Authorities in Stoughton, Massachusetts, issued a warning to residents on Friday after a dog died after swimming in a local pond. Stoughton’s Health Board reported in a press release issued on Friday that it regretted the news of the death of a dog who had swam in Ames Pond this week. They also indicated that both the Health Board and environmental health agents are investigating the matter. “We inform them that the water on Ames Pond beach is a…