Dogs are my favorite as one can see from these images. It helps me to have a camera at hand at all times since no one can predict what they will do next. Some days I wonder if they can anticipate their next moves. It is most helpful for me to be using a zoom lens like a 80-200 mm. to catch their action or remove a distracting background from an image. At times I will use a 300 mm. with a teleconverter if I think it will benefit an image.
Patience is always a plus when dealing with pet photography.
My biggest problem has been that they want to approach the camera or will not obey my commands. Unfortunately, all of my labs were very spoiled making any photos very difficult. Be patient 2. Always focus on the eyes. Shoot for action.