Diabetes Mellitus in Dogs
What Is Diabetes Mellitus?
Diabetes mellitus is an illness that arises due to the body’s inability to either make or use insulin. Insulin is a hormone produced and released by specialised cells in the pancreas. Insulin allows the body’s cells to uptake sugar (glucose) from the bloodstream and use it for metabolism and other functions. Diabetes mellitus develops when the pancreas either does not produce enough insulin or when the body’s cells are unable to use available insulin to uptake glucose from the bloodstream.
Type 1 diabetes mellitus, also known insulin-dependent diabetes, occurs when the pancreas does not make enough insulin to serve the body's needs. Most diabetic dogs have Type 1 diabetes mellitus, meaning that the body fails to make enough insulin to serve its needs. Lifelong administration of insulin is generally required to control diabetes in dogs.
Type 2 diabetes melltius has also been called relative insulin deficiency. This type of diabetes is more common in cats and humans. It occurs when the body’s cells develop insulin resistance, meaning that they are unable to effectively use available insulin.
What are the clinical signs of Diabetes Mellitus in dogs?
Diabetes can exist for a while before it begins to make a pet obviously ill. The clinical signs that the dog exhibits may vary depending on the stage of disease, but they can include any or all the following:
- Increased drinking/thirst
- Increased urination
- Urinary “accidents” in the house
- Weight loss
- Increase or decrease in appetite
- Vomiting
- Dehydration
- Lethargy (tiredness)
How is Diabetes Mellitus diagnosed?
Your veterinarian may suspect that your dog has diabetes if any suspicious clinical signs, such as increased drinking and/or urinating, have been observed at home. After performing a thorough physical examination, your veterinarian may then recommend a number these tests to help confirm the diagnosis:
- Complete blood count (CBC) and biochemistry (organ function tests) - These tests provide important information about your pet’s organ systems. The CBC and chemistry profile may show dehydration, an elevated blood sugar level, and/or other changes that can occur with diabetes.
- Urinalysis - Evaluation of a urine sample may show the presence of sugar (glucose) in the urine if a dog has diabetes. Your veterinarian may also recommend that your pet's urine be checked for evidence of bacteria, as a urinary tract infections are a frequent finding in newly-diagnosed diabetic pets.
- Fructosamine - Fructosamine is a special molecule in the blood that binds very tightly to glucose. The fructosamine level is therefore a close estimation of the blood glucose level, with the added benefit that fructosamine levels are less likely to change due to stress and other factors that can potentially affect the true blood glucose level. Additionally, the fructosamine level indicates where the blood sugar levels have been during the previous 1 to 3 weeks. In a dog with diabetes, the blood sugar levels are usually high for long periods of time, which would be reflected by an increased fructosamine level.
How is Diabetes Mellitus treated?
Insulin injections are generally started at diagnosis and continued for the rest of the pet’s life. Your veterinarian may also recommend dietary changes to help control your dog’s diabetes. It is very helpful to write a medication schedule for your pet on the calendar, including the date and time that the medication needs to be administered, and to maintain accurate records. This will help you to avoid forgetting to give insulin to your pet and allows you to track your pet’s treatment. It is highly important that your pet receives the insulin doses as punctually as possible as this will help to maximise the success of treatment and “normalising” his blood sugar levels.
After treatment begins, the amount of insulin needed by your pet may change after his/her blood sugar level stabilises after a period of time. This means that some pets may need a little more, a little less, or no change in the amount of insulin they receive on a daily basis. Therefore, periodic blood glucose curves, fructosamine and/or urine tests are generally recommended. This information will help your veterinarian to continually ensure that your pet is receiving an adequate amount of insulin that is appropriate for his/her blood sugar levels. Your veterinarian will tailor a specific blood glucose monitoring plan for your pet and inform you when the next recheck would be.
*It is important that you do not change the dose of the insulin without first seeking veterinary advice.*
Your dog’s ability to maintain his/her weight, appetite, drinking and urination, and general attitude at home can all provide useful information that help determine if the diabetes is being well-managed. Your veterinarian will consider all of these factors when making recommendations for continued management.
Many dogs live active, happy lives when their diabetes and blood sugar levels are well-regulated. However, insulin therapy, close monitoring at home and regular rechecks with your veterinarian are important and necessary for the rest of your dog’s life.
Caring for the diabetic pet at home
Here are some helpful tips when caring for a diabetic dog at home:-
- Always feed your pet and administer insulin at the same time of the day.
- Split daily feeding into two meals, approximately twelve hours apart.
- Your veterinarian may also recommend a special prescription diet to assist with your pet's blood sugar control.
- Offer your pet a meal, ensure that he/she has finished the allocated amount, then give the insulin.
- Never give insulin without food, and never give food without insulin.
- Always keep the bottle of insulin refrigerated & stored upright.
- Ensure you are using the correct insulin syringe for the type of insulin your pet has been prescribed.
- e.g. Caninsulin needs to be drawn up with the 40iu/ml insulin syringe, whereas Glargine uses the 100iu/ml insulin syringe.
- Date the bottle of insulin on the day you open it, as different insulin products are stored for different lengths of time once opened
- e.g. Caninsulin should be discarded 6 weeks after opening; whereas Glargine pens/cartridges should be discarded 28 days after opening.
- Ensure that you gently agitate (shake) the bottle of insulin before giving it to your pet.
- Before administering the insulin, always check that the colour and consistency of the insulin solution has not changed or have little precipitates "floaties" that do not dissolve upon shaking the bottle lightly - if you are concerned about the appearance of the insulin solution, please check with your veterinary team if it is still safe to be used
- When you inject the insulin under your pet's skin, be sure to "suck back" on the syringe to check for blood as the insulin must not be injected into a skin blood vessel. If blood is obtained upon "suck back", withdraw the needle completely and find a different location to administer the insulin.
- After administering the insulin injection, feel the skin/coat for any wetness. If you suspect that some of the insulin may have come out during the injection, do not give another dose - make a note of this in your diary and only administer the next insulin dose only when it's due.
- Do not change the insulin dose without first consulting your veterinarian.
- Bring the used insulin syringes/needles back to us at Cahill’s and we will dispose them for you
- Should you accidentally injury yourself with the insulin needle/syringe (that has already been used), please seek immediate medical attention with your family doctor or at an urgent care clinic
- Please phone is approximately 1 week in advance to order your pet's next insulin prescription and insulin syringes before they run out.
Summary of appropriate handling and storage of insulin
- Always keep the bottle of insulin refrigerated upright
- Ensure that you gently agitate (shake) the bottle of insulin before giving it
- Before administering the insulin, always check that the insulin solution is clear and colourless. Caninsulin may be a very light white opaque consistency.
- Do not administer the insulin if you notice that the colour of the insulin solution has changed, become cloudy or have little precipitates ("floaties") in it. In that scenario, please contact us at the clinic to arrange a pharmacy script for a new bottle.
- Always date the bottle of the insulin on the day you have opened it as different types of insulin will need to be discarded after different periods of time once opened.
At-home monitoring of blood glucose levels
Your veterinarian may open a discussion with you about the possibility of monitoring your pet’s blood sugar levels (via a ear prick) and/or urine glucose/ketones at home – this will be on a case-by-case basis. For owners who do monitor the blood glucose and urine at home, please contact us urgently at the clinic for advice if you notice that your dog:
- Has high blood glucose (>25mmol/L) despite receiving the correct dose of insulin; and/or
- Has low blood glucose (<3mmol/L) despite receiving the correct dose of insulin; and/or
- Has ketones present on the urine dipstick
How will I know if things are not going well?
Occasionally, a pet’s blood glucose levels may vary into the “dangerous” levels due to a number of reasons. For example, too high or low insulin dose; development of concurrent illnesses etc – urgent veterinary attention is warranted in such cases. Signs to watch out for are:
- Weakness or lethargy
- Disorientation or bumping into items of furniture
- Sudden collapse or fainting spells
- Seizure activity (convulsions)
- Vomiting
- Loss of appetite
- Weight loss
- Urinating and/or drinking a lot of water
If you notice any of these signs at home, please contact us urgently at the clinic (06) 3588675 to arrange for your dog to be checked over by our veterinarians.
Parts of this handout have been adapted from the VetLearn Compendium careguides.