Pathogenesis

Read More About Canine Diabetes

Pathogenesis of Canine Diabetes Mellitus

Diabetes mellitus is a paradox: simultaneous extracellular hyperglycemia and intracellular glucose deficiency. The consequences of insulin deficiency or receptor insensitivity are reduced peripheral tissue utilization of glucose, amino acids, and fatty acids. This results in the accumulation of glucose in the blood (hyperglycemia). Glucose is a small molecule and is freely filtered through the glomerulus in the kidney. In normal dogs, the renal tubules will reabsorb the filtered glucose.

However, if the blood glucose rises above the renal threshold (approximately 180 mg/dL [10 mmol/L]), these tubular reabsorption mechanisms are overwhelmed, and glucose appears in the urine. Glucose exerts an osmotic diuretic effect that leads to polyuria. To compensate, water consumption increases (polydipsia). Dogs with diabetes tend to lose weight due to caloric loss with glucosuria and reduced peripheral tissue anabolism. Despite hyperglycemia, there is hypothalamic intracellular hypoglycemia that results in the stimulation of the hunger center and polyphagia. The consequences of this paradox are reflected in Figures 1 and 2.

Figure 1

Figure 2

Untreated or unrecognized diabetes mellitus may progress to diabetic ketoacidosis. In the absence of sufficient insulin, dogs with diabetes will switch from glucose to fat metabolism for cellular energy. While fats are initially beneficial energy sources, lipid waste products (ketone bodies) accumulate in the blood and invoke severe and potentially life-threatening metabolic abnormalities.

Dogs with ketoacidotic diabetes can present with severe clinical signs (severe depression, anorexia, vomiting, dyspnea, collapse, or coma). Clients may not have recognized or reported that the classic clinical signs of diabetes were present. Without aggressive and determined management, dogs with ketoacidosis may die.

Help Your Practice Manage Diabetes Mellitus

View and download resources and tools that will assist your hospital, inform your team, and help with clients.

Read More About Canine Diabetes

Important Safety Information:

Vetsulin^® should not be used in dogs known to have a systemic allergy to pork or pork products. Vetsulin is contraindicated during periods of hypoglycemia. Keep out of reach of children. As with all insulin products, careful patient monitoring for hypoglycemia and hyperglycemia is essential to attain and maintain adequate glycemic control and prevent associated complications. Overdosage can result in profound hypoglycemia and death. The safety and effectiveness of Vetsulin in puppies, breeding, pregnant, and lactating dogs has not been evaluated. See package insert for full information regarding contraindications, warnings, and precautions.

References:

1. Martin GJ, Rand JS. Pharmacology of a 40 IU/ml porcine lente insulin preparation in diabetic cats: findings during the first week and after 5 or 9 weeks of therapy. J Feline Med Surg. 2001;3(1):23–30. 2. Vetsulin^® (porcine insulin zinc suspension) [Freedom of Information Summary]. Millsboro, DE: Intervet Inc.; 2008. 3. Data on file, Merck Animal Health. 4. Graham PA, Nash AS, McKellar QA. Pharmacokinetics of porcine insulin zinc suspension in diabetic dogs. J Small Anim Pract. 1997;38(10):434–438. 5. Martin GJ, Rand JS. Pharmacokinetic and Pharmacodynamic Study of Caninsulin in Cats with Diabetes Mellitus. 2000: Internal Study Report. 6. Feldman EC, Nelson RW. Canine and Feline Endocrinology and Reproduction. 3rd ed. St. Louis, MO: Saunders; 2004:539–579. 7. Tennant B, ed. BSAVA Small Animal Formulary. 4th ed. Gloucestershire, UK: British Small Animal Veterinary Association; 2002. 8. Feldman EC, Nelson RW. Canine and Feline Endocrinology and Reproduction. 3rd ed. St. Louis, MO: Saunders; 2004:486–538. 9. Reusch C. Feline diabetes mellitus. In: Ettinger SJ, Feldman EC, eds. Textbook of Veterinary Internal Medicine. 7th ed. St. Louis, MO: Saunders; 2010:1796–1816. 10. Nelson RW. Canine diabetes mellitus. In: Ettinger SJ, Feldman EC, eds. Textbook of Veterinary Internal Medicine. 7th ed. St. Louis, MO: Saunders; 2010:1782–1796. 11. Burgaud S, Riant S, Piau N. Comparative laboratory evaluation of dose delivery using a veterinary insulin pen. In: Proceedings of the WSAVA/FECAVA/BSAVA congress; 12–15 April 2012; Birmingham, UK. Abstract 121. 12. Burgaud S, Guillot R, Harnois-Milon G. Clinical evaluation of a veterinary insulin pen in diabetic dogs. In: Proceedings of the WSAVA/ FECAVA/BSAVA congress; 12–15 April 2012; Birmingham, UK. Abstract 122. 13. Burgaud S, Guillot R, Harnois-Milon G. Clinical evaluation of a veterinary insulin pen in diabetic cats. In: Proceedings of the WSAVA/FECAVA/BSAVA congress; 12–15 April 2012; Birmingham, UK. Abstract 45. 14. Davison LJ, Walding B, Herrtage ME, Catchpole B. Anti-insulin antibodies in diabetic dogs before and after treatment with different insulin preparations. J Vet Intern Med. 2008;22:1317-1325. 15. Banfield State of Pet Health 2016 Report. p 12-13.