Answer is as follows
I don’t know what topics you were given but I think the biggest issue is pets being overweight.
I think the cause is over feeding, lack of exercise, and too much people food causes pets to be overweight.
Prevention would be to educate pet owners how to read the pet food packages for size of dog and how much food that size dog should eat per day. Each dog food has a different calorie count per cup of food! Also advise pet owners that people food is not made specifically for a dogs nutritional needs. Lack of exercise causes a pet to be overweight AND unhappy. Owners and pets would both benefit from exercise.