A dry or warm nose indicates a dog is sick right ?

This is a very widely spread belief, but it’s also false. Both the temperature and humidity of a dog’s nose change frequently throughout the day, regardless of whether the dog is sick or not. These changes are usually related to environmental conditions: poor air circulation, room temperature, etc. You should always rely on abnormal clinical signs, such as not eating, lethargy or vomiting, as indicators of illness, rather that the state of your dog’s nose.