When to Say Yes to a Diagnostic Test

by Nancy Kay, DVM

As veterinarians we have access to so many incredible diagnostic tests. They help us uncover medical issues in our patients that, in the past, we could only guess about. How can you know whether or not to say, 'Yes' to your vet when she or he recommends a diagnostic test, whether advanced or more basic? Here are my suggestions:

Begin by talking with your veterinarian about all the potential risks and benefits and pros and cons associated with the recommended testing. What will be involved for your dog or cat (sedation, general anesthesia, time spent in the hospital) and what will be involved for you (time, expense)? Most importantly, before making a decision about whether or not to proceed with recommended testing, be sure to ask yourself the following two questions:

  1. Will the results of the testing have the potential to change what I do next?

  2. Will the results of the testing have the potential to provide me with some necessary peace of mind?

If your answer to one or both questions is, 'Yes' then it is certainly reasonable to consider proceeding with the diagnostic testing. However, if your answer to both questions is, 'No' the testing is impossible to justify. Not only will it be a waste of your money, why on earth subject your dog or cat to a needless test? Remember, satisfying your veterinarian's curiosity is definitely not a reason to proceed with any recommended testing!

Here are a couple of real life examples excerpted from my practice life that illustrate how the answers to these two questions help in the decision-making process. Shasta is a sweet as can be twelve-year-old Golden Retriever mix, brought to see me because of vomiting and anorexia (food refusal). When I noninvasively looked inside her belly with ultrasound I found multiple masses within the liver, stomach, and spleen. As I told Shasta's mom I was 99% certain I'd identified cancer involving multiple organs. Surgical removal would not be an option (disease too widespread) and the only option for potentially helping Shasta would be chemotherapy, that is, if the cancer were of the type that is responsive to chemotherapy. We discussed performing an ultrasound guided biopsy to 'name the enemy' and know whether or not chemotherapy might be of some benefit. Shasta's mom was clear that, depending on the tumor type, she would wish to give chemotherapy a try. She opted for the biopsy procedure (the biopsy results are pending at the time of this writing). In this case Shasta's medical advocate opted for diagnostic testing because the results had the potential to change what would happen next.

Here's a second example- this time it's Pixel, an eight-year-old mid-sized mutt who presented for coughing. X-rays of his chest revealed multiple lung masses, and I told Pixel's family that I could be 90% certain that they were malignant growths. I left the 10% door open to the slim possibility of an unusual infectious disease. We discussed further diagnostics including a computed tomography (CT) scan of the chest cavity and aspirate or biopsy of a mass in order to 'name the enemy'. With that information we could know whether or not we might be able to provide effective treatment for Pixel. His family members felt certain that if Pixel had cancer they would not wish to treat it. Additionally, 90% certainty that their boy had cancer was good enough for them. Pixel's people had all the peace of mind they needed and the results of the testing would be highly unlikely to change what they would do in terms of treating their little boy. Pixel went home on a cough suppressant and pain medication and is doing reasonably well for the time being.

Have you ever found yourself in a decision-making dilemma concerning diagnostic tests for your pets? If so, would answers to the two questions above have helped you make your choice?

Dr. Nancy Kay, DVM Diplomate, American College of Veterinary Internal Medicine.
Recipient, American Animal Hospital Association 2009 Animal Welfare and Humane Ethics Award Recipient, 2009 Dog Writers Association of America Award for Best Blog Recipient, 2009 Eukanuba Canine Health Award

Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Website: http://speakingforspot.com
Spot’s Blog: "http://www.speakingforspot.com/blog
Email: dr.kay@speakingforspot.com
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