My dog has a cold and a fever — what medicine brings the fever down quickly?

A cold and a fever are two separate issues that should be treated together. For the fever, use physical cooling or a dog-specific fever reducer; above 40°C, see a vet for an injection. The cold is a respiratory infection — treat it with a vet-recommended canine cold medicine. Address each symptom separately, and if other illnesses are present, consult a vet before more medication.