Diabetes Mellitus

We have a video explaining Diabetes in the Dog that we can lend to you free of charge.  Please contact us to obtain a copy

What is diabetes mellitus?

Diabetes mellitus is a common disorder and is most often seen in dogs 5 years of age or older.  Diabetes mellitus arises from a failure of the pancreas to regulate blood sugar.  The pancreas is a small but vital organ that is located near the stomach. It has two significant populations of cells. One group of cells produces the enzymes necessary for proper digestion. The other group, called beta-cells, produces insulin. 

People with diabetes have injections of insulin or take oral medication.   Is this true for dogs?

In humans, two types of diabetes mellitus have been discovered, they each have different mechanisms of disease.

1. Type I, or Insulin Dependent Diabetes Mellitus, results from total or near-complete destruction of the beta-cells of the pancreas. This is the only type of diabetes known in dogs. As the name implies, dogs with this type of diabetes require insulin injections to stabilise blood sugar.

2. Type II, or Non-Insulin Dependent Diabetes Mellitus, is different because some insulin-producing cells remain. However, the amount of insulin produced is insufficient and there is a delayed response in secreting it. People with this form may be treated with an oral drug that stimulates the remaining functional cells to produce or release insulin in an adequate amount to normalise blood sugar. Type II diabetes is rare in dogs; generally oral medications are not appropriate for treating diabetic dogs.

Why is insulin so important?

The role of insulin is much like that of a gatekeeper: it stands at the surface of body cells and opens the door, allowing glucose to leave the blood stream and pass inside the cells. Glucose is a vital substance that provides much of the energy needed for life, and it must work inside the cells. Without an adequate amount of insulin, glucose in unable to get into the cells. It accumulates in the blood, setting in motion a series of events which can ultimately prove fatal.

When insulin is deficient, the cells become starved for a source of energy. In response to this, the body starts breaking down stores of fat and protein to use as alternative energy sources. As a consequence, the dog eats more; thus, we have weight loss in a dog with a ravenous appetite. The body tries to eliminate the excess glucose by excreting it in the urine. High levels of glucose in the urine also draws more water into the urine resulting in the production of a large amount of urine. To avoid dehydration, the dog drinks more and more water. Thus, we have the four classical signs of diabetes: 

CLASSICAL SIGNS OF DIABETES MELLITUS

How is diabetes mellitus diagnosed?

The diagnosis of diabetes mellitus is based on three criteria: the four classical clinical signs, the presence of a persistently high level of blood glucose and the presence of glucose in the urine. 

The normal level of glucose in the blood is 4.4-6.6 mmol/l. It may rise to 10 mmol/l following a large meal. However, diabetes is the only common disease that will cause the blood glucose level to rise above 22 mmol/l. Some diabetic dogs will have a glucose level as high as 44 mmol/l, although most will be in the range of 22-33 mmol/l.

To prevent glucose loss from the body the kidneys only allow it to pass out in the urine when very high levels of glucose are circulating in the blood. This means that dogs with a normal blood glucose level will not have glucose in the urine. Diabetic dogs, however, have excessive amounts of glucose in the blood, so it will be present in the urine.

What are the implications for me and my dog?

For the diabetic dog, one reality exists: blood glucose cannot be normalised without treatment. Although the dog can go a day or so without treatment and not get into a crisis, treatment should be looked upon as part of the dog's daily routine. Treatment almost always requires administration of insulin and some modification of the diet.

For the owner, there are two implications: financial commitment and personal commitment. 

When your dog is well regulated, the maintenance costs are minimal. The special diet, insulin, and syringes are not very expensive. However, the financial commitment is significant during the initial stabilisation process and if complications arise.

Initially, your dog may be hospitalised for a few days to deal with any immediate crisis and to begin the stabilisation process. The initial hospitalisation for stabilisation averages from two days to one week or more.  Time is needed to formulate a regime that suits your dog and discover the necessary amount of insulin needed to maintain normal blood sugar levels.  Dogs with advanced, untreated diabetes will become very ill.  They may vomit, stop eating and drinking, and will eventually fall into a coma.   Dogs in this state, called ketoacidosis, often require a week or more of hospitalisation, intensive fluid therapy and laboratory tests.  Once stabilised your dog will return home for you to continue to administer the required medication. At first, return visits are required frequently to monitor progress.   Once your dog is settled into a regime only periodic blood tests and check-ups will be required to monitor progress.

The financial commitment may again be significant if complications arise. We will work with you to try and achieve consistent regulation, but a few dogs are difficult to keep regulated. It is important that you pay close attention to our instructions related to administration of medication, to diet, and to home monitoring. Another complication that can arise is hypoglycemia, or low blood sugar. If severe, this can be fatal. This may occur due to inconsistencies in treatment. This will be explained in subsequent paragraphs.

Your personal commitment to treating your dog is very important in maintaining regulation and preventing crises. Most diabetic dogs require insulin injections once or even twice daily. They must be fed the same food in the same amount on the same schedule every day. If you are out of town, your dog must receive proper treatment while you are gone. These factors should be considered carefully before deciding to commence treatment.

What is involved in treatment?

Consistency is vital to proper management of the diabetic dog. Your dog needs consistent administration of medication, consistent feeding, and a stable, stress-free lifestyle. 

1. Insulin does not cause pain when it is injected.

2. The injections are made with very tiny needles that your dog hardly feels. The injected volumes are minute.

3. The injections are given just under the skin in areas in which it is impossible to cause damage to any vital organ. Please do not decide whether to treat your dog with insulin until we have demonstrated the injection technique. You will be pleasantly surprised at how easy it is.

About Insulin

Insulin comes in an small, airtight bottle.  As it is a hormone that will lose its effectiveness if exposed to direct sunlight or high temperatures, it should be kept in the refrigerator, but it should not be frozen. It is not ruined if left out of the refrigerator for a day or two, although this is not advisable. Insulin is safe as long as it is used as directed, but it should be kept out of the reach of children.

Drawing the insulin into the syringe:

1. Shake the bottle to mix the contents. Some of the types of insulin used in dogs have a strong tendency to settle out of suspension. If it is not shaken properly it will not mix well, and dosing will not be accurate. Therefore, the trick is to shake it vigorously enough to mix it without creating foam. Since bubbles can be removed (as described later), it is more important to mix it well than to worry about foam formation.

2. Remove the guard from the needle, and draw back the plunger to the appropriate dose level.

3. Carefully insert the needle into the bottle through the centre of the rubber lid.

4. Inject air into the bottle; this prevents a vacuum from forming within the bottle.

5. Withdraw the correct amount of insulin into the syringe.

6. Before injecting your dog with the insulin, check that there are no air bubbles in the syringe. If you get an air bubble, draw twice as much insulin into the syringe as you need. Then withdraw the needle from the insulin bottle and tap the barrel of the syringe with your finger to make the air bubble rise to the nozzle of the syringe. Gently and slowly expel the air bubble by moving the plunger upward.

7. Check that you have the correct amount of insulin in the syringe. The dose of insulin should be measured to the end of the plunger nearest the needle.

The injection technique is as follows:

1. Hold the syringe in your right hand (switch hands if you are left-handed).

2. Pick up a tented fold of skin from the scruff of your dog's neck (pick a different spot each day).

3. Quickly push the very sharp, very thin needle through your dog's skin. This should be easy and painless. However, take care to push the needle through only one layer of skin and not into your finger or through two layers of skin. The latter will result in injecting the insulin straight through the skin onto the  floor. 

4. Withdraw the plunger a little to check that you have not entered a blood vessel.  If you see blood in the barrel of the syringe withdraw the needle completely and start again.

5. To inject the insulin, place your thumb on the plunger and push it all the way into the syringe barrel.

6. Withdraw the needle from your dog's skin. Immediately place the needle guard over the needle and store the needle and syringe back in the fridge. The needle and syringe can be reused many times over.

7. Stroke your dog to reward it for sitting quietly.

8. Be aware that councils have strict rules about disposal of sharp medical waste material so don't throw the syringe into the rubbish.  We can dispose of them safely for you. 

Note: It is not necessary nor desirable to swab the skin with alcohol first. 

Although the above procedures may at first seem complicated and somewhat overwhelming, they will very quickly become second nature. Your dog will soon learn that each day it has to sit still for a few minutes. In most cases, a reward of stroking results in a fully cooperative dog that eventually may not even need to be held.

How do I check on the progress of my dog?

It is necessary that your dog's progress be checked on a regular basis. Monitoring is a joint project on which owners and veterinary surgeon must work together.

A) Home Monitoring
You will need to monitor your diabetic dog in two ways:

Firstly,  it is important to take note of variations in your dog's

We will provide you with a chart on which you can record many of the above observations.  Always bring this to the surgery when you visit with your dog for a check-up so that the veterinary surgeon can study it, it may help in diagnosing a problem.

Secondly, determining the level of glucose in the urine

Fresh urine needs to be collected each morning and tested with urine glucose test strips.  Only a small amount of urine is needed to perform the test.  The test only takes a matter of seconds to do and is very simple.  The result of this test determines the amount of insulin that you need to give your dog for that day.   The strips, which we will supply to you, also measure for the presence of ketones in the urine.  Ketones indicate that the diabetes is not properly controlled.  If you detect ketones then we should see your dog for a check-up. 

B) Veterinary Monitoring 
Determining the level of glucose in the blood is the most accurate means of monitoring. This should be done about every 3-4 months if your dog seems to be well regulated. It should also be done at any time the clinical signs of diabetes are present or if appreciable amounts of glucose are detected in the urine for several days.

Timing is important when the blood glucose is determined. Since eating will elevate the blood sugar for several hours, it is best to test the blood at least 6 hours after eating.  As the blood glucose levels vary throughout the day we usually need to take several blood glucose measurements to get an accurate picture.  We are mostly interested in what the highest and lowest glucose readings are for the day.

If your dog is to be admitted for the day for blood glucose monitoring then please follow this procedure:

1. Bring your dog to the hospital at 8.30 am without giving it insulin or food.

2. Please bring your dog's usual food, insulin and daily regime (bring your chart) 

3. A blood sample will be taken immediately, then we will feed your dog and give insulin.

4. Several blood samples will be taken at regular intervals throughout the day to help us determine when the insulin has its peak effect.

5. If your dog gets excited or very nervous when riding in the car or being in the hospital, the glucose readings may be falsely elevated. If this occurs, it is best to admit your dog to the hospital the morning (or afternoon) before testing so it can settle down for testing the next day. In this way the tests are likely to be more accurate.

Does hypoglycaemia (low blood sugar) occur in dogs?

Yes, and it can be life-threatening.  It occurs under two conditions:

1. If the insulin dose is too high. Although most dogs will require the same dose of insulin for long periods of time, it is possible for the dog's insulin requirements to change. However, the most common causes for change are a reduction in food intake and an increase in exercise or activity. If your dog does not eat, you need to call your veterinarian. Always remember that it is better for the blood sugar to be too high than too low.

2. If too much insulin is given. This can occur because the insulin was not properly measured in the syringe or because two doses were given. You may forget that you gave it and repeat it, or two people in the family may each give a dose. A chart to record insulin administration will help to prevent the dog being treated twice.

The most likely time that a dog will become hypoglycaemic is the time of peak insulin effect (5-8 hours after an insulin injection). When the blood glucose is only mildly low, the dog will be very tired and unresponsive. You may call it and get no response. Within a few hours, the blood glucose will rise, and your dog will return to normal. Since many dogs sleep a lot during the day, this important sign is easily missed. Watch for it; it is the first sign of impending problems. If you notice it, telephone and we will organise blood tests.

If your dog is slow to recover from this period of lethargy, you can try feeding sugar or glucose. A teaspoonful of sugar in a little water given as a drink should bring about an improvement. If not repeat it after 15 minutes.  If there is still no response  contact us immediately for further instructions. 

If severe hypoglycaemia occurs, a dog will have seizures or lose consciousness.  If this happens smear honey or glucose syrup on the gums THEN CALL US IMMEDIATELY, THIS IS AN EMERGENCY.  This can only be reversed with intravenous administration of glucose. 

Copyright © 2002 Penstone Veterinary Group
Last modified: November 30, 2004