The reason why dogs have tear stains: Diet

An overly salty diet is the most common and common reason for dogs to have tear stains, because some dog owners feed their dogs dog food or homemade dog food that contains The salt content is too high, or it contains grains that are susceptible to allergies, such as cornmeal, wheat, etc. Some even feed dogs rice or fried foods that are eaten by humans. These are very easy to cause dogs to get angry, not only causing the dog's urine to turn yellow, but also easily producing tear stains.
The best solution to this situation is to change the dog's food. It is recommended to use natural dog food containing vegetables or fruits, which will reduce the condition of the dog's tear stains.

The reason why dogs have tear stains: ear canal infection

When a dog’s ears are infected by viruses, such as ear mites, otitis, etc., it will cause swelling and itching of the dog’s ears. Dogs scratch their ears frequently. However, the nerves on the dog's face are intertwined and it is a very sensitive area. When the pain in the dog's ear canal extends to around its eyes, it will stimulate the tear glands to secrete tears. When there are too many tears that cannot be discharged from the nasolacrimal duct, they will flow out from the corners of the eyes. After a long period of accumulation, tear stains are formed.
The best solution to this situation is to clean the dog’s ear canal regularly to avoid ear mite infection.

Causes of tear stains in dogs: eye diseases

A large proportion of dogs have tear stains caused by eye diseases, such as nasolacrimal duct obstruction, dacryoadenitis or entropion of the eyelids. When a normal dog's lacrimal gland secretes tears, they will enter the pet's nasal cavity through the tear duct and will not flow out from the corner of the eye. However, if the nasolacrimal duct is blocked, the tears will flow out from the corner of the eye. Over time, dog tear stains form. There is also the situation where the eyelashes of the dog's eyes are inserted inwards into the eyes. This will cause the eyelashes to irritate the dog's cornea and also cause tear stains.
The best solution to this situation is to take the dog to the hospital for treatment.