As a pet lover it is our prime responsibility to take care of our dog and for that knowledge about concerns related to dogs is important. So, we are here to help you learn more about your buddy. Today we are going to cover the topic Hypoglycemia in dogs, what causes it, how do we manage and diagnose it. Well, the first question on someone’s mind arises is What Is Hypoglycemia in Dogs? The glucose concentrations in clinically normal dogs range from 3.3 mmol/L to 6.2 mmol/L, or 60 mg/dL to 111 mg/dL and when the blood glucose concentration lowers from 3.3 mmol/L or 60 mg/dL, then the condition is known as Hypoglycemia.
Symptoms of hypoglycemia
Clinical symptoms of hypoglycemia in dogs may include altered mentation and behaviour like:
- Syncope (temporary loss of consciousness)
- Muscle twitching/fasciculations (tingling and numbness)
- Somnolence (drowsiness)
- Exercise intolerance
- Muscle tremors
- Ataxia (impaired coordination)
- Impaired vision
However, the clinical sign might vary and are non – specific.
Causes of hypoglycemia in dogs
In the clinically normal animal, the normal concentration of glucose in the blood (euglycemia) is primarily maintained by achieving a balance between the glucose-lowering hormone (insulin) and the glucose-elevating hormones (glucagon, cortisol, epinephrine, norepinephrine, and growth hormone) which are also called diabetic hormones or counterregulatory hormones. And any type of condition which affects the blood glucose level of a dog can cause hypoglycemia but some of the main causes due to which the condition occurs are:
1. Physiological and Iatrogenic causes
- Extreme exercise
Intensive exercise or prolonged activity can result in high levels of glucose consumption and rapid glycogen depletion, especially in lean dogs, resulting in hypoglycemia.
- Juvenile and toy breed
It is common for new-born dogs to develop hypoglycemia due to several factors including limited glycogen reserves, reduced ability of hepatic gluconeogenesis, low body mass index, insufficient lipolysis to provide an alternative fuel source, immature hormonal counterregulatory systems, and a heart that relies heavily on glucose for energy, as well as the brain.
(Means that the amount of insulin in the blood is higher than normal)
Xylitol: This sugar alcohol is used commercially as a sweetener and contains antimicrobial properties. It is commonly found in a variety of products, including candy, gum, toothpaste, and baked goods. Dogs may experience hypoglycemia from xylitol due to its dose-dependent release of insulin, which is 2.5-7 times greater than that from glucose.
2. Pathological causes
Although there are many pathological causes, but some of the common causes are:
It has been proposed that hyperglycemia caused by sepsis results from a combination of factors, such as decreased caloric intake, dysfunction of the liver, and increased insulin-independent glucose consumption by bacteria, neutrophils, and peripheral tissues, all of which are affected by inflammatory mediators and insulin analogs.
- Extra pancreatic neoplasia
Non-pancreatic neoplasms have the ability to cause hypoglycemia, and the mechanism of action is often multifactorial and includes both a paraneoplastic effect through the release of insulin or insulin analogs, as well as direct tumour effects such as excessive glucose utilization by the tumour and impaired hepatic glucose homeostasis resulting from primary liver tumours and liver metastasis.
Insulinomas are pancreatic tumours with insulin-secreting beta cells that cause hypoglycemia independent of normal suppressive effects of normoglycemia or hypoglycemia.
3. Artifactual causes
A dog with apparent hypoglycemia may be experiencing it due to artifactual hypoglycemia caused by using a human-specific portable blood glucose meter. Poor handling of samples can result in pseudohypoglycemia (pseudohypoglycemia refers to a condition in which glucose levels are falsely low), which contributes to artifactual hypoglycemia. To prevent continuous glucose consumption by erythrocytes and leukocytes via glycolysis, blood should be sent to an external reference laboratory in sodium fluoride tubes.
Diagnosis approach to hypoglycemia in dogs
After hypoglycemia has been documented, all spurious causes have been excluded, and the signalment and history of hypoglycemia indicate that there are no overt iatrogenic or physiological causes exist then the clinician will need to devise a list of most likely different diagnosis for pathological cause of hypoglycemia.
The patient’s symptoms, history, physical exam findings, and preliminary diagnostic test results may help narrow down a differential diagnosis. And when the clinician is not presented with any red flags then the systematic approach is followed.
If the test is not already done then the following steps are followed:
- To determine the cause of the symptoms, the clinician should perform a complete blood count (cell count), a biochemistry test, an electrolyte test, and a urine test.
- Clinicians may proceed with a paired insulin and glucose assay if the blood analysis is unremarkable, other than hypoglycemia.
- The diagnosis of insulinoma must be followed by further imaging studies to detect metastases or a pancreatic mass.
- It is still appropriate to proceed with diagnostic imaging, even if the insulin and glucose results are not consistent with insulinomas. To evaluate the thorax and abdomen for an extra-pancreatic mass, for occult infections, such as stump pyometra and pyelonephritis, as well as the liver for abnormalities in the vascular and parenchymal system.
- It is important to offer the patient fasting and postprandial bile acids, a urinary culture, basal cortisol, and ACTH-stimulating tests if they do not have further clues about the cause of hypoglycemia.
- In cases where a clinical diagnosis cannot be made after exploring the more common causes of hypoglycemia, a clinician consults a veterinarian who specializes in internal medicine or emergency and critical care.
Management or treatment for hypoglycemia in dogs
In an emergency situation when the patient is at home, pet parents can apply corn syrup, honey, glucose syrup, or 50% dextrose to the tissues around the mouth, lining the cheek, and then give it by mouth once the patient is able to swallow. Once the patient can swallow, contact an immediate veterinary doctor. And a hypoglycemia patient in the hospital usually receives glucose via intravenous dextrose.
Note: It is always advisable to slowly infuse dextrose solution over a period of 5 to 10 minutes to avoid osmotic diuresis and dehydration caused by excessive dextrose solution. A rapid, large dose of dextrose can also have adverse effects on dogs with insulinomas or extrapancreatic tumours that secrete insulin analogs.
As an alternative to dextrose, glucagon constant rate infusion can be considered when dextrose fails to alleviate hypoglycemia. The glucagon infusions may be especially useful in cases of iatrogenic insulin overdose, insulinoma, or extra pancreatic tumours with hypoglycemia.
We know that people might be still curious about some questions like what toxins mostly cause hypoglycemia. How is it the same or different from humans. Don’t worry we got you.
Q1. What toxins cause hypoglycemia in dogs?
Ans: Xylitol which works as an artificial sweetener is one of the main reasons for hypoglycemia. Other than that, toxins like baclofen, metaldehyde, antihyperglycemic etc are also responsible.
Q2. How it is similar to hypoglycemia in humans?
Ans: The causes of hypoglycemia in humans and dogs are somewhere same. Often intake of sweets, candies, and malnutrition can lead to hypoglycemia in both humans and dogs. The symptoms of hypoglycemia are also similar.
Q3. What is exercise induced hypoglycemia in dogs?
Ans: Exercise-induced hypoglycemia (EIH) refers to low blood sugar levels during and after heavy exercise. A continuous exercise session lasting two or three hours at 65% oxygen uptake causes hypoglycemia in humans. Therefore, hypoglycemia is more than plausible in dogs undertaking extreme exercise in poor body conditions.
Our day-to-day habits not only impact our lifestyle but also our pets and the environment. Hypoglycemia can arise by doing heavy exercises, not eating properly, and eating food with excess sugar. It can even result in life threating situation. So as responsible citizens we have to not induce these types of bad habits, and keep our beloved pets happy and healthy. Eat healthy, stay healthy.