A dog can improve your mood by reducing stress.  Playing with a dog  and a wagging tail is a way to relieve the stress of looking at a computer monitor for hours each day.

Dogs make excellent watch dogs.  If a potential intruder hears a dog bark they are more likely to move to the next house that does not have a dog.  It is the human principal of least resistance.

Dogs are a diversion for the kids at home.  Now with the kids home watching the computer a dog can act as a diversion to help relieve the tedium of online learning.

Dogs increase social interaction. The covid pandemic has required us to stay at home for many hours.  Getting out and walking the dog and greeting at a socially acceptable distance gives the owner and the dog that chance to interact.

Dogs can increase the master's exercise and health.  With the gyms and other exercise facilities closed down, walking or running with a dog is often our only safe exercise.

Dogs also give you responsibility patients, selflessness and commitment to your animal which in turn should improve both your physical and mental health.

CAUTION:  You must be careful and get the right dog for you.  Dogs have many personalities and it is important to get one that will complement yours.  Also not all persons are dog persons.  You get a cat, which requires less commitment, but can also give you love and affection.  If that doesn't work then get a plant.  For your mental  and physical health it is important to get an outside interest other than that computer.