Schnauzers generally don’t shed tears. If they are sad, they will suffer from depression, loss of appetite, inactivity, etc. Generally, it can be directly seen that a dog is unhappy, so as long as you carefully observe the dog’s expression, You can understand your dog’s mood. If your Schnauzer sheds tears, it may be caused by eye disease or eye discomfort. You need to check whether there are foreign objects in the dog's eyes.