This dog cancer is a tumor derived from the cells lining blood vessels. Since blood vessels run through the body, hemangiosarcoma can develop anywhere. However, it is more common on the skin, spleen, liver, and heart. Hemangiosarcoma accounts for approximately 5% of cancer cases in dogs, usually affecting middle-aged and older dogs.

Hemangiosarcoma develops slowly and painless, making it hard to detect at first. The most common clinical sign is an enlarged spleen diagnosed by palpation or through radiology or ultrasound. This cancer can affect any breed but is mainly found in German shepherds, golden retrievers, and Labrador retrievers.

A mast cell tumor (MCT) comprises healthy cells that have grouped and formed a mass. It is primarily found in the skin; however, it can appear in other body parts like the respiratory and digestive tracks. This cancer can be relatively benign and easily treatable with surgery. However, it can also spread and be aggressive.

MCT can affect any dog but is most common on older dogs, with boxers, bull terriers, Boston terriers, and Labrador retrievers being the more susceptible breeds.

Lymphoma cancer is one of the most diagnosed in dogs. Lymphoid tissues can present in many places in the body, including the spleen, liver, gastrointestinal tract, bone marrow, and most commonly in the peripheral lymph nodes. This form of cancer is considered treatable if diagnosed in its early stages.

This form of dog cancer can affect any dog, no matter the breed or age. However, it is mainly found in golden retrievers and dogs between the ages of 6 and 9. Other dogs breeds with a high incidence of lymphoma are Poodles and Australian shepherds.

Osteosarcoma canine cancer has the same appearance as human pediatric osteosarcoma. It is formed by tumors that arise from the abnormal production of cells that create and break a bone. This form of dog cancer is the most common type of primary bone cancer in dogs.

The most common affected area is long bones like arms and legs, but it can also affect bones like the shoulders, pelvis, or hips. A primary symptom is swelling or lameness in the affected area.

Osteosarcoma mainly affects older large or giant breed dogs.

The most common form of brain cancer in dogs is a meningioma or a glioma. This type of cancer is difficult to detect, with the only symptoms often being epileptic-like seizures, extreme behavioral changes, and ear infections.

Dogs of any sex older than five years are at a higher risk of getting brain tumor cancer.

Bladder Cancer is a slow developing cancer, and symptoms don't usually show for 3 to 6 months. The most common type of bladder cancer in dogs is transitional cell carcinoma (TCC). TCC is most common in the urinary bladder but can also appear in the kidney, uterus, urethra, prostate, or vagina.

Transitional cell carcinoma cancer accounts for 1% of cancer in dogs, most found on Shetland sheepdogs, Scottish terriers, Wirehair fox terriers, West Highland terriers, and Beagles.

Mammary Carcinoma is the most common tumor diagnosed in female dogs, especially non-spayed ones. Most mammary tumors are found when owners are petting or grooming their pets. Approximately 50% of these tumors are malignant, and surgical removal is recommended.

Malignant Histiocytosis is uncommon cancer in dogs, often presented on large sports breeds. This disease involves an abnormal accumulation of a type of white blood cell called the histiocyte. Unfortunately, there is no effective therapy for this dog cancer, and death typically happened within weeks to months of the diagnosis. Common symptoms are poor appetite, weight loss, and lethargy.

Squamous Cell Carcinomas (SCC) is a tumor of skin cells. Tumors can develop anywhere squamous cells are present, but most commonly in the mouth and the nail beds of toes. This tumor usually appears as a single, solitary lesion in one location, and complete surgical removal is the most common treatment.

Fewer than 20% of dogs develop this disease, but if they do, they are most likely to be Scottish terriers, Pekingese boxer dogs, Poodles, and Norwegian elkhounds. SCC is also most common in dogs that are sparsely-haired and have light-colored hair and skin. Still, any dog can get it.

Nasal tumors make up about 1-2% of all canine cancers, and about 89% of the nasal tumors are malignant. Therefore, early aggressive treatment is essential. Mouth cancer symptoms may include a mass on the gums, bleeding, odor, or difficulty eating. Nose cancer symptoms may consist of nosebleed, difficulty breathing, or facial swelling.

Melanoma involves tumors that originate from melanocytes, pigment-producing cells responsible for coloring the skin. Therefore, it is most common in dogs with dark skin. This cancer is mainly found as masses or lumps on the skin. However, they quickly spread to distant parts of the body, making complete surgical removal impossible.

Melanoma commonly affects Chow Chows, Cocker spaniels, Poodles, and Schnauzers.

This form of cancer affects male dogs and is standard on unneutered dogs with retained testes over ten years old. Testicular cancer presents mainly on Afghan hound, Boxer, Collies, German shepherd, Maltese, Shetland sheepdog, and Weimaraner.