Glucose: What Is It, How It's Made and Why It's Needed

Posted by Michelle for PetTest, AAHA Certified Diabetes Educator on Jul 28th 2021

Glucose:  What Is It, How It's Made and Why It's Needed

Today we are going to talk about how glucose is produced in our dog's bodies, not to be confused with glucose that is a form of simple sugars we find in many fruits, root vegetables like beets and carrots, sugar cane and corn. We all know our dogs have higher blood glucose levels and twice daily insulin injections are necessary. But what is glucose? How is glucose made? How is it used? Today I am going to break it all down for you, so grab a cup of your favorite caffeinated beverage and let’s get to it!

What is glucose?

Glucose is the byproduct of foods that are eaten and is the main source of energy that feeds the body’s cells. Glucose is utilized by humans and mammals, insects, reptiles and even plants. Glucose is vital to all life!

How is glucose made?

Glucose is made by the body breaking down food, this starts in the mouth with chewing and saliva. Saliva has enzymes that start to break down food. Once in the stomach, food is digested further into a semi fluid called chyme. Chyme consists of partially digested food, digestive juices and hydrochloric acid. Chyme moves down to the small intestine. The pancreas releases a bicarbonate to neutralize the acidic digestive juices and releases enzymes to break down the food into nutrients. Nutrients that consist of glycogen (aka carbohydrates), proteins, fat, water and minerals are then absorbed by the small intestine. The hepatic portal vein absorbs these nutrients and delivers then to the liver for further breakdown and the liver is where the magic happens!

In a process called glycogenolysis, the liver metabolizes glycogen into glucose. The liver stores and releases glucose into the blood stream as necessary. During a hypoglycemic episode the liver jumps into action and dumps glucose into the blood stream as an emergency response to save the body from critically low blood glucose levels.

How is glucose used?

Glucose is used by cells as energy or food. The brain, kidneys, liver, muscles all depend on glucose as the main source of energy. The biggest user of glucose is the brain, it uses half of the glucose that the body produces.

Glucose cannot be used as energy by itself, it requires insulin. The pancreas produces insulin and insulin is what opens the cell receptors to accept glucose for energy. Without insulin glucose builds up in the blood stream, the liver produces ketone bodies for use as alternative energy. Build up of ketones in the body is called diabetic ketoacidosis (DKA). This is very serious illness that requires immediate medical attention. To read more about ketones and diabetic ketoacidosis (DKA) please click here.

Insulin and Glucose for PT

While glucose is vital to every living thing, we do not all carry glucose in the same manner. Blood is made up of plasma and red blood cells. Glucose is carried in blood by both the plasma and red blood cells, but each species carries different percentages of glucose in plasma and red blood cells.

Glucose Distribution for PT

­Glucose distribution is why it is important to have a species appropriate blood glucose meter. A blood glucose meter uses algorithms made for specific species; human meters read human blood, animal meters read either cat or dog blood but need to be coded to the appropriate species. While we can use some human meters to test our dog’s blood glucose levels, the readings may be off due to glucose distribution being different between dogs and humans.

Interesting Facts: Hypo and Raw Fed for PT

I hope that you have a better understanding of what glucose is, how it is made and why it necessary. Us parents of diabetic dogs need to help that glucose with insulin injections, but we got this!


Until next week, stay cool and caffeinated!

If you have any questions, comments or suggestions, please start a conversation below.

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For a printable version of this blog click here.