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Dog Cancer - Understanding Cancer Diagnosis and Treatment in Dogs

Is cancer in dogs common?

Yes, cancer in any older mammal is common. Cancer is when we have cells dividing over and over again with no control. We have genes and genetics that help our body realize when a cell is dividing inappropriately early. Cells are only supposed to divide a certain amount of times before they stop, die off, and are replaced with new cells. Cancer is when we have cells that are not doing that. We all, as animals, have cells in our body that are there to monitor and they're there to program these cells to die. That's why we don't have a lot of young dogs or young animals with cancer. It's not to say that it can't happen. However, it is much more common in middle to older age dogs. We also see dogs of all ages and we definitely have a population of senior dogs that we see and of those senior dogs, it is more common to see cancer than not.

Dr. Meghan Denney
Four Paws At Fulshear

What are the common types of cancer in dogs?

The most common types of cancers that I've seen are skin cancers, like squamous cell carcinoma. We can see some benign neoplasia. Cancer and neoplasia are the same thing, but you can have benign growths, and we see a lot of benign fatty tumors. We can also see melanomas, especially in our black dogs and their black nails, they're a little more prone to it. We see hemangiosarcoma, which is something that can happen in the spleens of dogs. With patients that are five years old or older, especially our larger breed dogs, our veterinary technicians will recommend a senior sneak peek at their annual exams, which involves an ultrasound probe on their belly. We're looking at the five major organs. We're not radiologists, so we might not see something subtle, but if there is a tumor in there, it's like early cancer detection. There's something that we can do, especially our splenic masses or our spleen tumors. We don't need a spleen to survive, neither do dogs or cats, so we're able to actually remove it, and that buys time. We're also able to send that off to the lab and figure out what type of cancer it is. Those are probably the most common. Sarcomas arise from muscle cells, but we can get tumors on the skin, on the tissues underneath the skin, and of any organ. There's lung cancer, bladder cancer, liver cancer, and gallbladder cancer. Any organ that makes up your body has a possibility to develop cancer; eyes, mouth, bones, you name it.

What are some signs and symptoms of dog cancer?

Dogs and cats are really good at hiding their illnesses. However, some subtle symptoms might include a lessened appetite, sleeping more, not eating, maybe drinking more, and lethargy. In really serious cases, you can see vomiting, collapse, and even, unfortunately, sudden death. This is why preventative medicine is so important. We are trying to catch these cancers when they might be treatable so we can help your pet to live longer and have a better quality of life.

How will a veterinarian diagnose cancer in a dog?

We can get a diagnosis through a couple different methods. With lab work, sometimes we can get an inkling with elevated calcium values. That can be a sign that there's cancer lurking somewhere. We can see cancer cells in the urinalysis, so we can get a diagnosis off of an ultrasound, off of x-rays, and off of a biopsy. We can even get a diagnosis on skin tumors that we've put a little needle in and done a fine needle aspirate. We look at the cells right here in the clinic. I can usually tell if I think that this is more malignant or more benign. Usually, if the cells that I'm seeing really don't look great, I send it off to a pathologist to confirm and help us make a diagnosis. We rely on physical exams, diagnostic testing, and diagnostic imaging to get a diagnosis of what we're dealing with, which not only helps us know what's going on, but it also helps me tell you what's the prognosis, possible treatments, and mean survival time.

What treatment options are available for dogs with cancer and what are some possible side effects?

There is oncology for dogs. Just like we have oncologists for humans, there are oncology veterinarians for dogs. They are board specialists. There is chemo, just like there is in humans. The biggest difference in dogs and cats is that we're not going for a cure. We're going for remission and quality of life, so we are not giving the same doses of chemo that humans get, and we are not trying to cure our animals because they just don't live long enough. That being said, we don't see as many side effects in our pets as we do in humans. If you've had a family member that has passed away from cancer and has gone through chemo, they look like they've been through hell. It's horrible. We are not doing that to the pets. That's not the goal.

There is also radiation therapy which can have some localized side effects with some skin irritation. And then surgery, there are a lot of cases we can go in and cut it out. And that might be completely curative in some cases. We also have a new tool available to us, the Onco9. That is an actual blood test. It's a screening tool. We get a sample of blood from your dog, we send it off to the lab, and within 14 days, we'll get an answer that says cancer yes, cancer no. They've learned how to check for certain cancer markers in the blood. A percentage of them will be able to get identified by that test, but most of them won't. It is mainly a screening tool that we use, much like in humans.

If you still have other questions and you'd like to reach out to us, you can call us directly at (281) 801-1444, or you can email us at [email protected]. But please do reach out, and we'll get back to you as fast as we can. Don't forget to follow us on social media Facebook, Instagram

Dog Cancer - FAQs

Dr. Meghan Denney
Four Paws At Fulshear

What should I do if my dog gets diagnosed with cancer?

It can be a difficult topic for many pet owners, and understandably so. It's important to understand what the diagnosis means. This not only confirms that your pet has cancer but also identifies the type of cancer. We can see evidence of cancer like a mass or bone tumor on x-rays, but we also need to determine the type. This is often based on our diagnostic imaging and sometimes requires a biopsy. Once we have a presumptive diagnosis of cancer, we discuss the most common kinds and how they behave, their timeline, whether they spread, symptoms, and possible treatment options. If we have a confirmed diagnosis through biopsy, we begin cancer staging to see if it has spread elsewhere in the body, similar to humans. This can involve an abdominal ultrasound and chest x-rays.

If the cancer is at stage four and spread to multiple organs, we may not pursue treatment and instead consider humane euthanasia. However, if it's a skin tumor, for example, we might use medication to shrink it and then remove it through surgery. If you are interested in a full workup once we've done as much as we can, we can refer you to veterinary oncology. We refer to Sugar Land Veterinary Specialty Hospital, quite frequently, along with Gulf Coast and Texas A&M Veterinary School, the teaching hospital. Oncology consults are an option as they have more information because that is all they do. They deal with cancer. It's kind of like if you go to a dermatologist and you get diagnosed with a melanoma, they might send you to a surgeon who's going to send you to an oncologist. I've got a very broad understanding of everything, and veterinarians do a little bit of everything, so I will be able to walk you through those steps. If we decide to pursue tertiary care/referral with oncology, then I can facilitate that.

What is the cure rate of dogs with cancer?

It depends on the type of cancer. For instance, a small skin tumor has a high likelihood of being 100% curative through surgery. However, other types of cancer that have spread to other parts of the body may only buy time through radiation and chemo but ultimately, the pet will succumb to their disease. It's very dog-specific and depends on the individual. It's also important to consider the financial aspect of treatment and the quality of life of the pet. This is a conversation that's best had in person or over the phone to discuss what's individually going on with your pet and the options available. This kind of stuff is really hard, and it's really emotional because our pets are part of our families. When we're having these conversations, I prefer for them to be in the clinic. I hope this gives you a good foundation, but if we are considering going through this, please make an appointment or if you haven't already, call me and let's do a phone consultation and walk through this together.

Is a dog cancer diagnosis a death sentence?

Every cancer is different. Some are more curable than others. However, stage four tumors that have spread throughout the body and cause the patient to feel awful typically won't live for very long, and we may decide to say goodbye a bit sooner. It's important to ensure our pets don't suffer, even if it means making the difficult decision to let them go. This is a very emotional process, but we're here to support you through it.

If you still have other questions and you'd like to reach out to us, you can call us directly at (281) 801-1444, or you can email us at [email protected]. But please do reach out, and we'll get back to you as fast as we can. Don't forget to follow us on social media Facebook, Instagram


At Four Paws at Fulshear Veterinary Clinic, we know how important early cancer detection can be when it comes to your dog's health. We now offer OncoK9, an early detection cancer screening done as a liquid biopsy test from a simple blood draw to detect abnormal DNA that is released by cancer cells into circulation. 

We are the only clinic currently on this side of Houston, TX to offer OncoK9. Learn more directly at OncoK9 by clicking here.

OncoK9 Early Cancer Detection Dogs

OncoK9 Recommended Screening Dog Cancer

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