Cancers

• Canine transmissible venereal tumor is a tumor of the genitals. It is spread by sexual contact.
  
• Hemangiosarcoma is an aggressive tumor in dogs, usually affecting the heart or spleen and less commonly the skin.
  
• Osteosarcoma is an aggressive bone tumor in dogs that commonly spreads to the lungs. It is more common in large and giant breed dogs.
  
• Histiocytoma is a benign skin tumor in dogs that sometimes regresses without treatment.
  
• Malignant histiocytosis is a disease found primarily in the Bernese Mountain Dog characterized by infiltration of the lungs, lymph nodes, and other organs by histiocytes.
  
• A mast cell tumor (mastocytoma) is a type of tumor normally found in the skin of dogs. It can also invade the subcutis and spread to the liver, spleen, or bone marrow.
  
• Lymphoma (lymphosarcoma) is a malignant cancer that is classified by location, cell type, and histological grade. The most common form in dogs is multicentric, involving the lymph nodes.
  
• Fibrosarcoma is a malignant tumor that most commonly occurs in the mouth in dogs, and less commonly in the skin, subcutis, and bones.
  
• Squamous cell carcinoma is a malignant tumor in dogs that most commonly occurs in the oral cavity, including the tongue, tonsils, and gingiva. Squamous cell carcinoma accounts for 5 percent of skin tumors in dogs, and are the most common tumor of the toe. Dogs with unpigmented skin on the nose may develop this cancer from long-term sun exposure.
  
• Perianal gland tumor (also called hepatoid tumor) is a type of tumor found near the anus in dogs that arises from specialized glandular tissue found in the perineum. They are most common in intact (not neutered) male dogs.
  
• Anal sac adenocarcinoma is an uncommon and aggressive malignant tumor found in dogs that arises from the tissue of anal sac.
  
• Melanomas account for four to six percent of skin tumors in dogs and are usually benign. They are the second most common tumor of the toe and are malignant in this location. Malignant melanoma is also a common oral tumor in dogs. Malignant tumors most commonly spread to the lymph nodes and lungs.
  
• Leukemias are progressive proliferation of cancerous white blood cells within the bone marrow, resulting in destruction of the bone marrow and pancytopenia in many cases. Types of leukemia in dogs include acute lymphoblastic leukemia, acute myelocytic leukemia, acute monocytic leukemia, acute myelomonocytic leukemia, acute megakaryocytic leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, chronic basophilic leukemia, and chronic eosinophilic leukemia (or hypereosinophilic syndrome).
  
• Plasmacytomas are common skin tumors in dogs that derive from B lymphocytes. Most are benign. Tumors of B lymphocyte origin that affect the bone marrow and are diffuse throughout the body are malignant and are called multiple myeloma.
  
• Prostate cancer is rare in dogs and occurs in both intact and neutered animals. It is malignant. The most common type is adenocarcinoma. Signs include blood in the urine and straining to urinate or defecate. It most commonly spreads to bone and the lungs.
  
• Mammary tumors in dogs are potentially benign or malignant. They occur most commonly in non-spayed females or female that were spayed later in life.
  
• Insulinomas in dogs are insulin secreting tumors of the pancreas. The most common sign is hypoglycemia. They commonly metastasize to the liver.
  
• Oral cancer includes tumors of the tongue, tonsils, gingiva, and palate. The most common types are squamous cell carcinomas, malignant melanomas, and fibrosarcomas.
  
• Ocular tumors in dogs are found in the eyelid, conjunctiva, third eyelid, cornea, sclera, iris, ciliary body, retina, choroid, optic nerve, and orbit. The most common types are Meibomian gland adenoma (eyelid), papilloma (eyelid), melanoma (eyelid, conjunctiva, sclera, iris, ciliary body, choroid), squamous cell carcinoma (conjunctiva), adenoma (ciliary body), adenocarcinoma (ciliary body), lymphoma (retina, choroid, ciliary body), medulloepithelioma (retina, choroid), ganglioglioma (retina, choroid), osteosarcoma (orbit), mast cell tumor (orbit), and optic nerve sheath meningioma.
  
• Nasal cancer makes up one to two percent of all types of tumors in dogs. Adenocarcinoma is the most common type, followed by sarcomas such as fiborsarcoma and chondrosarcoma. Signs include sneezing and bloody nasal discharge.
  
• Thyroid cancer is rare and usually nonproductive in dogs (unlike in cats, in which it causes hyperthyroidism). One-third of thyroid tumors are small benign adenomas; the rest are malignant carcinomas, usually large and invasive.
  
• Gastrointestinal cancer is uncommon in dogs. The most common type is lymphoma. Nonlymphomatous esophageal cancer is especially rare, the most common types being squamous cell carcinoma, adenocarcinoma, leiomyosarcoma, and osteogenic sarcoma associated with the parasite Spirocerca lupi. Nonlymphomatous stomach cancer is usually an adenocarcinoma, and nonlymphomatous intestinal cancer is usually polyps, adenomas, adenocarcinomas, leiomyosarcomas, and leiomyomas.
  
• Kidney cancer is uncommon in dogs. The most common type is renal cell carcinoma.
  
• Lung cancer is usually the result of metastasis in dogs. Primary tumors are rare. The most common type is adenocarcinoma.
  
• Heart tumors are rare in dogs. Types include hemangiosarcoma, fibrosarcoma, and fibroma.
  
• Testicular tumors are the most common tumor of the canine male reproductive tract. Tumor types include Sertoli cell tumor, seminoma, and interstitial cell tumor. None commonly metastasize.
  
• Ovarian cancer is uncommon in dogs, with the most common type being the granulosa cell tumor. This type of tumor can metastasize and can cause cystic endometrial hyperplasia.
  
• Uterine cancer is very rare in dogs. The most common type is benign leiomyoma.
  
• Bladder cancer is usually malignant in dogs. The most common type is transitional cell carcinoma.
  
• Liver cancer is usually metastatic in dogs. Primary tumors are and include benign hepatocellular adenoma (hepatoma) and malignant hepatic carcinoids.
  
• Brain tumors can be either metastatic or primary in dogs. The incidence of primary tumors is 14.5 per 100,000 dogs at risk. Types include meningioma, astrocytoma, oligodendroglioma, and undifferentiated sarcoma.