Three Most Common Fatal Diseases In Dogs

As a dog parent, it is absolutely necessary to perceive the signs and manifestations of normal illnesses so you can look for veterinary assistance for your canine companion quickly. Read this article to get all the important data about sicknesses that often sway dogs.

Common Health Issues in Dogs: Cancer, Diabetes & Heartworm

Discovering that a friend or family member has cancer can be exceptionally frightening and confusing. When that loved one is your dog, the emotions can feel overwhelming. It’s important to remember that different veterinarians may have different perspectives on the best way to treat the illness. Seeking a second opinion—ideally from a veterinary oncologist—is always a wise choice before making any decisions. Carefully reviewing your options ensures that your furry companion gets the most effective treatment possible.

Cancer in Dogs

Cancer is a group of diseases where cells grow uncontrollably, invade surrounding tissues, and may spread to other parts of the body. Just like humans, dogs can develop many different types of cancer. It may remain localized (in one area) or become generalized (spread throughout the body).

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Causes of Cancer

Cancer is considered a “multifactorial” disease, meaning it does not have a single cause. Both genetic and environmental factors can contribute to its development.

Symptoms of Cancer in Dogs

• Lumps (not always cancerous, but should be checked by a vet)

• Swelling

• Persistent wounds that don’t heal

• Unusual discharge from the body

• Bad breath

• Lethargy or loss of energy

• Sudden or unexplained weight loss

• Weakness

• Black, tarry stools (possible sign of ulcers caused by mast cell tumors)

• Loss of appetite

• Difficulty breathing, urinating, or passing stool

Diagnosing Cancer

If a lump is present, the first step is often a needle biopsy to examine the cells. In some cases, surgery may be required to remove part or all of the mass for further testing. Diagnostic tools such as X-rays, ultrasounds, blood tests, and advanced imaging help determine whether cancer is present and if it has spread.

Dogs at Higher Risk

While cancer can occur in any breed, it is more common in older dogs. Certain breeds are genetically more prone—for example:

• Boxers, Boston Terriers, and Golden Retrievers → prone to mast cell tumors and lymphoma.

• Great Danes and Saint Bernards → more likely to develop bone cancer compared to smaller breeds.

Cancer Prevention in Dogs

Spaying or neutering at a young age can significantly reduce the chances of certain cancers. For example, spaying before the first heat cycle almost completely prevents breast cancer in females, while neutering males eliminates the risk of testicular cancer.

Diabetes in Dogs

Diabetes in dogs is a chronic condition caused by either insufficient insulin production or the body’s inability to use insulin properly. After meals, food breaks down into components like glucose. Insulin helps move glucose into the cells. Without proper insulin function, glucose levels rise—leading to hyperglycemia, which can cause serious health issues if untreated.

Good news: Diabetes is a manageable condition, and many dogs with diabetes live long, happy lives with proper care.

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Types of Diabetes in Dogs

• Type I: Insulin-dependent diabetes (most common in dogs). The pancreas doesn’t produce enough insulin.

• Type II: Impaired insulin production combined with an inadequate response to insulin (rare in dogs).

Symptoms of Diabetes

• Change in appetite

• Increased thirst and water intake

• Noticeable weight loss despite eating

• Increased urination

• Breath with a sweet or fruity odor

• Tiredness or lack of energy

• Dehydration

• Urinary tract infections

• Vomiting

• Cataracts or sudden vision loss

• Recurring skin infections

Causes of Diabetes

The exact cause isn’t always clear. However, factors that may contribute include:

• Autoimmune disorders

• Genetic predisposition

• Dogs with higher body weight (linked to insulin resistance)

• Chronic pancreatitis

• Certain medications

• Protein deposits in the pancreas

Dogs More Prone to Diabetes

• Female dogs and dogs with higher body weight may have a higher risk.

• Breeds such as Australian Terriers, Miniature Schnauzers, Dachshunds, Poodles, Keeshonds, and Samoyeds are more likely to develop diabetes.

• Juvenile diabetes may occur in Retrievers and Keeshonds.

Diagnosing Diabetes

Diagnosis requires a combination of medical history, physical exams, blood work, and urinalysis performed by a veterinarian.

Heartworm in Dogs

Heartworm is a serious and potentially deadly parasitic infection. The worms live in the heart and pulmonary arteries of infected dogs, traveling through the bloodstream and damaging vital organs. Within six months of infection, worms can reach the heart and lungs, where they grow up to a foot long.

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Symptoms of Heartworm

• Difficulty breathing

• Coughing

• Vomiting

• Fatigue even after light exercise

• Weight loss or loss of stamina

• In some cases, no visible symptoms until late stages

How Heartworm Spreads

• Transmitted by mosquitoes carrying infective larvae.

• Dogs must be bitten by an infected mosquito for transmission.

• Larvae mature inside the dog and grow into adult worms that reproduce and cause severe damage.

Diagnosing Heartworm

Heartworm disease is diagnosed with blood tests, X-rays, or ultrasounds. Veterinarians recommend annual screenings, especially before starting preventive medications.

Dogs at Higher Risk

Any dog can get heartworm, but those living in hot, humid climates with high mosquito activity are at greater risk.

Prevention of Heartworm

Prevention is simple and affordable. Monthly chewable tablets or topical treatments prescribed by vets can effectively protect dogs against heartworm infection.