Caring For Dogs With Sugar Diabetes (Diabetes Mellitus)

By Dr Joanna De Klerk

When it comes to canine diabetes, you’ll probably be surprised to hear that it’s more common than you think. We hear about it all the time in humans, and maybe you’re wondering if dog diabetes is the same? Or maybe your furry pal has just been diagnosed with diabetes, and you’re wanting to find out the best way to care for him. In this article we will explore common questions about diabetes in dogs to ensure your pooch gets the best care there is!

What is Diabetes Mellitus?

There are two types of diabetes; diabetes mellitus and diabetes insipidus. Here, we are going to explore diabetes mellitus, which is when your dog struggles to control their blood glucose (sugar) levels.

Like humans, there are two types of diabetes mellitus; type I and II. 

Type I diabetes is when your pup cannot produce a hormone called insulin. It is usually produced by the pancreas and helps cells to utilise glucose for energy. This can be a genetic problem, or as a result of damage to the pancreas from a disease called pancreatitis.

Type II diabetes is more common in cats than dogs, but obese dogs can develop it. It is when the pancreas can produce insulin, but the body has become resistant to it.

Either way, both type I and II result in less glucose being absorbed into the cells, and more glucose left in the bloodstream, which can lead to some nasty symptoms.

Symptoms of Diabetes in Dogs

At first you might not notice your dog displaying symptoms of diabetes, because they can be pretty subtle. Typical diabetes symptoms can also be symptoms of many other diseases too, and as a result, might get overlooked. However, all symptoms, no matter how subtle, should be checked out by a veterinarian sooner rather than later.

The most common symptoms are:

  • Recurrent urine infections: These happen because the excess glucose in the blood spills over into the urine. Usually glucose is not present in the urine, but when it is, it provides a perfect environment for bacteria to grow. This can result in your dog wanting to pee much more than normal, and it might also smell bad, contain blood, or urination may be painful.
  • Excessive drinking: Because your pooch’s blood glucose level is high, he will feel excessively thirsty. It’s the body’s natural response to try to dilute it. He is likely to want to drink loads of water, which can also lead to excessive urination.
  • Change in appetite: At first, your furry friend is likely to want to eat more, because the cells are not getting the glucose they need for energy, which leads the body to think it needs to obtain more energy from more food. Later in the disease, your dog might then lose his appetite if the blood glucose level gets too high, because it will cause him to feel nauseous.
  • Eye problems: Diabetes can lead to increased pressure in the eye, known as glaucoma. It is a painful condition, and can result in blindness. In addition to that, diabetes can cause cataracts to form in the lens of the eye, which can also cause blindness.

Looking After a Dog with Diabetes Mellitus

If you’ve recently had a dog diagnosed with diabetes, you might be feeling a little overwhelmed. However, fear not. Most cases of diabetes can be managed easily throughout your dog’s life, as long as he is provided with diligent care.


The aim of treatment for diabetes is to reduce your dog’s blood glucose level. For most dogs, this requires twice daily injections with insulin (the hormone your dog is deficient in). 

Don’t expect miracles from the first injection. It can take several months to fine-tune the dose which your dog needs, and therefore you need to work closely with your vet. This might involve weekly trips at first for monitoring.

If you are worried about the idea of injecting your dog, let your vet know. They will be more than happy to teach you an effective technique. You can even practice injecting an orange with water first, so you can get the idea of how to use the syringe and needle. 

When you are ready to inject your dog for the first time, ask your vet to clip a little bit of hair away on the back of their neck, so you can see exactly where to inject. This also helps your check that the needle goes into the skin effectively. 

You might be concerned about your pooch’s reaction to the needle, but insulin needles are tiny so most dogs barely feel it. If you inject when they are distracted, such as while they’re eating, chances are they won’t even realise.

In addition to injections, you should also consider weight management for your dog. You will have much more success in managing your dog’s blood glucose level if they are lean, versus if they are overweight. We will discuss the ideal diet for a diabetic dog next.

Finally, if you have a female, you should consider having her spayed. Reproductive hormones can wreak havoc with blood glucose levels, and again, you’ll find it much easier to manage her diabetes if she has had the operation.


Diabetic dogs need to be on a strict diet. But this doesn’t necessarily mean a diet to lose weight, especially if your dog is currently an optimum weight. Nevertheless, if you have a slightly podgy pup, losing some weight is going to help a lot.

A diabetic dog diet starts with strict meal times. Insulin should always be given at the time of a meal, or just afterwards, as if it is given on an empty stomach, the blood glucose level will drop too low. So, if your dog is a grazer, this is going to have to change. A morning and evening meal, 12 hours apart is ideal.

In between meals, unfortunately your pupster isn’t allowed any calorific treats. This is because they will increase the blood glucose level at a time when insulin is not given. If you need to give your dog something, try a treat which your furry pal can gnaw on rather than eat, such as a deer antler.

Finally, a veterinary recommended diet will help control your dog’s diabetes. Fibre is key, as a high-fibre level makes the body more responsive to insulin, so less insulin is needed. There are several options out there for diabetic dogs, which are specifically made by prescription diet companies. These are particularly good because they also have low levels of starch and easily digestible carbohydrates, making it easier to regulate your pooch’s glucose supply.

Ongoing Monitoring

Once you’ve established what your pup’s ideal dosage of insulin is, you’ll want to keep a close eye on your furry friend with regular monitoring. Once every three to six months, your veterinarian will want to perform a blood glucose curve, which requires them to come into the vet practice for the day, and having their blood glucose reading taken once an hour. This allows your vet to draw a graph of your furbaby’s results and work out the timings and levels of the glucose peak and dip. As a result, treatment plans can be fine-tuned further.

Once your dog has been stable for over a year, your vet might decide to take blood to measure a fructosamine level instead of doing blood glucose curves. This is related to your dog’s blood glucose level over the last two weeks, and if generally under control, it will be within the normal reference range. As a result, your furchild doesn’t need to be left at the vets for the day, and can come home with you straight after.

What is a Diabetic Emergency?

There comes a time for many diabetic dogs when they might have a diabetic crisis and will require emergency treatment. This is far more likely if you have been a bit slack about dosing your pup or not giving accurate doses.

If the blood glucose level becomes extremely low, this is known as hypoglycaemia. It can lead to seizures and a coma, and needs urgent medical attention. It can be caused by giving too much insulin (which is why you should never inject a second time if you’re not sure if it all went in or can’t remember whether you have already given it or not), giving the insulin at the wrong time, or giving the insulin without your dog eating at the same time.

Another concern is ketoacidosis. This is when the blood glucose levels have been too high for a long time. Symptoms include vomiting, lethargy and a sweet smell to the breath. It can be life-threatening and cause organ failure. This is most commonly caused by failure to take your dog for monitoring appointments to fine-tune his dose, or constantly forgetting to give the injections.

It is worth preparing for one of these to happen one day, and having an emergency plan with your veterinarian in place.

What Does the Future Hold?

So, you might be wondering what the prognosis is for a dog with diabetes. If poorly managed, erratic glucose levels can have a major toll on the body and shorten your dog’s life. But the good news is, if you provide your pup with diligent care and are dedicated to working with your vet to alter his treatment plan, he can live a long, happy life without any problems at all.

Take Home Message

Diabetes in dogs is more common than you think, and the initial symptoms are subtle, so if you’re concerned about your dog, take him to your vet for a check-up. The earlier diabetes is successfully controlled, the better the outcome. But try not to worry. Even if you’ve only picked it up further down the line, with diligent monitoring from you and your vet, your dog can live a happy and healthy life.