Diabetes mellitus (DM) is a common endocrine disease in dogs. This disease results from a lack of the hormone insulin. Diabetes mellitus results from a change in cellular transport and metabolism of glucose, fats and amino acids where the insulin-dependent tissues (e.g., skeletal and cardiac muscle, adipose tissue) either never receive the signal or fail to properly understand the signal. 

With diabetes, the glucose-insulin connection doesn’t work as it should. In the dog, loss of beta cells is rapid and progressive, and is usually due to immune-mediated destruction, vacuolar degeneration, or pancreatitis. It is a condition that affects the amount of glucose, in your dog's blood. Every time a dog eats, carbohydrates in the food are converted into several types of simple sugars, including glucose. Glucose is absorbed from the intestines into the blood, where it travels to cells and tissues throughout the body. Insulin is needed for the transfer of glucose from the blood into the cells, so that it can be used for energy. If there's too little insulin, glucose cannot enter the cells, which leads to build up in the bloodstream to high concentration. This is known as hyperglycemia. This results in less energy for the cells to function properly and they become starved. Over time, weight loss starts despite a normal or high appetite. The build-up of glucose in the blood gets excreted through the urine and draws large volumes of water, leading to increased thirst and urination. 

Risk factors for onset of Diabetes in dogs include insulin resistance caused by obesity, hyperadrenocorticism, hypertriglyceridemia, and hypothyroidism; dental disease, systemic infection, pancreatitis, pregnancy, or medications (like steroids, progestins, cyclosporine). Genetics is also a risk factor, and certain breeds of dogs (Australian terriers, Beagles, Samoyeds) are more susceptible.  

Symptoms/Signs of Diabetes in Dogs:

  • Polydipsia (excessive thirst)
  • Polyphagia (excessive hunger or increased appetite)
  • Weight loss, in spite of increased appetite
  • Cloudy eyes and impaired vision
  • Reduced activity/lethargy/weakness
  • Chronic infections (skin/urinary)
  • Lackluster coat
  • Vomiting & poor appetite in case of Diabetic Ketoacidosis
  • Muscle weakness
Diagnosis of Diabetes in dogs:

Clinical signs of Diabetes will usually be present when there is hyperglycemia and glucosuria. Your Vet will first test your dog for the presence of glucose and ketones in the urine. The next step typically is to measure your dog’s blood glucose. The diagnosis only becomes definitive when glucose is found both in the urine and at a high level in the blood. Blood Test – Measuring the glucose level in your dog's blood is the most accurate method. Urine Test – This test checks your dog's urine for the presence of glucose and ketones (a chemical produced when the body burns fat for energy).

Other commonly identified abnormalities include increased serum concentrations of cholesterol and triglycerides. Increased serum concentrations of urea nitrogen and creatinine can be present when dehydration becomes severe enough to impair renal diffusion. Comorbidities such as concurrent exocrine pancreatic insufficiency or pancreatitis can also be present in dogs with diabetes. Both hypothyroidism and hyperthyroidism can be associated with insulin resistance and occur in combination with diabetes in dogs.

Management through Diet:

Although diabetes is not a completely reversible disease, it can be managed effectively with proper treatment, diet and exercise. The goal of managing diabetes is to maintain glucose in an acceptable range while avoiding low blood sugar or its related signs. Proper management can reduce or eliminate signs of diabetes, such as excessive thirst and urination and even lethargy. Diet plays an important role in helping keep your dog's diabetes regulated. 

  • In order to avoid changes in insulin levels, keep meal quantity & content same each day. Feed ingredients that have high quality sources of protein, and low carbohydrates. Switch to a reduced-calorie diet if your dog is overweight. 
  • Digestible and complex carbs (oats, millets) should be fed, instead of carbs that spike blood glucose values or are rich in starch. Diabetic dogs have an increased loss of amino acids in urine, which makes feeding high quality animal meat protein sources a must (such as poultry, eggs, red meat etc). Vegetarian protein sources such as paneer, lentils can also be fed in moderation. (However, dogs with renal failure should be fed a low protein diet)
  • Feeding high-fat food may cause insulin resistance and promote hepatic glucose production, and predispose your dog to pancreatitis. Keep the fat intake low, and feed only good quality omega-3 fatty acids (fish/fish oil)
  • Food containing increased fiber can lead to glycemic control of diabetes in dogs. Viscous soluble fibers such as oats, beans, carrot, lentils, flaxseeds, psyllium husk etc are more beneficial than insoluble fibers found in some vegetables, peas, seeds etc
  • Minerals & Vitamins such as chromium, manganese, Vitamin D3 and Vitamin B are essential for normal insulin function. Food sources - animal liver, eggs, fishes, red meat, oats, brown rice etc
  • Feeding foods containing appropriate amounts of electrolytes is important to achieve and maintain normal homeostasis in diabetic dogs. (Food sources – Curd/plain buttermilk, Chicken, Turkey, Bananas, Broccoli, Potatoes, Coconut water, Pumpkin seeds, Watermelon). Fruits should be fed in significant moderation.  
Management through care

Diabetes mellitus is a complex disease. Managing diabetes and controlling hyperglycemia can be challenging. It requires lifelong treatment and care. 
  • Metabolic disruptions due to lack of insulin is common leading to weight loss in dogs. Evaluating an appropriate caloric requirement and feeding the right food is essential in maintaining weight and preventing malnourishment. 
  • Consistent feeding schedule and the amount and timing of exercise should be consistent from day to day to avoid unpredictable changes in blood glucose which may result in potentially severe decreased blood glucose. 
  • Diabetes can lead to rapid depletion in some Vitamins & Minerals in your dog’s body. And so, feeding the right & necessary supplements or whole food sources of these nutrients is a must.
  • A dog diagnosed with diabetes should be evaluated for comorbidities such as Hypo/Hyper Thyroidism, Pancreatitis, Hyperadrenocorticism, Dental disease, Musculoskeletal disorders etc
The good news is that the life expectancy of diabetic dogs that have regulated insulin is similar to other healthy dogs. The best way to properly manage a dog’s diabetes is by feeding a well-formulated home cooked diet, keeping up with regular visits to your Vet, and engaging your dog in consistent & moderate physical activities.