Diabetes mellitus is a common condition that affects the concentration of glucose, or sugar, in your pet’s blood. Diabetes occurs when your pet’s body makes too little insulin, stops producing it completely, or doesn’t utilize insulin properly, preventing food from converting to energy.

According to the National Library of Medicine, diabetes affects one-third of all dogs. It seems to be more prevalent in certain small breeds such as Miniature Poodles, Dachshunds, Schnauzers, Cairn Terriers, and Beagles, but any breed can be affected.

There are a few different ways to treat diabetes in dogs: diet management, oral hypoglycemic agents (medications that help lower blood sugar levels), and insulin therapy. Your veterinarian will work with you to find the best treatment plan for your dog.

Type I and Type 2 Diabetes Explained

The cause of diabetes is unknown, but it is most likely polygenic (caused by more than one gene) and environmental. There are two primary types of diabetes mellitus in dogs:

  • Type I – Insulin-dependent diabetes mellitus (IDDM) 
  • Type 2 – non-insulin-dependent diabetes mellitus (NIDDM)

Type I diabetes is also juvenile-onset because it usually starts when a dog is young. In type I diabetes, the pancreas stops making insulin altogether. Dogs with type I diabetes take daily insulin injections to regulate their blood sugar levels. Without insulin therapy, these dogs would die within days from a high blood sugar level called diabetic ketoacidosis (DKA).

Type 2 diabetes occurs in mature dogs. Type 2 diabetics still produce some insulin but not enough to maintain normal blood sugar levels without help from medication such as oral hypoglycemic agents or Insulin. Dogs with type 2 diabetes may require prescription medication to keep their blood sugar under control, but they usually don’t need daily insulin injections.

Signs of Diabetes in Dogs

Here are some common signs of diabetes in dogs. If you notice any of these changes in your pet, contact your veterinarian.

  • Excessive thirst and urination
  • Weight loss, even with an increased appetite
  • Lethargy or lack of energy
  • Vomiting and diarrhea
  • Bad breath
  • Cataracts (clouding of the lens of the eye)

How is Diabetes Diagnosed?

The exact cause of diabetes is unknown, although it is believed to be related to genetics as well as lifestyle. Dogs that are overweight and inactive often develop the disease. Your veterinarian will perform a physical examination and take a medical history from you.

A blood test called a serum fructosamine level will be run to measure how well the dog’s insulin levels have been controlled over two to three weeks. Other tests that may be recommended include a urinalysis, complete blood count (CBC), and serum biochemistry profile.

How is Diabetes Treated?

There is no one-size-fits-all answer to this question, as the treatment of diabetes must be tailored to each dog based on his or her specific needs. The goal of treatment is to maintain the dog’s blood sugar at as near normal levels as possible.

Treatment options include:

Diet management and exercise – a diet that is low in carbohydrates and high in fiber can help keep blood sugar levels stable. Regular exercise helps the body use insulin more efficiently.

Insulin therapy – Insulin is a hormone that helps the body use sugar for energy. Nearly all dogs with diabetes require insulin therapy to maintain normal blood sugar levels. There are many different types and brands of insulin available, so it is essential to work with your veterinarian to find the one that works best for your pet.

What Happens Without Insulin?

Insulin is responsible for converting sugar into energy. Without insulin, extra sugar in the blood leads to frequent urination and constant thirst. The body tries to get rid of the sugar by flushing it out in the urine. This can lead to dehydration and loss of essential minerals, such as potassium and sodium. The dog’s cells become starved for energy, leading to weight loss no matter how much they eat. In severe cases, diabetic episodes can be life-threatening.

High blood sugar levels also damage nerves and blood vessels throughout the body over time. Diabetic neuropathy is a common complication that affects the dog’s nervous system, causing him or her to lose coordination, have difficulty walking, and experience changes in sensation (such as numbness or tingling) in the dog’s extremities. Other problems associated with diabetes include cataracts, urinary tract infections, pancreatitis, skin problems, and liver disease.

What Type of Medication is Used?

Insulin therapy is necessary for dogs with IDDM to maintain normal blood sugar levels. There are 3 types of medications used to treat diabetes in dogs: rapid-acting, fast-acting, and long-acting. These medications help the dog’s body make more insulin or use insulin more effectively.  The type of medication prescribed will depend on the severity of the dog’s condition and how well he responds to treatment.

Rapid-acting insulins are generally started at a low dose and then gradually increased as needed. Short-acting insulins are given once a dog begins to respond well to rapid-acting insulin therapy. Long-acting insulin is usually introduced after the pet responds well to short-acting medication.

Veterinarian giving dog injection into the leg

Medications for Insulin-Dependent Diabetes Mellitus (Type I)

Some common types of fast-acting medications include Humulin R (human insulin) and Apidra (glucagon-like peptide-one). These medications must be given by injection using a syringe or an insulin pump. They start working within minutes after administration and provide short-term control of blood sugar levels.

There are many different types and brands of insulin available, so it is crucial to work with your veterinarian to find the one that works best for your pet. Some common brands of insulin used in dogs include:

Apidra (glucagon-like peptide-one) – is a rapid-acting insulin that begins working within 15 minutes of administration and peaks in action within 2 to 4 hours.

Humulin N – intermediate-acting insulin that begins working 90 minutes after injection and peaks within 2 hours, and lasts for 12 to 18 hours.

Vetsulin – intermediate-acting insulin that peaks 4 hours after injection and lass 8 hours

Novolin N –  intermediate-acting insulin that begins working 2-4 hours after injection and peaks in action after 4-12 hours.

Levemir (detemir) – long-acting insulin that starts working one to 2 hours after injection, reaches its peak at 6 to 8 hours and continues providing coverage for up to 24 hours.

Lantus (insulin glargine) – intermediate-acting insulin that provides consistent levels of glucose control for up to 24 hours which is why it may be the best option in some cases. It does not require a change in dosage based on food intake, exercise, or illness as other insulins do. There are many different brands of long-acting human insulin available, including Lantus (glargine), Levemir (detemir), Actos (pioglitazone),

Medications for Non-Insulin-Dependent Diabetes Mellitus (Type 2)

For dogs with NIDDM, diet management and exercise are the primary forms of treatment. A diet low in carbohydrates and high in fiber can help keep blood sugar levels stable, and regular exercise helps the body use insulin more efficiently.

As we mentioned, there are two primary types of diabetes mellitus in dogs: insulin-dependent diabetes mellitus (IDDM), non-insulin-dependent diabetes mellitus (NIDDM).