Cancer is an uncontrolled malignant growth or tumor caused by abnormal cell division. Cancer can spread to other parts of the body through the lymphatic system or the blood stream. Generally speaking, cancer is usually associated with the organ it affects and termed as such. Skin cancer is the most prevalent cancer in dogs and along with cancer of the mammary glands it forms nearly 58% of all cancers in dogs.
Carcinoma and sarcoma, the two out of the four major types of cancer, are the ones that normally occur in the skin of a dog that need to be differentiated for treatment purposes. Skin cancer usually affects four different types of cells and is divided into four categories as such.
- Epithelial tumors are associated with the skin, skin glands and hair follicles.
- Mesenchyme tumors are cancers resulting from cells that support fat, connective tissue, blood vessels and nerves.
- Round cell tumors include cancer of the external sex organs, mast cell tumors and plasma cell tumors.
- Melanomas are cancer of the cells responsible for pigment in the skin.
Squamous cell carcinoma is the most common form of skin cancer. Carcinoma is a term that denotes to a cancer that initially starts in the cells and surrounds an organ completely. Another form of carcinoma, basal cell carcinoma, grows gradually and does not normally spread to other parts of the body.
Another common form of skin cancer is associated with mast cells that control coagulation of blood and permeability of blood vessels. Mast cell tumors are usually malignant and arise from connective tissue. Allergic reactions may activate mast cell in a manner that any genetic or environmental predisposition can result in transforming these cells into a cancerous state.
The symptoms of liver cancer in dogs and cancers associated with other organs bring about symptoms like diarrhea, appetite loss, seizures, weight loss and certain immune mediated ailments. Waiting for clinical symptoms of skin cancer, however, can often result in delay of treatment.
Detecting signs of skin cancer requires regular examination of the skin of your dog, preferably at monthly intervals. Take a close look at the skin beneath the hair and look for any new growth, change in color and increase in size of any previous growth. Tumors that bleed easily or lesions and abrasions that do not heal even after treatment should be reported to a veterinarian immediately. Similarly a swelling in the breast tissue or a discharge oozing from the nipples also requires immediate attention of a specialist. Make sure that you check the entire body including the base of the tail.
Treatment of skin cancer is similar to treatment of other types of cancer. Depending upon the stage to which the cancer has developed, chemotherapy, radiation and/or surgical excision of tumor are three options.
Apart from ensuring a healthy and a natural diet, all that you can do to prevent skin cancer is not to expose your dog to known carcinogens. Dogs that have a family history of skin cancer, especially mast cell tumors, are more predisposed to develop skin cancer from exposure to allergens due to the hereditary genetic defects. Exposure to sun, which is a major reason behind feline cancer of the skin, can be equally risky for dogs with a light colored skin.