Diabetes Mellitus in Dogs

Insulin resistance caused by obesity, advancing age, certain health conditions (e.g., hyperadrenocorticism, hypothyroidism, hypertriglyceridemia, and pancreatitis), and genetics are associated with increased risk for, or challenges in managing, diabetes mellitus in dogs.^1,2 Neutered males and intact females are also at greater risk of developing diabetes compared to intact male dogs.

The classic clinical signs of canine diabetes mellitus are polyuria, polydipsia, polyphagia, and weight loss. Onset of signs is typically subtle, occurring over weeks to months, and may initially go unnoticed by the dog owner.

The goals of dietary management are to:

• help regulate glycemic control to manage clinical signs of diabetes while avoiding hypoglycemia
• achieve and/or maintain healthy body condition and muscle mass

Key Messages

• In newly diagnosed dogs, the first goal of diabetes management is to reduce and control hyperglycemia through insulin administration and diet. 
  • An important complication associated with insulin therapy is hypoglycemia, or excessively low blood glucose concentration. In dogs, it is defined as blood glucose < 60 mg/dL (< 3.3 mmol/L).⁴
  • Signs of hypoglycemia may occur suddenly and can include: 
    • weakness
    • extreme lethargy
    • muscle twitching
    • trembling
    • incoordination
    • unusual behavior
    • seizures
    • collapse
    • coma
• Nutritional management of diabetic dogs is different from diabetic cats because the underlying disease etiologies are different. 
  • The starch, or digestible carbohydrate, content of complete dog foods is the main determining factor of postprandial glucose and insulin responses in healthy dogs.^5─7 
  • The amount and source of dietary starch can alter postprandial glucose in diabetic dogs.^8,9
  • Increased soluble and insoluble fiber can reduce postprandial hyperglycemia and reduce caloric content.^1,10
• Diet recommendations depend on individual factors such as body condition score, body weight, food acceptance, exercise, and treats. A diet that will correct obesity (if indicated), optimize body condition, and minimize postprandial hyperglycemia is recommended.
  • Dogs with uncomplicated diabetes can do well with a palatable, nutritionally balanced diet that contains a moderate dietary fiber content. The key is to assure consistent intake so that insulin can be coordinated with nutrient absorption.¹
  • Underweight diabetic dogs can benefit from a higher calorie diet containing moderate amounts of both soluble and insoluble fiber.
  • Dietary fat restriction (< 30% of metabolizable energy [ME]) is recommended for diabetic dogs with concurrent chronic pancreatitis or persistent hypertriglyceridemia, except for diabetic dogs in thin body condition.¹¹
• Once glycemic control is established, managed weight loss in obese dogs can help improve sensitivity to insulin. 
  • The target rate of weight loss is 1% to 2% of body weight per week.¹
  • For overweight and obese diabetic dogs needing to lose weight, therapeutic diets for weight management reduce the risk of nutritional deficiencies because they are formulated to be complete and balanced at low caloric intake.¹²
  • Weight loss in obese patients may reduce the amount of insulin needed to maintain healthy blood glucose levels.
• Meals of equal size should be fed twice daily at the time of insulin administration.
• Checking for clinical signs is important to effective diabetes monitoring.
  • At home, dog owners can monitor water intake, urine output, appetite, and body condition.
  • Veterinary healthcare teams will want to monitor muscle mass, body weight, and body condition regularly in all diabetic patients.
  • Rapid and/or unplanned weight loss is an indication of poorly controlled diabetes.
• Adjust dietary recommendations, as needed, when concurrent diseases are present (e.g., pancreatitis, renal disease, or intestinal disease).

1. Behrend, E., Holford, A., Lathan, P., Rucinsky, R., Schulman, R. (2018). 2018 AAHA diabetes management guidelines for dogs and cats. Journal of the American Animal Hospital Association, 54(1), 1─21. doi: 10.5326/JAAHA-MS-6822
2. Heeley, A. M., O’Neill, D. G., Davison, L. J., Church, D. B., Corless, E. K., & Brodbelt, D. C. (2020). Diabetes mellitus in dogs attending UK primary-care practices: Frequency, risk factors and survival. Canine Medicine and Genetics, 7, Article 6. doi: 10.1186/s40575-020-00087-7
3. Davison, L. J. (2015). Diabetes mellitus and pancreatitis—cause or effect? Journal of Small Animal Practice, 56(1), 50─59. doi: 10.1111/jsap.12295
4. Idowu, O., & Heading, K. (2018). Hypoglycemia in dogs: Causes, management, and diagnosis. Canadian Veterinary Journal, 59(6), 642─649.
5. Carciofi, A. C., Takakura, F. S., de-Oliveira, L. D., Teshima, E., Jeremias, J. T., Brunetto, M. A., & Prada, F. (2008). Effects of six carbohydrate sources on dog diet digestibility and post-prandial glucose and insulin response. Journal of Animal Physiology and Animal Nutrition, 92(3), 326─336. doi: 10.1111/j.1439-0396.2007.00794.x
6. Elliott, K. F., Rand, J. S., Fleeman, L. M., Morton, J. M., Litster, A. L., Biourge, V. C., & Markwell, P. J. (2012). A diet lower in digestible carbohydrate results in lower postprandial glucose concentrations compared with a traditional canine diabetes diet and an adult maintenance diet in healthy dogs. Research in Veterinary Science, 93(1), 288─295. doi: 10.1016/j.rvsc.2011.07.032
7. Nguyen, P., Dumon, H., Biourge, V., & Pouteau, E. (1998). Glycemic and insulinemic responses after ingestion of commercial foods in healthy dogs: Influence of food composition. Journal of Nutrition, 128(12 Suppl), 2654S─2658S. doi: 10.1093/jn/128.12.2654S
8. Teixeira, F. A., Machado, D. P., Jeremias, J. T., Queiroz, M. R., Pontieri, C., & Brunetto, M. A. (2020). Starch sources influence lipidaemia of diabetic dogs. BMC Veterinary Research, 16(1), 2. doi: 10.1186/s12917-019-2224-y
9. Teshima, E., Brunetto, M. A., Teixeira, F. A., Gomes, M., Lucas, S., Pereira, G. T., & Carciofi, A. C. (2021). Influence of type of starch and feeding management on glycaemic control in diabetic dogs. Journal of Animal Physiology and Animal Nutrition. Advance online publication. https://doi.org/10.1111/jpn.13556
10. Kimmel, S. E., Michel, K. E., Hess, R. S., & Ward, C. R. (2000). Effects of insoluble and soluble dietary fiber on glycemic control in dogs with naturally occurring insulin-dependent diabetes mellitus. Journal of the American Veterinary Medical Association, 216(7), 1076─1081. doi: 10.2460/javma.2000.216.1076
11. Fleeman, L. M., Rand, J. S., & Markwell, P. J. (2009). Lack of advantage of high-fibre, moderate-carbohydrate diets in dogs with stabilised diabetes. Journal of Small Animal Practice, 50(11), 604─614. doi: 10.1111/j.1748-5827.2009.00817.x
12. Gaylord, L., Remillard, R., & Saker, K. (2018). Risk of nutritional deficiencies for dogs on a weight loss plan. Journal of Small Animal Practice, 59(11), 695–703. doi: 10.1111/jsap.12913