Canine distemper is a highly contagious viral disease that affects dogs and some other animals, such as ferrets and raccoons. It is caused by the canine distemper virus (CDV), which attacks the respiratory, gastrointestinal, and nervous systems. Symptoms can include fever, coughing, vomiting, diarrhea, and seizures. The virus spreads through direct contact with an infected animal or through contaminated surfaces. Vaccination is the most effective way to prevent canine distemper, and it is typically included in routine puppy vaccinations. Early detection and supportive care can improve the chances of recovery for affected dogs.