The second dog to test positive in the U.S., in Georgia, and the sixth dog, in South Carolina, have both died, for example, and their deaths were attributed to other conditions.

In a recent study, subjects rated the welfare of dogs, ranging from street dogs and fighting dogs to show dogs and personal pets. Nearly everyone thought their dog had a better life than other ...

Scientists are making headway in pinpointing the cause of the condition reported in more than a dozen states. Here’s what we know so far about the illness—and how to protect your pet.