Diabetes in Dogs - VOSD Vet

What is Diabetes Mellitus in Dogs?

Diabetes Mellitus in dogs is a prevalent condition characterized by insufficient insulin production or inadequate response to insulin. It is a disorder of the endocrine system, which regulates various bodily functions, including metabolism.

Insulin plays a crucial role in converting food into energy. After a dog consumes a meal, nutrients are absorbed into the bloodstream as glucose, also known as blood sugar. Every cell in the body relies on glucose for energy.

Insulin facilitates the movement of glucose from the bloodstream into cells by binding to receptors on cell surfaces. This allows cells to utilize glucose for energy production or storage. In the absence of sufficient insulin, cells are deprived of glucose, leading to an energy deficit. Simultaneously, high blood glucose levels in the bloodstream can cause damage to nerves and blood vessels. The treatment of diabetes mellitus in dogs typically involves administering insulin to enhance glucose uptake by cells and lower blood glucose levels.

There are three types of diabetes that affect dogs:

Type I, known as insulin-dependent diabetes, resembles Type I diabetes in humans and is the most common in dogs. In Type I diabetes, insulin-secreting cells in the pancreas are destroyed, leading to a complete lack of insulin. Dogs with Type I diabetes require lifelong insulin supplementation to maintain normalcy.

Type II, referred to as noninsulin-dependent diabetes, mirrors Type II diabetes in humans and is often associated with obesity. In Type II diabetes, the pancreas may produce insufficient insulin, and the body’s cells respond poorly to the insulin produced. Consequently, less glucose enters the cells, resulting in elevated blood glucose levels.

Type III diabetes, hormone-induced and usually linked to pregnancy, is rare in dogs but can be fatal. Although dogs may return to normal after pregnancy, Type III diabetes can recur in subsequent pregnancies. Due to the risks involved, veterinarians often recommend spaying a dog as soon as it is medically safe to do so.

Irrespective of type, reduced glucose levels in the body’s cells prompt the liver to produce more glucose, exacerbating blood sugar levels. The kidneys filter and absorb the excess glucose from the bloodstream, but the overflow of glucose into the urine leads to excessive urination and thirst in dogs.

Excessive sugar levels can also lead to:

Bladder infections
Loss of muscle mass
Liver damage

Approximately 1 in 300 dogs develop diabetes during their lifetime, with females and middle-aged to senior dogs at higher risk, particularly if they are obese. Certain breeds are predisposed to diabetes, including:

Alaskan Malamute
Australian Terrier
Bichon Frise
Cairn Terrier
Keeshond
Labrador Retriever
Miniature Schnauzer
Miniature Dachshund
Norwegian Elkhound
Poodle
Pug
Samoyed
Tibetan Terrier
Yorkshire Terrier

Symptoms and Types

The signs of diabetes most frequently observed include:

Increased thirst (polydipsia)
Increased urination (polyuria)
Increased appetite (polyphagia)
Weight loss
Lethargy
Dehydration
Cataracts

Common diseases and illnesses such as urinary tract infections, Cushing’s disease, hypothyroidism, and pancreatitis often complicate matters for diabetic dogs. Additionally, diabetic dogs may exhibit further symptoms based on underlying disorders.

If left unregulated or untreated, the long-term effects of diabetes can be severe and ultimately fatal. Some common secondary and long-term effects include the following:

Seizures may occur if the blood sugar drops too low. Proper regulation of glucose is crucial in treating diabetes, but excessive medication can lead to hypoglycemia and seizures, which can be fatal if left untreated. It’s imperative to seek veterinary attention immediately. Your vet might suggest rubbing Karo syrup or similar sugary substances on the gums to alleviate low blood sugar before taking your dog in for examination. Pet owners should only administer Karo syrup or similar products under veterinary guidance when deemed safe to do so.
Hepatopathy, or liver disease, can manifest as a side effect of diabetes. Disrupted fat metabolism leads to elevated levels of fatty acids in the liver, resulting in fat accumulation within liver cells, causing damage and swelling.
Diabetic ketoacidosis (DKA) arises from chronic cellular starvation. The body resorts to alternative fuel sources such as protein and fat tissues, initially producing ketones. However, when ketones accumulate, they trigger metabolic acidosis, acidifying the blood. Dogs with DKA are usually very ill, requiring intensive nursing care and treatment, often in a 24/7 specialty hospital.
Hyperglycemic Hyperosmolar Syndrome (HHS) is a grave complication of diabetes characterized by extremely high blood glucose and osmolality. Osmolality denotes the number of dissolved particles in the bloodstream. Dogs with HHS are typically very ill, necessitating intensive nursing care and treatment, often in a 24/7 specialty hospital.
Diabetic neuropathy, although rare, can develop when chronic diabetes damages the nervous system. Affected pets typically exhibit an abnormal, uncoordinated gait with partial paralysis of the hind legs.
Diabetic cataracts form due to elevated levels of blood glucose within the eye’s lens. While glucose is essential to fuel and energize eye cells, it can become trapped within the lens, leading to the formation of cataracts.

Causes

Diabetes mellitus in dogs stems from several causes, with most dogs developing Type I, or insulin-dependent diabetes. Type I diabetes often occurs when the immune system erroneously attacks insulin-producing cells in the pancreas, resulting in either complete or partial loss of insulin secretion.

Various factors contribute to the risks and complexities of diabetes, including genetics, hormones, and other illnesses. Genetic predisposition is likely a significant factor in many instances of diabetes, explaining why certain breeds are more susceptible to the condition.

Elevated levels of hormones such as progesterone, growth hormone, and cortisol can induce glucose intolerance, with gestational diabetes being the most prevalent form of hormone-related diabetes.

Cushing’s disease, another endocrine disorder, elevates cortisol levels in the body, making it challenging to regulate diabetes in affected dogs. Veterinarians routinely screen for Cushing’s disease in newly diagnosed or challenging diabetic cases.

Chronic pancreatitis, characterized by inflammation of the pancreas, can destroy beta cells responsible for insulin production, potentially leading to diabetes. Moreover, obesity and high-fat diets can trigger pancreatitis and may serve as risk factors for developing diabetes in dogs.

Diagnosis

Veterinarians often suspect diabetes mellitus based on physical examination findings and a history of increased thirst, frequent urination, and weight loss. However, for an official diagnosis of diabetes, veterinarians need to identify consistent high levels of glucose in both blood and urine samples. Veterinarians may suggest the following tests:

Blood chemistry and complete blood count (CBC): These tests help veterinarians detect elevated blood glucose levels and often reveal increased liver values, elevated cholesterol, kidney values, and changes in electrolyte levels.
Urinalysis: This examination indicates persistent high levels of glucose in the urine, a common indicator of diabetes. It can also reveal the presence of urinary tract infections, which are frequently observed in diabetic dogs. Failure to treat urinary tract infections can complicate diabetes management. Additionally, urinalysis provides insights into ketone levels, helping to rule out diabetic ketoacidosis, a potentially severe complication.
Fructosamine test: Some dogs may experience stress-induced increases in blood glucose levels, leading to inaccurate readings, especially in the stressful environment of a veterinary clinic. A fructosamine test aids in confirming a diabetic diagnosis and serves as a valuable monitoring tool. While blood glucose readings offer immediate information, fructosamine assays provide insights into insulin regulation over the preceding two to three weeks.

Further diagnostic procedures may be necessary to eliminate concurrent disease processes, including:

Radiography to identify co-existing conditions such as kidney or bladder stones, cystitis, and pancreatitis.
Thyroid tests to rule out thyroid disorders, a common endocrine ailment.
Cushing’s disease testing.
Abdominal ultrasonography to detect additional conditions like pancreatitis and hepatopathy.
Pancreatitis blood testing.

Treatment

For cases of diabetes that are uncomplicated, meaning they do not involve diabetic ketoacidosis or similar complications, the primary treatment consists of insulin administration and dietary modifications.

Insulin for Diabetic Dogs

Insulin serves as the primary treatment for dogs with diabetes. Its role involves facilitating the movement of glucose from the bloodstream into the cells, where it can either be utilized or stored. Insulin is administered subcutaneously, meaning it is injected under the skin. Most dogs typically require insulin injections twice a day. Despite the initial apprehension, administering insulin injections is usually well-tolerated by dogs, as the amount of insulin required is generally small and the needles used are tiny.

Veterinarians or veterinary technicians can provide demonstrations on how to administer insulin injections, or they may approve video tutorials for guidance. It’s important to vary the injection sites to prevent the formation of scar tissue, which could hinder proper insulin absorption if it occurs.

Types

Insulin comes in two different strength levels: U-100 and U-40, indicating the number of units of insulin contained in one milliliter. U-100 insulin is more concentrated, with 100 units per milliliter, while U-40 insulin contains 40 units per milliliter.

It’s crucial that the insulin syringes correspond to the type of insulin being used. Using a U-100 needle with U-40 insulin can lead to incorrect insulin dosing for the dog, potentially resulting in serious complications.

Veterinarians commonly prescribe the brand Vetsulin for diabetic dogs. Other types of insulin that may be prescribed include:

Lantus
Prozinc
Detemir (Levemir)
NPH

Diets for Diabetic Dogs

Diet therapy plays a crucial role in the treatment of diabetes. Pet owners should aim to feed their dogs the same food, at roughly the same times each day. Consistency is paramount and contributes to more effective and rapid regulation of blood sugar levels.

Prescription diets specifically designed for diabetic dogs are available. These diets typically feature high fiber content along with appropriate ratios of fat, protein, and carbohydrates, aiding in the maintenance of stable blood sugar levels. It’s important to note that pet owners with underweight dogs or those experiencing other symptoms related to diabetes should consult their veterinarian before making any dietary changes.

Potential Treatments for Diabetes in Dogs

Gene therapy is emerging as a promising treatment option for diabetes in dogs. Research indicates that gene therapy has the potential to decrease the amount of insulin needed for management. Although it’s not a cure, gene therapy shows promise in offering assistance to dogs with diabetes in the future.

Recovery and Management of Diabetes in Dogs

Dogs diagnosed with diabetes necessitate lifelong monitoring and treatment, requiring collaboration between pet owners and their veterinary teams for effective management.

Initially, veterinarians typically conduct blood sugar level checks 4 to 6 hours after the initial insulin dose to rule out episodes of low blood sugar. Additional assessments are often performed, usually within the veterinary hospital setting.

Following the initial evaluation, dogs should undergo assessments every 7 to 14 days. Adjustments to insulin doses should not be made more frequently than every 7 days unless there is suspicion of a low blood sugar crisis.

It’s imperative that adjustments to insulin doses are made only under the direct supervision of a veterinarian. Once diabetes is regulated, dogs should undergo physical examinations, including weight checks, at least every three months. Comprehensive blood work and diabetic testing may also be conducted at least every six months.

There are four primary methods to monitor a dog’s response to insulin treatment:

Blood glucose curve is the most accurate way to monitor a dog’s blood sugar levels. Dogs remain at the veterinary hospital throughout the day, with blood drawn every 1 to 2 hours. These values are plotted on a chart, resembling a curve. Based on the curve’s shape, as well as the highest and lowest blood glucose levels, veterinarians determine if a change in dosage is necessary.
Freestyle Libre involves the painless placement of a small sensor on the dog’s skin to measure blood glucose levels. Glucose can be checked frequently, without the need for blood draws, using a device reader or smartphone app. This method is particularly useful for dogs that may be anxious or uncooperative.
Fructosamine provides a general indication of glucose regulation over the past 2 to 3 weeks. While not ideal, it can be helpful when other methods are not feasible due to financial constraints or the dog’s behavior.
Urine glucose and ketone measurements offer an easy and cost-effective way to monitor dogs at home. A small strip is placed in the urine stream for testing. A negative test result could indicate a low blood sugar event, necessitating a call to the veterinarian. Additionally, the test strip detects ketones in the urine, which should ideally be negative. Persistent high ketone levels in the urine could indicate diabetic ketoacidosis (DKA) and poor regulation.

Management goals include alleviating signs and symptoms, maintaining healthy blood glucose levels, and enhancing the dog’s quality of life.

Therapeutic goals for dogs differ from those for humans with diabetes. Veterinarians typically do not aim to control glucose levels in dogs as tightly as in humans. Consequently, target blood glucose readings for dogs may be higher than those familiar to pet parents accustomed to human diabetic management.

The prognosis for diabetic dogs depends on various factors:

Uncomplicated cases of diabetes are generally easier to regulate, requiring only a few veterinary visits per year for monitoring.
Complicated diabetes cases can be challenging and frustrating to manage for both pet owners and veterinarians. Treating complicated diabetes can be financially and emotionally draining, and unfortunately, diabetic dogs are sometimes euthanized due to the difficulty of management. Therefore, it is crucial for pet owners to discuss goals and expectations with their veterinarian at the time of diagnosis and to maintain open communication throughout the treatment process.

Prevention

Although diabetes is not entirely preventable in dogs, there are proactive measures pet parents can take. Regular veterinary care is essential for all dogs. Annual general physical exams and routine blood work are recommended for all dogs, while senior dogs, typically over the age of 6, should visit the vet every six months. These examinations and blood tests can detect changes well before they manifest as clinical signs. Consequently, dogs can receive prompt treatment or lifestyle adjustments before they become ill, leading to an improved quality of life and an extended lifespan.

In addition to consistent veterinary check-ups, pet parents can promote their dog’s health by providing a high-quality diet and ensuring regular exercise to maintain a lean and active lifestyle.

Diabetes in Dogs FAQs

Do certain foods trigger diabetes in dogs?

While high-fat diets can lead to pancreatitis, which might predispose dogs to diabetes, there isn’t a confirmed direct link between specific diets and diabetes.

What is the life expectancy for dogs after a diabetes diagnosis?

Depending on any concurrent health conditions and how easily regulated the diabetes is, dogs can live for many years after diagnosis. However, some studies suggest a mean survival time of 18 to 24 months after diagnosis.

Which type of diabetes is more prevalent in dogs?

Type I diabetes is the most common form observed in dogs.

Can puppies develop diabetes?

While most dogs diagnosed with diabetes are typically middle-aged to mature, there are juvenile forms of diabetes that can affect puppies.

Does diabetes in dogs lead to blindness?

When blood sugar levels become extremely elevated and are trapped in the lens of the eye, it can result in the formation of cataracts. Without treatment for cataracts, a dog may ultimately go blind.