As dogs get older, many pet owners begin to notice changes in energy, mobility, appetite, sleep, and behavior. Some slowing down can be a normal part of aging, but other changes may signal pain, arthritis, dental disease, kidney disease, cancer, or another medical problem. Knowing the difference between normal aging and illness can help dog owners seek veterinary care sooner and support a better quality of life. Dr. Roger Hart at Bushnell Animal Clinic explains what to watch for in senior dogs and when slowing down should be taken seriously.