My Pet Has Cancer — Where Do We Go From Here? 2 Vets Explain What Comes Next

Having lost two dogs to cancer in the last year, I feel as though my eyes have been opened to the world of veterinary oncology. Trust me when I say that before this, cancer in dogs and cats was not even on my radar.

I distinctly remember the first time I walked into our vet's office post-diagnosis with my chocolate Labrador, Bill. After I asked her if this was all somehow a mistake, the next words out of my mouth through tears were: OK, so what's the game plan? My husband and I knew we wanted to attack Bill's cancer head-on, and we were presented with options based on what we were able to realistically commit to emotionally, financially, and logistically.

Here's what to expect as your best friend prepares to start treatment — including why you're not going to be able to keep them company like you might with a human — from two practicing veterinary oncologists.

What types of treatment can my pet get for cancer?

Veterinary oncologist Dr. Jack O'Day says that if your dog or cat has cancer, there are three modalities commonly used for treatment: chemotherapy, radiation, and surgery.

Chemotherapy

When dogs are given chemo, it can be oral or injectable. When given orally, O'Day says it's as simple as giving a pill. When it comes to injectable chemo, the drug is administered through an intravenous, or IV, line and can be quick or more drawn out, with some over the course of 20 to 30 minutes and, in very rare cases, over the course of hours.

"I think it's hard for people to imagine what's happening behind the scenes," says Dr. Daniela Korec, a Virginia-based practitioner. "Those oral chemos are often given with snacks — it's actually the way that these dogs are getting chemo sometimes. For the infusions, they have at least two or three people tending to them while they're getting the infusions."

Radiation

Radiation is used for different types of tumors and in specific scenarios like pre or post-operation.

"One thing that's really unique to veterinary radiation that's super different from radiation for people is that our patients have to be anesthetized," Korec says, adding that pet parents are typically very surprised by this, but it's because you can't communicate things like "don't move" or "breathe in" to an animal.

Surgery

Animals that are the best candidates for surgery will have non-metastatic, or non-spreading, cancer.

"We have the ability to do treatments and intense surgeries that people might be really worried about at the beginning — like an amputation — that our four-legged friends tolerate so well," explains Korec, adding that surgery is a very beneficial tool for some bone cancers, like osteosarcoma. "We can often put our feelings on them for (something like) an amputation, and it's just not the same."

How will I know what type of treatment my dog will get?

Short answer: Every single type of cancer in pets will have a different method of treatment.

"Surgery and radiation are going to be your local therapies – taking a tumor off or pointing radiation at a tumor – and then chemotherapy kicks in when we're worried about spread," explains Korec. "Chemo can work on a local tumor, but we're really worried about all those little cells traveling through the body, so we're trying to slow down, prevent, or extend the time before relapse."

How big of a time commitment is cancer treatment for my pet going to be?

O'Day says chemotherapy treatment is most commonly once a week or once every three weeks.

"Our goal is to make sure that you're spending the most time with your pet, so a lot of these appointments can be less than an hour or about an hour because, at the end of the day, we're doing this to maintain a normal lifestyle and high quality of life," Korec says. "For a lot of owners, the whole point is to spend that time with their pet."

Are there any other types of treatment we can try? And what about immunotherapy?

While immunotherapy is not as common in veterinary medicine as in human medicine, O'Day says he is seeing it more and more commonly.

"We also have other modalities like electrochemotherapy that we use, which is using electrical pulses in addition to chemotherapy to try to mimic radiation in some ways," he says. "So there are a lot of options, and it's always going to be tailored specifically to the patient."

When my relative was sick, I got to sit with them during chemo and keep them company. Can I do that with my pet?

Unfortunately, no. The reasoning is simple: It's against the law.

"There is a set of rules that govern how hazardous drugs are administered in the United States," O'Day explains. "So because of that, owners cannot be with their pets while the actual drug is being administered."

The secondary reasoning may surprise you — it minimizes stress in your pet when you're not present. "It can be a stressful event for (pets) to see their owner and not be able to interact with them," O'Day says of pets undergoing treatment.

Will my pet lose their hair?

In most cases, no. But some breeds, like doodles and golden retrievers, are prone to hair loss from cancer-fighting modalities, and some cats may lose their whiskers. "I try to remind my pet owners that pets don't care about their hair," says Korec. "It's not painful, and it's typically not itchy."

How much is this going to cost?

The cost of treating cancer in pets varies by what type of treatment your pet is getting, your pet's size, and what area of the country you live in.

According to a 2023 study done by CareCredit, a credit card that can be used for health expenses and paid off over time, the average cost of treatment for a dog diagnosed with lymphoma is $5,351, and for cats, $3,980.

I am choosing not to treat. Am I the worst person in the world?

Absolutely not. Korec says she reminds her clients that there is no shame or guilt in choosing palliative care over chemotherapy or radiation.

"Sometimes the kindest thing you can do is not to treat, "says Korec. "We balance risk versus benefit all the time, and there are cases where the risk is not worth the potential benefit. I can do a lot of things, but if it doesn't improve the quality of life, I think stepping away and focusing on palliative care is exactly what you would want to do."

Adds O'Day, "Huge parts of our caseload are not actually using true anti-cancer therapies, like surgery and radiation, but focusing on comfort care and using a lot of different strategies to keep patients as comfortable as we can for as long as we can."