Finding out your dog has cancer is possibly the worst news a pet parent can get. Depending on the type and severity of the cancer, you'll most likely start thinking about what this means as far as next steps. What can you do to help optimize your dog's quality of life in their final days? How do you know when to euthanize a dog with cancer?

Understand Your Treatment Options

Upon hearing the word "cancer," chemotherapy often comes to mind. There are many kinds of cancer in dogs, and chemotherapy is effective in some but not all. Other cancers (typically those ending in "sarcoma") respond well to radiation therapy. Some cancers require surgery, while others frustratingly evade every treatment option in the book. Get the facts from your veterinarian on your dog's specific type of cancer and the available treatment options.

While chemotherapy and radiation are two of the most common treatment options for cancer in dogs, according to VRC Oncology ,you might be reluctant to pursue them. While they can be costly and time-consuming, some cancers respond well to these therapies. Consider scheduling a consult with an oncologist to learn more about treatment options and to discuss your questions and concerns. During a consult, you're not committed to anything. Think of it more as a safe space where you can weigh the options so you can make a personal, informed choice about what's best for you and your dog.

Some cancers, such as certain lymphomas, respond to a corticosteroid medication called prednisone. A new vaccine is also available for oral melanomas in dogs that uses the dog's own immune system to fight the cancer. Oral chemotherapy options — yes, a pill! — are available as well. Know your options as there might be more than you think.

Senior woman with dog on a walk in an autumn nature.

Know When It's Time to Say Goodbye

No matter which road you choose, the time will come when you'll need to decide when to say goodbye. But how do you know?

When It's an Emergency

Deciding when to euthanize a dog with cancer is clearer in some situations than in others, like emergencies. An example of a sudden emergency is a dog with a brain tumor who's having frequent recurring seizures. Another example could be if your dog has a tumor growing within their spleen that's bleeding into their abdomen (or belly). Emergency situations like this can be emotionally difficult because there's not as much time to prepare. The silver lining is that your decision is clear. In these situations, you don't have to think about when to euthanize a dog with cancer; you just have to act.

When Your Dog's Quality of Life Declines

But what about when the time to euthanize isn't as obvious? Maybe your dog has bone cancer and pain medication isn't helping, or maybe your dog has a liver tumor that's keeping them from eating enough to sustain their desire to play. You want more time with your furry friend, and it can be hard to know when to say goodbye. In these situations, euthanizing is a personal decision that depends on many factors, including your dog's quality of life. Several sites provide quality of life scales to help with this decision, such as The Ohio State University. You'll also want to watch for signs your dog is in pain.

Signs Your Dog Is in Pain

While crying or whimpering can indicate pain, many dogs who are in pain don't make a sound. When you're couch-bound with the flu, you likely lie there quietly rather than groaning the whole time. Dogs are the same way: They'll yelp with acute pain, like you would when stubbing a toe, but they're often silent when experiencing chronic pain.

According to the American Kennel Club, some of the more obvious signs of pain include restlessness, increased breathing rate and trembling, but here are some more subtle signs to watch for:

  • Decreased appetite. Decreased appetite can indicate your dog is experiencing discomfort and losing their zeal for life. This isn't the case for all dogs, though — some dogs eat up until their final breath. It's not safe to assume that your dog isn't in pain just because they're eating.
  • Lack of movement. Reluctance to move is a big one. Has your dog stopped greeting you at the door, waiting for you to come to them instead? Does their range of daily activity entail walking outside to go potty and then coming back in? This is a good indicator that your dog is in pain.

Sometimes these changes are so gradual that it's difficult to notice them. It can be helpful to look at old photos or videos of your dog as a reminder of how they used to act and to give you a basis for comparison. A friend or family member that doesn't see them every day can be helpful as well.

Optimize End-of-Life Nutrition

In addition to learning about treatment options and observing your dog for signs of pain and decreased enjoyment, you'll want to do all you can to keep them comfortable in their final stage of life. Living with and fighting cancer requires substantial nutrients & calories, so some dogs need to be fed extra to account for the tumor that's draining their nutrients. Many dogs will still lose weight (called cachexia) from cancer, but feeding them a high-calorie food can help slow down that process. Check with your vet to determine the best food for your dog.

As you consider when to euthanize a dog with cancer, remember this: There's no one right or wrong answer. Some people think if they don't pick the exact date, they've failed as a pet parent. If you care enough about your dog to read articles and do your best to inform yourself, your dog is in good hands. As you face saying goodbye to your best friend, remember the good times you had, and know that you'll do right by them to the very end. Your dog will love you for it.

Dr. Karen Louis Dr. Karen Louis

Dr. Karen Louis owns her low stress veterinary clinic near St. Louis. When she's not helping dogs and cats live their best lives, she maintains her blog, VetChick.com, and is an award winning nature photographer.

Related articles

Dog Bitten by a Snake? Clinical Symptoms & What You Should Do

Learn about snake bites on dogs, including clinical symptoms to look for, what to do if you think your dog was bitten, and treatment & prevention options.

Laryngeal Paralysis in Dogs

Learn all about laryngeal paralysis in dogs, including types of the condition, signs & symptoms, risk factors, how it's diagnosed and treatment options.

Dog Food Taste & Types: Does My Dog Like Their Food?

Learn about different types of dog foods, why your dog might actually like certain ones over others and questions to ask your vet about dog food taste.

How to Perform the Heimlich Maneuver on a Choking Dog

Learn what to do if your dog starts choking, including how to perform the Heimlich maneuver on a dog, and how to prevent choking hazards in the future.

Dog Tail Signs: What That Wagging Means

Learn how to tell what your dog is feeling from his tail wagging, including what mood he might be in based on the motions and speed of his tail.

Human Foods That Are Dangerous for Your Dog

Read to learn about 5 human foods that are toxic to dogs. Learn their effects on a dog's health and what to do if they accidentally eat one of these foods.

Why Are My Dog's Eyes Red?

Learn common causes of red eyes in dogs, from normal allergies to more serious health concerns, and treatment options your vet might suggest to help.

What to Do if Your Dog Eats a Dead Bird

Learn about potential health issues that can occur if your dog eats a dead bird, such as bacterial & parasite issues, and signs that can indicate sickness.

Pyoderma in Dogs: What You Need to Know

Learn what pyoderma in dogs looks like, what causes it and how nutrition & your dog's food can play a role in preventing and treating the infection.

Dog Dewclaws: What Are They?

Learn why your dog has that extra nail on the side of his paw, what it's purpose is and where it came from.

Training Two Puppies: How to Succeed

Learn how to train two puppies at once with these tips. It's a challenging undertaking, but possible with hard work and love.

Why Does My Dog Eat Everything on Walks?

Why does my dog try to eat everything? Learn how you can prevent your dog from eating stuff off the ground when you're taking him on a walk.

Canine Influenza Vaccine: What You Need to Know

While canine influenza is a newer condition, it can be troublesome for your pup. Learn about dog flu symptoms & which types of dogs should get vaccinated.

Why Is My Dog Afraid of the Dark?

Discover common reasons why your dog seems afraid of the dark, including things like separation anxiety & traumas, and how to help reduce their fears.

Brown Recluse Spider Bite on a Dog: Recognizing It & What to Do

Learn important information about identifying a brown recluse spider bite on a dog, common symptoms of a bite, and what steps you should immediately take.

Understanding and Treating Dog Frostbite

Learn about frostbite on dogs, including areas most prone like the paws, clinical signs of the condition, treatment options and tips for prevention.

Common Health Issues in Puppies

While vaccinations can help guard your dog or puppy against a range of health problems, there are some common dog health problems that can't. Learn more.

Can Dogs Have Celery?

Learn whether celery is bad for your dog, how much is a safe amount, and preparation tips if you think they'll enjoy it as a snack.

Four Ways to Keep Your Adult Dog's Weight Ideal & Healthy

Obesity can cause serious canine health issues, but following these 4 steps to achieve and maintain a healthy weight for your adult dog can help.

How to Choose a Dog Life Jacket

If your dog is often in or around water, a dog life jacket can help keep them safe. Learn which dogs might need one & key features to help you choose.