Facts Hypoglycemia, also called low blood sugar, is an abnormally low concentration of glucose in a dog’s blood. Glucose is produced when the dog consumes carbohydrates, and is used as energy for all the dog’s cells, activity, and basic body function. When the dog produces more glucose than it needs, that glucose converts to glycogen and is stored in the dog’s muscles and liver for it to use in the future. When those stores fill up, the glycogen is converted to fat and stored in fat cells. Hypoglycemia is dangerous because the brain needs glucose to function. When a dog’s blood glucose level is too low, brain damage and death can result.
Causes The glucose level of the blood depends upon the amount of carbohydrates the dog eats, the glucose produced from the liver’s glycogen stores, and the glucose used by the dog’s body. Abnormalities in any of these three areas can cause hypoglycemia. Most cases of canine hypoglycemia occur when the body uses an excessive amount of glucose, when rapidly-dividing cancer cells use the glucose for energy, or when diabetic dogs are given too much insulin. If a dog has high levels of insulin, it will often have hypoglycemia, too. The pancreas creates insulin, which controls the amount of glucose in the blood. Insulin-secreting tumors of the pancreas, liver sarcoma or carcinoma, malignant melanoma, leukemia, sepsis, pregnancy, insulin overdose, prolonged exercise, Addison’s disease, pancreatitis, ingestion of ethylene glycol, renal failure, malnutrition, starvation, or any other type of cancer can cause hypoglycemia.
Prevention For dogs at risk, it is important that they be fed frequently to prevent hypoglycemia. Their diets should be high in complex carbs, fat, and proteins. Hunting or working dogs should have a meal of high fat and protein several hours before being set to work. This will keep their blood sugar levels high enough to keep them going for the duration.
Symptoms Symptoms of hypoglycemia can come and go, they can intensify, or they can be persistent. They may include depression, hind-end paralysis, lethargy, muscle twitching, weakness, bizarre or abnormal behaviour, lack of coordination, exercise intolerance, weight loss, persistent crying, weight gain, collapse, excessive thirst, nervousness, vision abnormalities or blindness, polyphagia, convulsions, reduced activity level, respiratory distress, seizures, high urine output, coma, decreased nursing, low heart rate, and muscle tremors. If you witness any of these symptoms in your dog, get it to the vet as soon as possible. Collapse or coma can result in death; this means that the brain has not received enough glucose to function and emergency treatment is vital if the dog is to survive.
Dogs at Risk Dogs at risk include young puppies, toy breeds, those with cancer, pregnant females, and those with sepsis. Working dogs are also at risk because of the taxing demand on their bodies.
Testing and Diagnosis Compared to some health issues, hypoglycemia is fairly easy to diagnose. A simple blood test will indicate if the dog has low blood sugar levels. The harder part to figure out is why the dog has hypoglycemia, which is actually the most important question. Along with the blood test, the vet should take a patient history, where he or she asks questions about the symptoms and health of the animal, will collect a urine sample for analysis, and will do a thorough exam. If hypoglycemia is suspected right away, your vet may order a fasting blood glucose test, a liver function test, and an ACTH stimulation test, to rule out Addison’s disease. The results of the tests could indicate an underlying cause of hypoglycemia. Other tests may include x-rays of the chest and abdomen to look for tumours, portosystemic shunts, and liver abnormalities.
Treatment and Prognosis The underlying cause(s) of your dog’s low blood sugar must be identified and treated. Once a dog has been diagnosed with hypoglycemia, it will be treated as an in-patient at the clinic to try to raise its blood glucose to a safe level. Frequent meals, IV fluids – including dextrose, and surgery are all possible options. If the dog has an operable tumour that is affecting its blood sugar levels, all attempts must be made to remove it. Other underlying causes should be treated accordingly, which often bring the blood sugar up to normal levels. When the dog has a disease or medical condition that affects the blood sugar and is untreatable, it requires medications to help keep its glucose levels up. In this case, other drugs like diazepam and/or steroids may help. The prognosis depends upon on the severity of the disorder, the underlying cause, and whether that underlying cause is treatable or curable. Pancreatic insulinoma carries with it a poor prognosis. Hunting dogs or lactating females who suffer from overuse of glucose have a much better prognosis, as long as their diets are adjusted to accommodate their special needs.