When Do I Euthanize My Pet With Cancer?

When Do I Euthanize My Pet With Cancer?

by Dr. Kari Trotsky
Peaceful Endings for Pets

When your pet is diagnosed with cancer, it can be devastating news. Not only does cancer come in all different shapes and forms affecting different areas such as skin, organs, bones, or nerves, some can be aggressive either spread throughout the body (metastasis), or remain locally, causing its own destructive tissue damage. The main questions that need to be answered are:MassBelly

  • Where is it?
  • What is it (biopsy often needed)?
  • Is there any evidence of spread (metastasis) throughout the body?
  • What are the treatment options (whether you pursue them or not)?
  • What is the prognosis?

Once these questions are answered, only then you can make informed decisions.

If your pet is really old, you may not want to even pursue getting a biopsy, and that’s understandable. Those decisions are personal, and as long as you don’t plan on treating it (meaning trying to get rid of the cancerous cells whether it be through surgery, chemotherapy, or radiation), and know that future outcomes can be unpredictable since we won’t know how the cancer will act (will it be aggressive, will it travel to the lungs, will it cause anemia, etc) then going forward with hospice care is fine. Hospice in this situation would mean treating every symptom within reason (especially pain control) to make the pet as comfortable as possible until the time to euthanize comes.

So, whether you decide not to pursue a biopsy, or if you have pursued full treatment options, but now the end is near anyway, there are a few things that may help you know when it’s time to euthanize your pet.

First, are the symptoms. If your pet has rapid weight loss, is weak, starts to eat less, has vomiting or diarrhea, then it may be time to euthanize. At the first start of, say, vomiting, it’s ok if you get an anti-emetic injection and subcutaneous fluids from your vet to see if it’s an ailment unrelated to the current cancer and will respond to conservative treatment. But barring that, if it’s now going on 2-3 days, waiting any longer will only prolong your pet’s suffering. If your pet is wasting away, feeling so ill that he or she doesn’t want to eat or drink, feels nauseous, or is too weak to go outside or to the litter box to eliminate, then you need to make that ultimate decision.

Next, your pet may have location specific problems, but any issue with the heart and lungs should not be prolonged! If your pet has labored breathing, or an increased respiratory rate at rest, or fluid build-up in the lungs, these conditions all feel horrible and the pet can go downhill very rapidly. With these conditions, the pet either feels like he is suffocating, or that he is drowning in his own fluids. Your pet cannot keep this up for very long. The body will get tired, your pet won’t get much sleep because of the positions he has to maintain in order to breathe, and delaying euthanasia is not advisable.  These pets can also be a little tricky to euthanize because as the sedative (before the final euthanasia injection) starts to take effect, it will depress the respiratory and cardiac centers causing the breathing and heart rate to slow. When this happens, the pet can have trouble breathing. I’ve dealt with this situation many times, and if the pet’s breathing is hampered in any way, it is best to step in sooner than expected and euthanize the pet instead of waiting for the full effect of the sedative to take place.

Another consideration beyond the heart and lungs are other locations in the body. If your pet has a brain tumor, he may not know where he is or who you are. He may act uncharacteristically aggressive and the risk of biting a human could be high. He may go blind or walk into walls. If your pet has an abdominal mass, there may be a risk of that tumor rupturing and bleeding and, thereby, causing internal hemorrhage. This can happen at any time and can be rapid. Or, maybe your pet has a large external tumor. These can start to decay on the inside, progress to an open wound, and cause infection, bleeding and pain. Also, another location could be bone cancer. Often these progress to pathologic fractures (the destruction and lysis of the bone causes the bone to fracture) which cause a lot of pain. These can often spread to the lungs where your pet can have labored breathing (see above), or require so much pain medicine for the pet to be comfortable, that high doses are needed and heavy sedation can occur. Pets shouldn’t be maintained on medications that constantly keep them sedated, so euthanasia will be needed, even though, mentally, your pet may still be very sharp.

This was just a brief overview of the many different sequelae cancer in pets can cause. I’ve dealt with all of these over the course of my 17 years in practice, so if you have any questions, I can certainly help.

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