CANCER

in dogs is becoming a very common condition and # 1 - killer in all breeds.
Large and giant breeds face a higher risk for bone cancer (osteosarcoma).
Any suspicious lumps, moles, sores or unexplained lameness should be investigated by your veterinarian.

Tumors (any sort of lump, bump, growth or swelling) can be divided into two categories: benign and malignant.

Benign onces don't spread and grow slowly, not invading or destroy other organs.
Malignant tumors are also called carcinomas, sarcomas and lymphomas, depending on the location.

Cancer results in rapid cell division and tissue growth on the host organ. Anything that interrupts the normal pattern of cell duplication can, however, result in the production of mutant cells and those mutant cells reproduce a mass that crowds out normal cells. this mass is called a cancer.

Some cancer-producing genes are inherited and if there aren't any other specific genes that inhibit the cancer-producing onces, cancer will develop.

A predisposition for cancer involves the cancer-producing genes as well as the environment. The predisposition always needs a trigger to produce the cancer (trigger can be any environmental condition such as chemicals, X-rays, viruses, parasites, and stress).

Effective treatment depends on the form of cancer and early diagnosis. Small cancers have a higher rate of cure than large onces. Often a combination of various therapies is more effective (e.g. bone cancer = surgery plus radiation plus chemotherapy).

All immune-supporting-therapies can be of benefit - and support of the immune system in the healthy dog might help to prevent from developing cancer (as some geneticists and biologists feel that weakness of immune system might go along with a higher risk to develop cancer).

Some forms of cancer:

Histiocytosis - a rare malignant cancer in which histiocytes (= large cells in normal connective tissue) are widely spread throughout the tissue and internal organs.
symptoms: lethargy, weight loss, enlargement of liver, spleen and lymph nodes.
In the Bernese Mountaig Dogs this type is known to be inherited.

Mast Cell tumors - can occur in all dogs (Bernese Mountain inheritance is known) and mainly at older age (around 8, 9 yrs.). About 50% are malignant.

Squamous cell Carcinomas - can occur as a hard, flat, grayish ulcer that does not heal; others are a red patch and another cauliflower-like. They invade and metastasise at a late stage to the lymph nodes and lungs.

Lymphoma (Lymphosarcoma) - is a type of cancer that is located in lymph nodes and organs with lymphoid tissue (spleen, liver, bone marrow). It affects mainly dogs at middle-age and older dogs.
symptoms: lethargy, poor appetite, weight-loss. Liver and spleen can be enlarged, fluid in lung and respiratory problems.

Bone cancer - osteosarcoma - this is by far the ost common malignant bone cancer in dogs. It can affect dogs at any age (average age 8 yrs.). Giant breeds (St. Bernard, Newfoundland, Leonberger etc.) face an about 50% higher risk to develop  osteosarcoma than small dogs.
Osteosarcoma occurs most often in the front legs, the hind legs (less often on flat bones or mandibular area).
symptoms: Often only a small limp (with no trauma-injury known) until later swelling of the leg of a large mass is visible. Osteosarcoma is an aggressive form of cancer (spreads mainly to the lungs).

Mammary Gland Tumors - the most common type of tumors in dogs.  It affects mostly bitches of age 6 - 10 yrs. About the half of mammay gland tumors are cancerous.
symptoms: small or large lump. Early detected and removed, survival rate is good, but this type is known for recidives. Mammary gland tumors are know to metastasise pref. in the lung.

Leukemia - this cancer is involving the blood (lymphocytes, monocyts, erythrocytes and other cells). It occurs in middle-aged dogs.
symptoms: not specific, can include fever, loss of appetite and weight loss