Diabetes with Coma in Dogs

By PetMD Editorial on Jun. 19, 2009

Diabetes Mellitus with Hyperosmolar Coma in Dogs

The pancreas is an organ located in the abdomen, near the stomach. Under normal circumstances, the pancreas makes insulin, a polypeptide hormone that helps to control blood sugar (glucose) levels in the body. When a dog eats food, its blood sugar rises in accordance with the sugars in the food (whether they are natural sugars or not). The pancreas then makes insulin to lower the blood sugar levels to a healthy level. In this way, the other organs in the body are able to absorb and use this sugar for energy.

In the case of diabetes mellitus, the pancreas is not capable of making enough insulin. When this happens, the blood sugar level remains too high, a condition defined as hyperglycemia. A dog's body responds to high blood sugar in several ways. First, extra urine is produced , causing the dog to urinate more frequently than usual. Because it is urinating a lot more, it will drink a lot more water, too. Eventually, your dog will be at risk for becoming dehydrated because of the excess urination.

Because insulin helps the body to use sugar for energy, lack of insulin also means that the body’s organs will not receive enough energy. This will make your dog feel hungry all the time, and though it will be eating a lot more food, it will not gain weight.

If the diabetic condition is not treated early, your dog's blood sugar level will go higher and higher. Because of the excessively elevated glucose level, even more urine will be made and the dog will become dehydrated due to the loss of fluid. This combination of very high blood sugar and dehydration will eventually affect the brain's ability to function normally, leading to depression, seizures and coma. It is rare, however, since symptoms will often warrant a visit to the veterinarian before a pet's health has deteriorated to that level.

Symptoms and Types

Diabetes mellitus without other problems

  • Drinking a lot of water (polydipsia)
  • Urinating a lot (polyuria)
  • Eating a lot but not gaining weight
  • Always seeming hungry
  • Weight loss

Diabetes mellitus with other problems

  • Not wanting to move around much
  • No energy (lethargy)
  • Vomiting
  • Not wanting to eat (anorexia)
  • Lack of excitement or enthusiasm for regular activities (depression)
  • Not responding when called or spoken to
  • Not aware of what’s going on in the environment (stupor)
  • Seizures
  • Confusion
  • Loss of consciousness
  • Coma – long periods with no response to stimuli and inability to be roused


Diabetes Mellitus without complications

  • Pancreas does not make enough insulin

Diabetes Mellitus with complications

  • Pancreas does not make enough insulin
  • Prolonged high blood sugar and dehydration change the way the brain works



You will need to give a thorough history of your dog's health and onset of symptoms. Your veterinarian will perform a thorough physical exam on your dog, taking into account the background history of symptoms that you have provided and possible incidents that might have precipitated this condition. A complete blood count, biochemical profile and urine analysis will be ordered. The veterinarian will use these tests to determine your dog's blood sugar level, water and electrolyte balance, and how well its internal organs are functioning. These tests will also help your veterinarian to determine if there are any other diseases that might be aggravating your dog's diabetes mellitus.


If your dog has been diagnosed with diabetes mellitus but is alert, active, and eating, it will be started on insulin therapy and a special food diet. Some dogs are able to take medications by mouth instead of insulin injections to help control blood sugar.

If your dog has diabetes along with other problems like depression and dehydration, it will be kept in the hospital for several days, where it will be given fluids and insulin until its blood sugar levels have stabilized. It will also be started on a special diet to control blood sugar.

If your dog is diabetic and in a coma, is having seizures, or has almost no energy (is very lethargic), it can be considered to be in a life threatening condition. Your dog will be placed in the intensive care unit of the hospital for several days where your veterinarian can treat it with intravenous (IV) fluids and electrolytes. Your dog's blood sugar and electrolyte level will be determined every few hours until it has stabilized. Your dog will also start receiving insulin to bring down the blood sugar level, and you will be given medications to help control vomiting or other symptoms your dog might have.

While your dog is in the hospital, your veterinarian will be watching for and treating other diseases which can occur while your dog is being stabilized. Some of these are heart failure, kidney failure, bleeding into the intestines, or infections. Getting your dog to the point where it feels better is a slow process, since bringing the blood sugar down too fast could make your dog's health worse. Keep in mind that dog's that have become very ill with diabetes do not do well, especially if they have other diseases concurrent with diabetes.

Living and Management

Once your dog's blood sugar has been brought down and it is able to eat and drink on its own, it will be able to go home with you. Most dogs that have been very sick with diabetes will need insulin. While some dogs are able to take oral medications to help control blood sugar, only your veterinarian can determine whether your dog is a good candidate for oral medications. Your veterinarian will teach you how and when to give insulin injections to your dog, and will also help you to formulate a diet to control its blood sugar levels. It is important to follow all of your veterinarian’s instructions for meals, and for scheduled insulin or medication. Do not change the amount of insulin you give or how often you give it without first consulting with your veterinarian first.

Initially, your dog will need to return for follow-up visits frequently, and there may be times when it will need to remain in the hospital for some of these visits so its blood sugar level can be checked every two hours. Occasionally, some diabetic dogs can become non-diabetics again, but more often affected dogs will need insulin and special food for the rest of their lives. Your veterinarian will discuss with you how to tell if your dog is becoming a non-diabetic again.


To prevent your dog from developing dehydration, seizures or coma because of diabetes, you will need to stick to a regular health and diet schedule, returning to your veterinarian for all follow-up visits. This will ensure that your dog is receiving the correct dosage of insulin.

It will be important to monitor your dog for any changes in its appetite or behavior, including its energy levels. One of the health issues that arises with this condition is a higher frequency of infections, and you will need to have your dog treated quickly before it gets out of hand if this should occur. Consult with your veterinarian as soon as you notice any changes in health or behavior.

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