Why does my dog need insulin injections, and will it be a long-term treatment?
Diabetes mellitus (DM) is a complex but treatable disease in dogs. Genetic and breed factors predispose some dogs to DM, and some lifestyle issues can contribute. DM is a disease in which the body can no longer appropriately manage how it uses glucose (from food) to meet energy requirements.
Glucose management involves the pancreas - an organ that sits near the stomach and small intestine and helps with food digestion and glucose regulation.
When blood glucose levels increase (e.g., after a meal), the pancreas secretes a hormone called insulin, which helps move glucose from the blood into the cells, especially muscle, heart, and fat cells. In dogs with DM, the pancreas doesn’t make enough insulin and so an external source (from outside the animal’s body) must be given every day.
If a dog with DM doesn’t receive insulin, they will experience high blood sugar levels (hyperglycemia), which can become life-threatening if ignored or untreated. Therefore, insulin therapy is required for the rest of the dog’s life, but with consistent care and regular monitoring, these dogs can live a full and healthy life.
What lifestyle issues contribute to DM?
The most important lifestyle factor that contributes to the development of DM in dogs is being overweight or obese. Not all the influences of obesity on DM are well understood, but we know that obese dogs tend to eat more, which results in increased secretion of insulin from the pancreas.
Excess body fat may also create a condition called insulin resistance, in which the cells don’t respond normally to insulin. This abnormal response causes persistently higher levels of glucose in the blood, which triggers the pancreas to secrete even more insulin. Some fat stores (or adipose tissue) may secrete hormones that are inflammatory and pro-inflammatory, and these hormones can further stress the pancreas and other organs.
Ultimately, the best way to deal with DM is to do everything possible to prevent it. Obesity prevention involves direct control of food portions when feeding a dog, and it’s recommended to start when dogs are still puppies. Puppies that are allowed to grow too quickly develop more fat cells than puppies that are portion-fed and allowed to grow more slowly. Juvenile obesity stresses the body's tissues, bones, and joints, and increases the risk of various diseases (like DM) later in life.
How can I help my dog now that they have diabetes?
Once a dog has been diagnosed with DM, insulin injections are essential. After that, the most important long-term management strategy is achieving or maintaining a lean body condition. A lean body condition allows better control of blood sugar, which is critical for managing DM. It is important to work closely with your family veterinarian throughout the process, as they will use their knowledge and experience to choose the best insulin source for your dog and the most appropriate nutrient profile to normalize weight.
"Once a dog has been diagnosed with DM, insulin injections are essential."
During weight loss, the goals are to maintain blood glucose levels close to the normal range and to preserve muscle, while utilizing fat selectively as an energy source. There is good scientific data to guide nutritional choices, and your veterinarian is your best partner in making decisions about which diet to feed, how much, and how often. A higher percentage of lean body mass contributes to less insulin resistance in the tissues, and this can lead to the need for a lower insulin dose.
Dogs with a more normal body mass and better body composition tend to feel better and often want to be more active. Regular movement or daily activity can help the body use its energy more effectively. For dogs in lean body condition, daily activity may be walking, running, and playing with other pets or toys between 40 and 140 minutes. For dogs who are overweight or obese, daily activity may be more challenging, but a reasonable goal is to slowly work up from 5–10 minutes to 30–60 minutes per day.
Physical rehabilitation can also be used as a mode of therapy and structured support in weight loss programs and pain management programs. Its use in veterinary medicine has grown in the past two decades. Rehabilitation services have trained technicians and veterinarians who can offer in-house programs as well as exercises that can be done at-home.
Will I need to change how I feed my dog?
Insulin therapy for DM requires dogs to eat at or near the time of an insulin injection. Giving insulin without a meal can cause the pet’s blood sugar levels to drop too low – a condition called hypoglycemia that can cause life-threatening illness. Most veterinarians recommend giving the insulin injection just as the dog finishes a meal to link the injection to something desirable (food), and to ensure the dog has taken in the appropriate amount of calories.
If your dog does not eat, for any reason, do not give insulin (unless directed to give a different dose by your veterinarian). If you have a home glucose monitoring device, take a blood glucose reading. A missed meal may mean hypoglycemia. Once you know the blood glucose level, call your veterinarian for guidance. If you do not have a home monitoring device, skip insulin and call your veterinarian as soon as you can.
Can I stop giving my dog insulin if I feed him as my veterinarian recommends?
Once a dog is diagnosed with DM, it is not realistic to expect that insulin injections can stop. The best case scenario for dogs with DM is good control of blood glucose levels (referred to as glycemic control). It is important to pay attention to the dog’s nutrient profile, such as protein content, fat content, and sources of insoluble dietary fiber, as these factors play a role in achieving glycemic control in dogs with DM.
"Once a dog is diagnosed with DM, it is not realistic to expect that insulin injections can stop."
Several veterinary therapeutic foods have been developed to facilitate glycemic control. Your family veterinarian can recommend an appropriate formulation, calculate the daily caloric goal, and give guidance on exact proportions to feed at each meal, based on their clinical experience managing other patients with DM.
Will my diabetic dog have to eat a therapeutic food forever?
Once a dog with DM has stable blood glucose levels and is close to an ideal body weight and body condition score, it is critical to maintain as much consistency as possible, which means feeding the recommended food at the prescribed times, giving insulin therapy, and maintaining regular (daily) activity.
Your veterinary health care team plays a valuable role in helping you manage and maintain consistency, through periodic check-ups that include a physical exam, body weight, body condition score, glucose assessment, and other testing and a thorough diet history. If your dog’s glucose levels change, or their insulin requirement needs adjustment, or your dog develops a new medical issue, your veterinarian will want to perform an examination and may require additional diagnostic testing.
They may also recommend a change to either the diet or daily meal portions. One example would be if a diabetic dog developed chronic pancreatitis; in this situation, many veterinarians recommend ultra-low-fat diets. Ultimately, feeding plans must be individualized for the unique circumstances of the pet and the pet parent.
Managing DM in dogs is a complex process that can be frustrating, but many pet owners can support their diabetic dog with guidance and coaching from their veterinary health care team. Nutrition and feeding management, particularly portion control of daily calories to maintain an ideal body weight and increasing daily activity, are key factors that contribute to achieving good glycemic control.
