the prevalence of infection in wild canids across southern Ontario," reads an excerpt from the study.\nIn a report by the Toronto Star, Professor Andrew Peregrine, who works at Guelph’s Ontario Veterinary College, revealed that one of the infected dogs had been found in the area, making the discovery all the more troublesome to the researchers, who had previously been in the dark about the worm's presence in Ontario.\nAccording to the researchers, humans who become infected by the worm and contract AE tend to feel a variety of symptoms over the course of five to fifteen years. The symptoms include fatigue, abdominal pain, and weight loss.\nBefore developments in modern science, the average survival rate after becoming infected with AE was just 29 percent after 10 years, if left untreated. However, since the invention of chemotherapy, the survival rate has shot up to 80 percent.\nHumans become infected after ingesting the eggs, which are found in their dog's feces, the Star points out. The animal gets the disease by eating an infected rodent. The worm lays its eggs in its stomach, and once the animal passes the eggs through its digestive system, they live in its droppings.\nHumans often contract the disease by picking up their pet's waste and forgetting to wash their hands or even by sleeping in the same bed as their dog who may have feces on its fur. The tapeworms are microscopic and are therefore not visible to the human eye.