Cough syrup can be eaten by dogs, but you need to consult a professional doctor on dosage and usage to avoid side effects caused by overeating. It is best to choose pediatric cough syrup. There are many reasons for dogs to cough. The most common one is a cold. If the condition is serious and accompanied by other symptoms, it may be a respiratory infection. It needs to be sent to the hospital for further examination and confirmation and timely treatment to avoid delaying the condition.