They are the words every pet owner fears to hear, " I'm afraid your pet might have cancer." 

What brings us, as your veterinarian, to have this concern?

The road to cancer diagnosis and treatment is widely varied.  First, there are many terms associated with cancer

  • tumors
  • masses
  • nodules
  • neoplasia
  • benign
  • malignant
  • remission
  • cure. 

The first three words relate to identifying something growing on or in your pet that shouldn't be there.  It may be something that can be just monitored, but no extra measures are required or it may be something that requires additional tests and potential treatments like surgery, chemotherapy, or radiation therapy.  The later words in the list are specifically related to cancer, its level of severity, and the ability to return your pet to a decent quality of life for as long as possible.

How do we diagnose cancer in your pet?

Growths on the outside of your pet are usually quickly noticed either by yourself or by us during a physical exam.  Some can be deemed to be low risk, such as warts (also called papillomas), cysts that contain fluid or oily secretions, or fibrotic skin reactions.  If we have any doubt about the type of growth, we may recommend a needle aspirate, where we try to pull out some cells and look at them under the microscope.  If the aspirate doesn't tell us what we are dealing with, we may also recommend a biopsy, where we surgically remove some or all of the mass for a pathologist to aid our diagnosis.  Most skin cancers are effectively treated by early diagnosis and surgical removal.  If your pet has a more aggressive form of skin cancer, you will be given a choice to pursue treatment with a cancer specialist, called an oncologist, to better your pet's chances of eliminating or slowing the cancer.  More on that in a minute

Unfortunately, cancer inside your pet is more difficult to diagnose.  There is no "cancer test" that universally tells us when a pet has cancer.  We become concerned that we may be dealing with cancer when we have a pet who is not thriving, possibly losing weight, may have less energy, and developing other persistent abnormal symptoms, especially if the pet is middle-aged and older.   A physical exam may or may not reveal internal masses.  Bloodwork helps us eliminate diseases that can mimic cancer, such as kidney failure, from the list of possibilities causing your pet's symptoms.  Ultimately, internal cancer is diagnosed by some combination of radiographs ( X-Rays), ultrasound, ultrasound-guided needle aspirate, MRI, and possibly endoscopic or surgical biopsy.

The needle aspirates and biopsies help us classify the growths. They may be benign, meaning the growth may continue to get larger but is not destructive to the tissues around it, not likely to spread to other areas of the body, and not creating and releasing toxic chemicals that sicken your pet.  Fatty tumors are a typical example, which is very common in older pets, and rarely need to be removed (usually only because they are interfering with the normal function of a limb).  However, other tumors may be malignant, locally destructive, and damaging the organ they occupy, potentially spreading especially to the lungs and liver, and having widespread negative effects on other areas of your pet's body. 

So what causes cancer in pets? 

This is the question researchers continue to pursue. There are some known connections, such as un-neutered male dogs that are at a greater risk for anal cancer, and unspayed female dogs are at greater risk for mammary cancer. But most cancers are caused by a cancer gene that gets "turned on." We don't know why one pet's genes will turn on when most others don't.

What can treatment look like?

In the sad event that one of our patients develops cancer, we still have weapons with which to fight it.  Some cancers can be successfully treated by surgical removal alone.  Others may need combinations of surgery and chemotherapy or radiation therapy.  The good news is unlike people, many of these treatments have minimal impact on the pet's quality of life.  They may cause temporary fatigue, some suppression of white and red blood cell counts, occasionally slight (<24 hr duration) nausea, usually controlled by medication, and some skin irritation, comparable to a sunburn.  So the harsh symptoms people often experience going through human cancer treatment are not seen as often in pets.  The length of time the pet remains free of cancer symptoms ( remission) can be highly variable.  But at the ratio of one dog year to seven human years, even six months to a year can be a significant increase in life expectancy over 2-6 weeks when not treated.

Treatment can be expensive and time-consuming (a good reason to invest in pet insurance when they were young). You will get the most accurate information on the quality of life and the expected length of remission when you meet with your oncologists.  Many pet owners go to the first office visit with the oncologist unsure if they want to pursue treatment or not.  It is a valuable resource to give the pet owner all the information as they face their decisions. 

Whether you pursue treatment or not, we are here to help keep your pet feeling as good as possible for as long as possible and help with any questions you may have.