Diabetes is not just a disease of humans — animals can be affected as well, including household pets. This disease equally as important to control in dogs and cats as it is in their owners.
Diabetes (or, more properly, diabetes mellitus) is a medical condition in which the ability of insulin to regulate blood sugar has been compromised. Instead of being transported into cells with the help of insulin, sugar builds up in the blood. The kidneys cannot appropriately filter this increased load, so sugar spills into the urine. This acts as a diuretic, pulling more water from the body’s circulation into the urine, leading to dehydration. Meanwhile, with the cells in the body being deprived of energy-creating sugar, the protein and fat stores in the body are broken down in an effort to supply more energy.
The symptoms of diabetes are often quite apparent to pet owners. The increased urine volume leads to frequent urination; pets may be asking to be let out more frequently, often urinate larger amounts at one time, and may be urinating in in abnormal places because they can’t hold it to get outside or to a litter box. The resulting dehydration causes increased thirst—thus, the water bowl may empty faster than usual. Increased thirst and urination are the most commonly seen symptoms of diabetes.
Pets with diabetes also usually have an increased appetite, triggered by the body’s cells starving for sugar. However, despite the increased food intake, the pet will likely lose significant weight from protein and fat breakdown. Because the energy contained in the sugar is not being effectively used by the body, pets with diabetes often have increasing lethargy.
Diabetic animals are predisposed to other conditions as well. For example, the sugar present in the bladder creates a favorable environment for bacteria to grow; thus, diabetic pets often have concurrent urinary tract infections. Dogs with diabetes often develop cataracts as a result of the way the lens processes sugar. Diabetic cats may develop nerve weakness. They may not jump as high as they used to, and they may stand with their hocks (rear “ankles”) on the ground instead tip-toed with their hocks up in the air.
The most dangerous effect of diabetes is known as ketoacidosis. As fat stores are broken down in the body, they are turned into ketones, which the body can use to create energy. However, if an animal has unregulated diabetes for a length of time, or experiences a stressful condition while diabetic, the ketones build up to dangerous levels. This affects the body’s acid/base and electrolyte balance, which disrupts many of the body’s normal processes. Symptoms include vomiting, decreased appetite, profound lethargy, and seizures. Ketoacidosis is a life-threatening condition that needs to be aggressively treated on an emergency basis.
The various symptoms mentioned above do not guarantee that a pet has diabetes, as there are other diseases that create the same or similar issues. If these symptoms are present, the pet should be evaluated as soon as possible by a veterinarian. A diagnosis of diabetes (or other condition) will be based on an analysis of the pet’s symptoms, a physical exam, and laboratory test results.
The mainstay of diabetes treatment in dogs is insulin supplementation. Many diabetic cats need insulin injections as well, although some mild cases may be treated with a special diet alone. Those pets that do need insulin are given injections under the skin once to twice daily, sometimes with the one of the same types of insulin used in humans. The needles on insulin syringes are very small, so most pets tolerate the injections well, and most owners find it easy to learn to give the injections.
Diabetic pets started on treatment will need periodic monitoring of their blood sugar levels to determine if the dose of insulin is appropriate. Both underdosing (and thus having uncontrolled diabetes) and overdosing (leading to dangerously low blood sugar) can have significant impacts on a pet’s health. It can take from weeks to months of fine-tuning before the blood sugar is brought under acceptable control, and the dose may even need to be changed as time goes by. Dogs with diabetes require lifelong insulin treatment. However, some cats—even those that initially require insulin—will achieve remission of diabetes through the use of special diets.
While a diagnosis of diabetes in a pet can be daunting, animals that achieve good control of their diabetes and secondary medical issues can potentially lead long lives with minimal symptoms.
— Keith Rode is a veterinarian at Woodland Veterinary Hospital and a graduate of UC Davis. For more information, call 530-666-2461.