This may help you with your project.
It all depends on how well the pet owner keeps up with the care and treatment.
I had a cat who lived for years with diabetes, she had a severe case and had to have insulin injections every eight hours but many dogs and cats can be controlled either by pills or just insulin every 12 hours. It was only at 16 1/2 years old she became blind as a result of the diabetes and I didn't know it then but we could have had eye surgery to correct that.
If your dog or cat has been diagnosed with diabetes then with veterinary care their quality of life can be every bit as good as a normal pet.
“Obesity is the number one health problem affecting dogs and cats,” reports The Globe and Mail of Canada. “The causes are similar in humans and animals: Poor eating habits and lack of exercise.” The Canadian Veterinary Medical Association council, blames the life-style of pet owners: “We don’t get enough exercise because we’re rushed. The dog doesn’t get enough exercise because the owner is rushed. We need comfort food so our pets get comfort food.” The Globe warns that “overweight pets have a higher risk of diabetes, heart disease, high blood pressure and arthritis. . . . They die younger than healthy animals.” Veterinary treatment for obese pets usually includes a restricted diet and, for dogs, increased exercise.