When you buy through links on our site, we may earn an affiliate commission.

When To Put Down A Dog With Cancer?

If you have a dog, it is likely that he is part of your family.

In fact, many people are closer to their dogs than they are to human members of their families.

Dogs love so unconditionally, and people really feel free to be themselves around them.

This is why it can be absolutely devastating when you find out that your best furry friend has a terminal illness, such as cancer.

When you find out that your dog has cancer, you know that his days are numbered.

However, it can be difficult to figure out whether you should euthanize your dog or let the illness take its course.

There are few things that you should take into account when you are making this decision.

Every Situation Is Different

Just as is the case with humans, a diagnosis does not tell you everything that you need to know about the situation.

Some people find out that their dogs have cancer after the dog has already taken a rapid downturn in terms of health.

Others find out in the early stages when the dog is still relatively healthy and happy.

Additionally, no matter what type of cancer or what stage it is in, every dog is different.

Every dog has a different body and different body chemistry, which is going to respond differently to cancer.

Your veterinarian can give you some guidance as to how your dog might be feeling, but you can figure out a part of the situation yourself as well.

You are the one who has been with your dog for a long period of time, so you know his personality.

You are the one who can really see if he has changed a lot recently, displaying signs that he is really not feeling well.

Cancer in Dogs

There are many types of cancer that can impact dogs.

Unfortunately, some of these are silent in terms of symptoms, meaning that they will not show up in routine lab testing and not cause your dog to exhibit symptoms until it is too late.

One thing that many people do not know about dogs is that they hide their pain very well.

This is why many people do not know that their dogs are sick until it is too late to do anything about it.

A big part of this goes back to their wolf instincts.

Dogs, just like their wolf ancestors, are pack animals.

When their ancestors were in the wild, they didn’t want to be separated from the rest of the pack.

Dogs and wolves who were not able to keep up with the pack would slow down the entire pack and make it more vulnerable to predators.

Dogs who were old, sick, or weak would be left behind by the pack.

Because even domestic dogs who have never been in the wild are still in touch with their instincts, they really do not want to be left behind by their pack.

Even though you know you would never abandon your sick dog, his instincts tell him that you (his pack) will.

Dogs feel the need to behave as though they are strong and healthy even when they are sick and in pain.

This is why their humans often cannot tell they are sick even though they have a terminal illness that is causing them a great deal of pain.

Decompensation is common in dogs.

Basically, dogs appear to get sick overnight in many cases, even though the illness has been building for a long time.

They may be able to compensate for their symptoms for quite some time, meaning hide their symptoms from their families.

However, there comes a point when the symptoms become too severe, and they are no longer able to hide them, which is decompensation.

Your dog does not want you to know that he is in pain, and he’s going to make his best efforts to hide it until he is no longer able to do so.

Some types of cancer will cause pain, while others will not.

If your dog has a tumor that is pressing on other structures, such as a nasal tumor, brain tumor, or osteosarcoma, it is likely going to be painful.

However, there are other tumors that do not seem to cause a lot of pain in dogs, such as breast tumors.

Unfortunately, because of the way that dogs are likely to hide their pain, you may not know either way for a long time.

Even if a dog is exhibiting signs of pain, it can be tricky to figure out.

Dogs do not communicate using the same language that humans do, so there are other signs that you might want to watch out for to see that your dog might be in pain due to cancer.

Some of these signs are:

  • limping
  • not wanting you to touch him
  • reluctance to using a certain body part
  • hopping like a bunny
  • yelping or whimpering for no reason or when being touched lightly in a certain spot
  • unusual trembling
  • unusual panting
  • sudden trouble climbing up on higher surfaces
  • guarding or hunching over
  • change in appetite
  • aggression
  • behaving apathetically or no longer engaging with things he used to love, and
  • problems urinating or defecating

If you observe any of these signs in your dog, it could mean that he is in pain and should be checked out as soon as possible.

New masses on the body, particularly if they are growing or changing quickly, could also be cancer and are a reason that you should take your dog to the veterinarian as soon as possible.

What to Do When You Find Out Your Dog Has Cancer

Finding out your dog has cancer is every pet parent’s worst nightmare.

However, your course of action now really depends on the situation.

It depends on how well your dog is doing when he is diagnosed.

Your veterinarian will do his or her best to make your dog’s life as happy and comfortable as possible in spite of the diagnosis.

This might mean suggesting a special diet for your dog, scheduling frequent check-ups, controlling any issues that have come up as a result of the cancer, and offering pain management that could potentially be effective.

In some cases, chemotherapy could be an option as well, although it is not a suitable option for every dog that has been diagnosed with cancer.

In order to make your dog as comfortable as possible, you will need to work closely with your veterinarian.

When It Is Time to Say Goodbye to Your Best Friend

Just because your dog has a cancer diagnosis does not mean that euthanasia is on the immediate horizon.

However, there will come a time when it really is likely the most humane thing that you can do for your dog.

The following is a list of signs that it might be time to end your dog’s life:

  • Significant decrease in appetite or refusal to eat anything at all
  • Quick weight loss
  • Persistent diarrhea or vomiting
  • Limping or lameness that does not appear to be getting better
  • Changes in breathing patterns
  • A lack of interest in things your dog used to love or a general lethargy
  • Apparent difficulty moving around or slowing down
  • Any quick and significant change in your dog’s daily habits.

There are many dogs who can continue to be happy and comfortable even with a cancer diagnosis.

If your dog still seems to be happy and does not display any of the common signs of a dog in pain, it is probably not time to euthanize him just yet.

You want to have as much quality time with your dog as possible.

However, the key is QUALITY time.

If you see that your dog is suffering so much that there is no quality left, it really might be time to make the hardest decision and euthanize him.

However, this is something that you should talk about with your vet, as your vet has a much better understanding of exactly what may be going on inside your dog’s body.


At the end of the day, it is going to be your decision when to decide to let your dog go.

In many cases, it is going to come down to what you know is right.

If you know that your dog has a cancer diagnosis but see that he is still enjoying life and functioning well, you can focus on maximizing his quality of life for as long as possible.

However, if you see that he has no quality of life left and is experiencing nothing but pain and suffering, it is probably time for you to let your best friend go.

When you make the decision to euthanize your dog, you may feel significant guilt afterwards.

You might wonder if you should have waited a bit longer or if there could have been some chance of a cure if you had just given it more time.

This is completely normal, but the truth is that euthanizing your dog is the most selfless thing you could possibly do for your best friend.

You are releasing him from his pain and allowing him to cross the Rainbow Bridge, even though it is going to break your heart.

It is the ultimate sacrifice and one final act of love for your dog.

Sharing is caring!

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

National Canine Research Association of America