Cancer

The big “C” scares the heck out us, and rightly so. Dogs get cancer too. Strangely, there have been no epidemiology studies of caner in dogs since the 1960′s. Don’t ask me why, I don’t understand it. Causes of cancer in dogs are very similar to the causes in humans: some are known and some are not. Hormones such as estrogen and testosterone affect canine cancer. Genetic predisposition, and environment are risks as well. One study of Scottish Terriers found a significant increase in bladder cancer for dogs exposed to weed killers and garden insecticides. You might find the following link helpful: www.caninecancerawareness.org

HEMANGIOSARCOMA is a cancer that arises from the blood vessels especially around the spleen, liver, heart, and skin. Symptoms are collapse, pale gums, shockiness, and/or irregular heart rate due to the significant blood loss associated with the fragile tissue rupturing. Hemangiosarcoma is as aggressive and fatal as the other sarcoma type cancers, and survival after surgery and chemotherapy is less than a year.

OSTEOSARCOMA, a type of bone cancer, is found more often in giants like Danes than in smaller dogs. Dogs over 80 pounds are 60% more likely to develop bone cancer. Faster growth rates are a potential factor, as many malignancies are found near the growth plates of the limbs below the elbow. Traumas to bones can also cause bone cancers if the cells trying to repair the fracture mutate into cancerous cells.

No one really knows for certain the causes, but there is a very quick metastisis, or spreading, of cancer to the lungs in Osteosarcoma. It is a very aggressive cancer, and the treatment for it must also be aggressive. Amputation of the affected limb and chemotherapy is the standard treatment, and life expectancy is usually only about a year. This type of cancer is a particularly devastating diagnosis, not only because of the hopeless prognosis, but also the extreme pain the dog suffers.

BREAST CANCER is one of the most common cancers, especially in bitches who have not been spayed before 2 years old.  The risk of malignant mammary tumors in dogs spayed prior to their first heat is 0.05%. It is 8% for dog spayed after one heat, and 26% in dogs spayed after their second heat. This makes it the most preventable of all canine cancers. Most breast cancers are found in the last two mammary glands near the back legs. Simply feeling for lumps in the breast tissues is the best way to detect tumors.

Fortunately, breast cancer surgeries are a good treatment option, and detected early, has a 50% or so chance of not recurring. The one exception is a sarcoma type breast cancer. It is as aggressive and intractable as the bone sarcoma. Surgical removal of canine breast tissue is not the same as a human mastectomy, and the recovery time is much less for dogs than it is for humans.

PROSTATE or TESTICULAR CANCER is rather rare in dogs. A dog neutered before sexual maturity has very little chance of developing testosterone sensitive cancers. A dog neutered after maturity will also have little risk. Intact males after the age of 8 have an 80% higher risk of some type of prostate problems, though cancer still is not as frequent as bone or breast cancer. In the past few years, there has been a greater increase in prostate problems in Danes.

Testicular cancer is very treatable and has a high survival rate. Unfortunately though, if prostate cancer does occur, it spreads rapidly to the liver, kidneys, and lungs. There is some possibility of short term remission from use of chemotherapy, but prostate cancer is incurable and fatal. All the more reason to neuter your dog.