The next day, both Caribou and Fort Fairfield announced their dog parks would be closed indefinitely. A national parvovirus tracker produced by animal health company Elanco displays a high risk of the virus in Maine. The clinic urged those with unvaccinated dogs not to bring them to a dog park or other areas with high canine traffic. The disease spreads more quickly in places where dogs gather, according to the Maine Department of Agriculture, Conservation and Forestry. The department today urged pet owners to keep puppies, unvaccinated dogs or those with compromised immune systems away from dog parks and similar places until they receive immunization.