There is now convincing evidence that pain can be transmitted socially. Rodents communicate distress and are affected by the distress of others. Pain odor signals may be transferred from one rodent to another by compounds left in the air. Odor may function as a signal that can transmit pain sensitivity from one animal to the next. The spreading of pain seems to spread through the nose. Rodents in pain may give off odor cues that make healthy rodents nearby more sensitive to pain. Rodents can share each other’s heightened sensitivity to pain. Pain can move from one animal to another, no injury or illness is required. Sometimes pain isn’t caused by an injury, instead, social factors or cues; seeing another in pain might affect pain awareness. These findings might help explain why lingering pain may begin peculiarly or just persist long after some injury heals.
https://www.linkedin.com/pulse/rodent-pain-can-infectious-randy-bilesky?published=t