When it comes to human company, dogs are very similar to people. Some dogs are perfectly happy to be alone when the owner is away, and all they require is to have their physical needs taken care of. Once they have their food and water and have been out for a short walk to relieve themselves, they are perfectly happy to go to sleep and wait for their owner to return.
Being pack animals, the majority of dogs do not like to be alone. Their reaction to loneliness varies from being nervous and inclined to bark more than necessary, all the way to separation anxiety and destructive behaviour. While separation anxiety can be a serious problem and require the help of a trainer, or even a vet to administer calming drugs, the less severe forms of discomfort can easily be alleviated by having a dog caregiver spend time with them.
I have had experience with dogs that need my presence from the moment the owner leaves the house to when the owner returns. To feel at ease, they like to be talked to, played with and petted, or just the presence of a human whom they know and trust. A lot of dogs are far more sensitive than we realize, and good owners know what their dog needs to be calm and happy.
I am always happy to help a dog in need of a loving, reassuring presence.