Dogs can eat phlegm-reducing syrup, but it is best to eat children's phlegm-reducing syrup. This way, it is easier to control the dosage and avoid side effects caused by excessive dosage. Moreover, the sugar content in the syrup is relatively high, so feed it to your dog as little as possible. When a dog has symptoms of coughing, it is necessary to determine the cause. If it is caused by a cold, you can take cold medicine. If it is caused by other diseases, you need to go to the hospital for examination and treatment.