A dog's yellow nose may be caused by respiratory inflammation, pneumonia, viral cold, or canine distemper. You need to observe whether the dog has other symptoms. If it is not serious, you can give some cold medicine and anti-inflammatory medicine first; if not, If the pet improves or develops symptoms such as poor energy, loss of appetite, vomiting, diarrhea, blood in the stool, etc., it is best to send it to the pet hospital for examination immediately to confirm the cause and then carry out targeted treatment.