Signs of Low Blood Sugar in Dogs

Veterinarians diagnose low blood sugar--called hypoglycemia--in a dog when the animal's blood glucose levels drop below the optimal range of 100 to 180 milligrams per deciliter (mg/dl). The animal's body uses glucose as the primary source of nourishment and energy. Young puppies, nursing or pregnant mothers, toy breeds less than three months of age, and diabetic dogs who accidentally receive too much insulin can develop hypoglycemia. The disease also occurs in adult dogs with hormonal imbalances, such as hyperthyroidism and Addison's disease. Signs and symptoms typically begin once glucose concentrations reach around 70 to 80 mg/dl. If this happens, you need to seek immediate veterinary attention to stop the disease from quickly progressing.

  1. Mild Disease Stage

    • Dogs in the initial stages of hypoglycemia suffer from extreme lethargy and a lack of energy because of the shortage of energy-producing sugars in the body. Shivering and trembling often follows the sluggishness, as the body attempts to heat itself and avoid going into shock. Your dog may show signs of a sudden, ravenous hunger to replenish its energy stores, or begin to refuse food due to nausea.

    Moderate Disease Stage

    • As your dog's glucose levels continue to drop, its pupils may become dilated and it may have trouble with its vision, appearing suddenly blind. Hypoglycemic dogs often have difficulty moving, show poor coordination and may begin to stagger and walk in circles. Your dog can become disoriented and restless (acting "drunk"), and demonstrate strange head and neck movements. Some affected animals begin urgently barking due to anxiety.

    Severe Disease Stage

    • If left untreated, uncontrolled hypoglycemia causes animals to convulse and "seize" due to lack of glucose in the brain. Your dog may lapse into a coma and begin to have difficulty breathing. Lowered heart rate and organ failure will lead to death without immediate veterinary intervention.