Your dog might not tell you they’re feeling lonely, but there will be signs. Agitation doesn’t necessarily mean your dog is lonely, but it’s a good starting point to determine if something might be wrong. Signs your dog might be lonely (or has some other unmet need) can include:Destructive behaviorThink “ripping through the closet and grabbing shoes,” Dr. Schwartz says. Going wild every time another dog comes aroundThis one is a particularly solid clue, according to Dr. Schwartz. If you do want another dog, Dr. Stollar says it could potentially help a lonely pup — under the right conditions.