Hypoglycemia in Dogs

Hypoglycemia refers to an abnormal decrease of glucose concentration in the blood, or more simply - low blood sugar levels.  A normal blood glucose value for healthy, non-diabetic dogs is 3.3-6.1 mmol/L.  Hypoglycemia occurs when excessive glucose consumption depletes the reserves of glucose in the body.  Hypoglycemia can be a result of endocrine or hepatic disorders, a higher energy requirement for glucose, lack of glucose due to fasting, or toxicity.  Hypoglycemia will leave dogs feeling weak and groggy.  If left untreated, unconsciousness followed by death may result.

Hypoglycemia is defined as a low blood sugar concentration.  As sugar (in the form of glucose) is the primary energy source in the body, low blood sugar levels will ultimately affect organ and brain function.

Symptoms of hypoglycemia will usually begin with low energy and a delayed response time, if left to progress further these symptoms will develop into more serious signs such as seizures and collapse.  Potential symptoms include:

• Loss of appetite
• Lethargy (low energy)
• Slow response time
• Unusual behaviour
• Polyuria (increased urination)
• Polydipsia (increased thirst)
• Lack of coordination
• Partial paralysis of hindquarters
• Weakness
• Exercise intolerance
• Trembling
• Involuntary twitching
• Seizures
• Unconsciousness

Hypoglycemia can be the result of underlying endocrine or hepatic disorders, sudden increase in the use of glucose by the body, inadequate amounts of glucose, or toxicity.  Causes include:

•  Abnormal growth of pancreatic cells
• Cancer in the liver or gastrointestinal system
• Inflammation of the liver
• Portosystemic shunt
• Glycogen-storage disease
• Excessive strenuous exercise
• Overuse of glucose in the body during pregnancy
• Reduced intake of glucose due to starvation or malnutrition
• Delayed time between meals in kittens and puppies (especially toy breeds)
• Overdosing of insulin
• Toxicity from ingestion of artificial sweeteners

When hypoglycemia is suspected on the basis of the above clinical signs and history, the veterinarian will first perform a complete physical exam.  This will be followed by a measurement of the current blood glucose value and potential ancillary tests to define the underlying causes of the condition. 

The initial blood glucose measurement is assessed using a glucometer (also called a glucose meter) and it is a quick easy test that only requires a small drop of blood from the patient.  This is beneficial for hypoglycaemic puppies and kittens as a large sample is not required. The result appears within a few seconds.  An ideal blood glucose value is 3.3-6.1 mmol/L, any reading that is lower than this indicates hypoglycaemia. 

Additional blood tests may be performed to evaluate organ function (specifically the kidney, liver, and pancreas), electrolyte imbalances, thyroid function, cortisol function, and other blood related conditions.  A urinalysis (urine test) may be performed to eliminate urinary infections or disease, as well as evaluate kidney function.

If the cause of hypoglycaemia is suspected to be related to cancer or tumour growth, then an ultrasound may be performed.

Initial treatment is aimed at correcting the hypoglycemic crisis by way of raising the blood sugar levels.  Depending on the severity and symptoms, this may be initially managed by rubbing glucose or corn syrup on the gums (a treatment which can be started by the owner at home).  If more aggressive therapy is required, the dog will be placed on a intravenous fluid infusion containing concentrated dextrose. Blood glucose levels will be reassessed after the initial treatment.

Ongoing treatment will focus on management of the underlying cause of disease.  If the hypoglycaemia has occurred due to fasting or over exercise, the condition will be resolved after a period of rest.  Dogs will usually be monitored for several hours at the veterinary hospital and then sent home with preventative discharge instructions.

If hypoglycaemia occurred due to a cancer, tumour, or portosystemic shunt then surgery could be necessary.  Inflammatory or endocrine disorders may be treated with medical management.  Toxicity is usually managed with supportive treatment.  Defining and treating the underlying cause is essential or hypoglycaemia will reoccur.

Once a patient is discharged after a hypoglycemic episode, it is important to continue home monitoring for signs of reoccurrence.  Dogs may be sent home with specific surgical discharge instructions or medications to treat the underlying conditions depending on what is performed in clinic.

Special care should be taken in small breed puppies or kittens and highly active dogs to prevent reoccurrence.  For puppies and kittens, frequency of feeding should be increased to several small meals per day instead of one large meal.  For active dogs, it is advised to feed a moderate meal several hours before activity and to keep snacks readily available.  Care should also be taken to monitor dogs closely when there is a requirement for fasting, for example pre-operative periods.

Ultimately, prognosis and the expected time to a full recovery is dependent on the underlying conditions that have contributed to hypoglycemia.

Treatment cost will vary greatly depending on the underlying conditions responsible for the hypoglycemic episode.  For an initial consultation, blood glucose test, and treatment with glucose syrup, the cost will be approximately $80 - $200.  If an intravenous glucose infusion is required this can add an additional $100 - $300.  Treatment cost for underlying causes is based on whether surgical intervention or medical therapy is necessary, and will start from $800.  Ongoing treatment may be necessary and the total treatment cost can be between $1000 - $8000.

Hypoglycemia can be expensive to treat. To avoid high vet care expenses, secure pet health insurance today. The sooner you insure your pet, the more protection you’ll have from unexpected vet costs.