Emergency Complications of Diabetes Mellitus
By Dr. Laura Higgins
Diabetes mellitus is a relatively common disorder in both dogs and cats. The disease is characterized by persistently elevated blood sugar secondary to either low insulin levels or insulin resistance. Both cats and dogs have an excellent prognosis for a good quality of life when treated and monitored appropriately. This article will focus only on the emergency situations that may arise secondary to diabetes, including hypoglycemic crises, diabetic ketoacidosis (DKA), and hyperglycemic hyperosmolar syndrome (HHS).
Hypoglycemic crisis refers to dangerously low blood sugar levels. Patients may experience weakness, disorientation, and/or seizures. Cats are more commonly affected than dogs. An error during insulin administration may be responsible for severe hypoglycemia. Some cats are transient diabetics, meaning at times their own insulin functions normally. These cats may abruptly no longer require additional insulin, resulting in a hypo-glycemic crisis that would have been unforeseen by their family or veterinarian. Treatment of a hypoglycemic crisis includes blood sugar stabilization and control of neurologic symptoms. In-hospital stabilization is done with intravenous dextrose (a blood sugar) and monitoring. These patients require minimally 12 hours of dextrose. Once stable, the patient can be restarted on insulin therapy, although future dosing may need to be adjusted.
DKA is characterized by an overproduction of ketones, an acid that builds up when the body is unable to effectively use blood sugars. This is can be a problem of both Type I and Type II diabetics. In 70% of dogs and 90% of cats, stress and concurrent illness is a factor that results in the patient’s inability to regulate their blood sugar. This syndrome is frequently the pet’s first manifestation of diabetes. Typical complaints for patients experiencing DKA include increased urination, increased drinking, loss of energy, appetite loss, and vomiting. Treatment of underlying disease and fluid therapy are the foundation of treatment, as well as management of electrolyte and pH imbalances. With treatment, it is reported that 70% of dogs and cats with DKA survived.
The final diabetes-related syndrome we sometimes see in the emergency room is hyperglycemic hyperosmolar syndrome, or HHS. This syndrome is characterized by exorbitantly high blood sugar levels. This results in a fluid imbalance in the brain which triggers seizures, extreme weakness, and/or coma. Like patients with DKA, development of HSS is likely secondary to other illness. Treatment of HSS is similar to DKA with the primary goals being fluid and electrolyte correction, as well as slowly decreasing the blood sugar levels. The major difference with this particular syndrome is that the prognosis is poor; the mortality rate for cats in one study was 65%, and only 12% survival after 2 months.
By recognizing the signs of a serious complication and seeking immediate veterinary advice, hypoglycemic crises and diabetic ketoacidosis may be treated and resolved. The prognosis for hyperglycemic hyperosmolar syndrome however is considerably worse. Nevertheless, with treatment and regular monitoring most diabetic patients will lead long, happy lives.
AMVS is a 24-hour veterinary facility providing specialty internal medicine, surgery, emergency and critical care, physical rehabilitation, pain management, and blood bank services for pets. They are located in Longmont at 104 S. Main St. For more information, go to www.AspenMeadowVet.com.