Cancers can cause a wide variety of signs in your dog and may mimic other disease processes. They are often accompanied by other health problems and may have very nonspecific symptoms. There are many changes you may notice in your dog that prompt you to schedule a veterinary visit. Once you arrive at your veterinarian's, there are a wide variety of tests that can help diagnose cancer and guide the treatment plan.

Symptoms

The signs of cancer are very similar to other common problems or other diseases and depend on the type of cancer and where it is located. These include:

• Bleeding or unusual discharge from any body cavity; blood in urine or feces

• Difficulty breathing, eating, swallowing, defecating, or urinating

• Inability to participate in routine activities, loss of energy, reluctance to move, weakness

• Increased thirst and/or urination, vomiting

• Odd lumps or bumps

• Persistent lameness or stiffness

• Sores that do not heal

• Sudden seizures in older dogs

• Unpleasant, pungent odor

• Weight loss

Virtually all types of cancer at later stages will cause some degree of weight loss. Vomiting, diarrhea, and loss of appetite and stamina may account for this.

Laboratory Tests

During a routine physical, the veterinarian examines the dog's body for lumps and bumps. If there's an odd-looking growth, cells from the lump can be tested in order to make a diagnosis.

To diagnose cancer, the veterinarian runs a blood panel and orders X-rays or ultrasound examinations. A chest X-ray will reveal if the cancer has already spread and an ultrasound can pinpoint an odd growth. A conventional veterinarian or a veterinary oncologist can help assess whether or not additional surgery, radiation, or chemotherapy will be necessary.

Causes of Cancer

Dogs can be predisposed to developing cancer if they are born with a genetically weakened immune system. This makes them more vulnerable to emotional, environmental, and nutritional deficiencies that trigger the disease.

Commercial dog food with inferior ingredients such as animal and grain byproducts, chemical additives, and preservatives is often blamed for causing cancer. Manufactured diets made from organ meats and meat meal have high amounts of growth hormones that are used to fatten cattle. It is speculated that growth hormones and artificial colors cause cancer. There is no scientific evidence proving the link between these additives and cancer, however.

Exposure to too many vaccinations, antibiotics, steroids, environmental toxins, and pesticides impact the immune system. Some of these stimulate the immune system and some of them depress it.