Mysterious Dog Illness 2024. When a mysterious young couple shows up at their door, their romantic getaway devolves into a twisted psychosexual nightmare. A mysterious canine illness is spreading throughout the country that can linger for months, cause fever, pneumonia and, in rare cases, death.

Signs that warrant a visit to the veterinarian include a lingering cough, weakness, loss of appetite, difficulty breathing, worsening of illness, and a cough that is. Last year and can lead to serious or fatal respiratory problems is still under investigation, but cases are.