Diabetes is a chronic disease that can affect dogs and cats and other animals (including apes, pigs, and horses) as well as humans. Although diabetes can’t be cured, it can be managed very successfully.
Diabetes mellitus, or “sugar diabetes,” is the type of diabetes seen most often in dogs. It is a metabolism disorder. Metabolism refers to how the body converts food to energy.
To understand what diabetes is, it helps to understand some of this process.
The glucose–insulin connection
The conversion of food nutrients into energy to power the body’s cells involves an ongoing interplay of two things:
• Glucose: essential fuel for the body’s cells. When food is digested, the body breaks down some of the nutrients into glucose, a type of sugar that is a vital source of energy for certain body cells and organs. The glucose is absorbed from the intestines into the blood, which then transports the glucose throughout the body.
• Insulin: in charge of fuel delivery. Meanwhile, an important organ next to the stomach called the pancreas releases the hormone insulin into the body. Insulin acts as a “gatekeeper” that tells cells to grab glucose and other nutrients out of the bloodstream and use them as fuel.
What is diabetes?
With diabetes, the glucose-insulin connection isn’t working as it should. Diabetes occurs in dogs in two forms:
• Insulin-deficiency diabetes—This is when the dog’s body isn’t producing enough insulin. This happens when the pancreas is damaged or otherwise not functioning properly. Dogs with this type of diabetes need daily shots to replace the missing insulin. This is the most common type of diabetes in dogs.
• Insulin-resistance diabetes—This is when the pancreas is producing some insulin, but the dog’s body isn’t utilizing the insulin as it should. The cells aren’t responding to the insulin’s “message,” so glucose isn’t being pulled out of the blood and into the cells. This type of diabetes can especially occur in older, obese dogs.
Female dogs can also develop temporary insulin resistance while in heat or pregnant.
Damage caused by diabetes: A double whammy
Whatever the type of diabetes, the negative effects on the body are the same. Excessive sugar builds up in the dog’s bloodstream, and yet the body’s cells that need that sugar can't access it.
So the “bad” effects that diabetes causes in the dog’s body are twofold:
• Cells are starved for vital “fuel.” Muscle cells and certain organ cells are deprived of the glucose “fuel” they need for energy. In response, the body starts breaking down its own fats and proteins to use as alternative fuel.
• High sugar level in the bloodstream damages many organs. Without insulin to help convert the glucose in the bloodstream into fuel, high levels of glucose build up in the blood. Unfortunately, this abnormal blood chemistry acts like a sort of poison and eventually causes multi-organ damage. This often includes damage to the kidneys, eyes, heart, blood vessels, or nerves.
What are the symptoms of diabetes in dogs?
Early signs. The owner will sometimes notice certain symptoms that can be early signs of diabetes:
- Excessive thirst. The dog may drink frequently and empty the water bowl more often.
- Increased urination. The dog may ask to go outside frequently and may start having “accidents” in the house. Increased urination (and increased thirst) happens because the body is trying to get rid of excess sugar by sending it out through urine, along with water that bonds to the sugar.
- Weight loss. The dog can lose weight despite eating normal portions. This is because the dog isn’t efficiently converting nutrients from its food.
- Increased appetite. The dog can be very hungry all the time because the body’s cells aren’t getting all the glucose they need, even though the dog is eating a normal amount.
Advanced signs. In more advanced cases of diabetes, symptoms can become more pronounced and can include:
- Loss of appetite
- Lack of energy
- Depressed attitude
Threats to health. Uncontrolled diabetes can lead to devastating effects on the dog’s body, which is why early detection and proper treatment are crucial. Effects of diabetes on the dog’s health can include:
- Cataracts (leading to blindness)
- Enlarged liver
- Urinary tract infections
- Kidney failure
- Ketoacidosis, a potentially life-threatening acute condition that can be accompanied by rapid breathing, dehydration, lethargy, vomiting, or sweet-smelling breath; can be triggered by factors such as stress, surgery, fasting, infection, or an underlying health condition combined with low insulin level. Owners of diabetic animals should always have on hand ketone testing sticks and should test their dog's urine if any of the above occurs. If the dog's urine tests positive for ketones, an emergency vet should be called immediately.
Your veterinarian can do simple tests to check for diabetes, including testing for excessive glucose (sugar) in the blood and urine. Blood tests can also show other indications of diabetes, such as high liver enzymes and electrolyte imbalances.
The sooner diabetes is diagnosed and treatment begun, the better chance the pet has of a normal life.
What can make a dog at risk for diabetes?
- Age. While diabetes can occur at any age, it mostly occurs in middle-aged to senior dogs. Most dogs who develop it are age 5 or older when diagnosed.
- Gender. Unspayed female dogs are twice as likely as male dogs to have diabetes.
- Chronic or repeated pancreatitis. Chronic or repeated pancreatitis (inflammation of the pancreas) can eventually cause extensive damage to that organ, resulting in diabetes.
- Obesity. Obesity contributes to insulin resistance and is a risk factor for pancreatitis, which can lead to diabetes.
- Steroid medications. These can cause diabetes when used long-term.
- Cushing’s disease. With Cushing’s disease, the body overproduces steroids internally, so this condition also can cause diabetes.
- Other health conditions. Some autoimmune disorders and viral diseases are also thought to possibly trigger diabetes.
- Genetics. Diabetes can occur in any breed or mixed-breed, and it seems genetics can play a role in either increased or reduced risk. A 2003 study found that overall, mixed-breeds are no less prone to diabetes than are purebreds. Among purebreds, breeds vary in susceptibility, some with very low risk and others with higher risk. Some that may be at higher risk include miniature Poodles, Bichons Frises, Pugs, Dachshunds, Miniature Schnauzers, Puli, Samoyeds, Keeshonds, Australian Terriers, Fox Terriers, Cairn Terriers, and Beagles.
Treatment of diabetes in dogs
- Diet. Your veterinarian will recommend the best type of diet for your diabetic dog. Usually this will include some good-quality protein, as well as fiber and complex carbohydrates that will help to slow absorption of glucose. Your vet may also recommend a diet with relatively low fat content.
- Exercise. To help avoid sudden spikes or drops in glucose levels, it is especially important that diabetic dogs maintain a moderate but consistent exercise routine.
- Injections. Most diabetic dogs will require daily shots of insulin under the skin, something that the owner will have to learn to do. Although it’s understandable to be apprehensive about doing this, it’s not as hard as it might sound. It can become a quick and easy daily routine that isn’t traumatic at all for either dog or owner.
Monitoring and managing your dog’s diabetes
Although some cases may be more challenging, canine diabetes can be usually managed successfully without complications. From giving injections to monitoring glucose levels daily, you will play the primary role in your dog’s care, and your commitment to keeping up with his daily shots and monitoring is extremely important.
Your veterinarian will work with you to determine the best management plan for your dog. At the start of treatment this may involve frequent visits to the clinic for testing and medication adjustments, but hopefully the right combination of medication, dosage, diet, and home monitoring will soon be arrived at that will enable you to keep your dog’s blood sugar consistently regulated and help him live a full, happy life.
Your dog’s diabetes management plan provided by your veterinarian will probably include information about:
• insulin medication for your dog and how to give the injections
• diet and exercise recommendations
• a daily glucose-monitoring system that will work best for your dog
• any warning signs to watch out for
If your pet is diagnosed with diabetes, don’t panic. With good veterinary support, you should be able to provide the right care for your pet and ensure you both many more happy years together.
Note: The information above is designed to help inform you about canine diabetes and is not meant to take the place of a veterinary diagnosis. If you have questions or concerns about your dog’s health or possible symptoms, be sure to contact and consult with your veterinarian right away.
Sources: American Veterinary Medical Association (AVMA), Merck Veterinary Manual, VCA Animal Hospitals, Adelaide Animal Hospitals, PetMD, American College of Veterinary Internal Medicine, and Washington State University College of Veterinary Medicine.