We are not encouraged, on a daily basis, to pay careful attention to the animals we eat. On the contrary, the meat, dairy, and egg industries all actively encourage us to give thought to our own immediate interest (taste, for example, or cheap food) but not to the real suffering involved. They do so by deliberately withholding information and by cynically presenting us with idealized images of happy animals in beautiful landscapes, scenes of bucolic happiness that do not correspond to anything in the real world. The animals involved suffer agony because of our ignorance. The least we owe them is to lessen that ignorance.
Perhaps one central reason for loving dogs is that they take us away from this obsession with ourselves. When our thoughts start to go in circles, and we seem unable to break away, wondering what horrible event the future holds for us, the dog opens a window into the delight of the moment.