Hypoglycemia (Low Blood Sugar) in Dogs

What is hypoglycemia

Hypoglycemia is a health condition characterized by a critically low blood sugar levels. Since glucose or blood sugar is the main source of energy, its deprivation causes a decline in organ functions, which may lead to loss of consciousness and even death. Hypoglycemia is not considered a disease, but an indicator of an underlying health problem ^{[1, 2]}.

What causes hypoglycemia in dogs

Though the exact causes are not known, according to scientific studies, hypoglycemia may be associated with:

• Sudden over-metabolization of glucose
• Liver or hormonal disorders
• Overdosing on insulin in dogs with diabetes ^[4]
• Intake of harmful substances such as xylitol found in artificial sweeteners
• Ingestion of beta-blocker medication used for treating irregular heartbeat
• Decreased glucose production due to starvation, malnutrition, or long interval between meals ^{[3, 4]}

Risk factors

• Gastrointestinal or liver cancer
• Glycogen-storage disease
• Liver inflammation
• Liver shunt
• Tumor in pancreas (insulinomas) ^[3]

Which dog breeds are more likely to get it

• Hunting or working dogs, because they burn a lot of energy during strenuous works and exercise ^[1].
• Small breeds, since they require more blood glucose owing to their high energy requirement per unit of body weight. It occurs because they have a high ratio of body surface area to weight ^{[1, 7]}.
• Puppies under the age of 3 months, as they are not able to keep their blood sugar levels within the acceptable range, possibly due to cold weather, improper feeding, parasite infections, over exercise, etc ^[1].

Signs and symptoms of hypoglycemia in dogs

Hypoglycemia symptoms are not always persistent, often occurring suddenly. Take your dog to the vet as soon as possible if you see any of the following symptoms:

• Lethargy ^[4]
• Vision impairment ^[1]
• Muscle twitching ^[6]
• Lack of coordination ^[6]
• Disorientation – inability to perform routine tasks ^[1]
• Nervousness, anxiety, restlessness ^[1]
• Trembling ^[1]
• Seizures ^[1]
• Increased thirst and appetite ^{[1, 5]}
• Palpitations ^[1]
• Loss of consciousness ^{[5, 6]}

Prevention

• Providing your dog with a nutritious diet including protein-rich foods like chicken, fish, and eggs can help in maintaining a normal blood glucose level.
• Testing for hypoglycemia after fasting, for example before surgery, can help in early detection of the condition ^[6].

Diagnosis

If your vet suspects hypoglycemia after reviewing your dog’s clinical symptoms and medical history, a detailed physical exam is performed. An initial measurement of blood sugar level using a glucometer is taken. A reading lower than the normal range, i.e., 3.3-6.1 mmol/L, suggests hypoglycemia ^{[3, 6, 8]}.

To assess the health and functioning of various organs and detect other blood-related conditions, the following tests may be done:

• Blood tests like a CBC, thyroid test, cortisol test, and electrolyte test to check for any other complication present ^{[3, 9]}
• Chemistry blood tests to assess the functions of pancreas, liver, and kidney ^[3]
• Urinalysis to investigate the presence of infection in the urinary tract ^[9]

If the underlying cause of hypoglycemia is believed to be associated with tumor or cancer in the pancreas, a transabdominal ultrasound may be done ^{[3, 9]}.

Treatment for hypoglycemia in dogs

Once your dog is positively diagnosed with hypoglycemia, you should consult your vet about some emergency treatment measures.

If glucose levels drop suddenly and your dog exhibits severe symptoms, it might help to rub some fruit juice, Karo syrup, honey, or sugar on its gums. In case of severe symptoms, immediately take your pet to the vet. Once the dog is stable, it may be given small meals as the condition improves. In case it is too sick to even eat, intravenous fluids with concentrated dextrose may be administered ^{[3, 5]}.

If the initial treatment measures fail to manage the blood glucose levels, seizures may occur. Anticonvulsant medications like diazepam may be prescribed for controlling seizures ^[5].

To prevent recurrent hypoglycemic episodes, the underlying cause has to be identified and treated. While endocrine diseases are treated with medications, toxicity is controlled by supportive treatment like oxygen, rest, intravenous fluids, supplements, and medications. If a portosystemic shunt, tumor, or pancreatic cancer is its causative factor, surgical management may be necessary ^[3].

Follow-up treatment and home monitoring

Once a hypoglycemic dog is discharged after treatment or surgery, the vet usually recommends certain follow-up measures, including:

• Limiting physical activity in highly active dogs, small breeds, and puppies to keep symptoms from recurring.
• Providing puppies with small meals several times a day, while feeding active dogs a few hours before any heavy activity ^[3].

Prognosis

The expected recovery time is variable, depending upon the underlying conditions and whether those can be managed or cured. However, if left untreated, these symptoms may progress, along with the underlying disorders, even leading to a life-threatening condition ^[1].