Cancer Surgery for Dogs and Cats in Boston

A cancer diagnosis is scary. Knowing what surgery can do helps you make the best decision for your pet.

Our board-certified surgeons have the training, imaging, and reconstructive skill to give your pet the best chance at a good outcome.

What Should I Know About Cancer Surgery for My Dog or Cat?

Cancer surgery in pets isn’t just about removing a lump. The goal is to remove the entire tumor with clean margins, meaning no cancer cells are left behind at the edges of the tissue that was taken out. This is one of the most important factors in whether a tumor comes back.

Getting clean margins sounds straightforward, but it requires careful planning. The surgeon has to determine how much tissue to remove around the tumor, how to approach it without disrupting important structures, and how to close the wound afterward, especially when the tumor is large or in a difficult location. This is where board-certified surgical training makes the biggest difference. A specialist plans the surgery around the margins, not just the visible mass.

Before surgery, it’s also important to understand whether the cancer has spread. Some cancers have very good outcomes with surgery, especially when caught early and removed completely. Others are more complex, and surgery may be one part of a larger treatment plan. In some cases, surgery may not be curative but can still significantly improve your pet’s comfort and quality of life by removing a mass that’s causing pain, difficulty breathing, or trouble eating. Our surgeons will be direct with you about what surgery can and can’t accomplish for your pet’s specific diagnosis, so you can make the best decision for your family.

Common Cancer Surgeries We Perform

CORE performs a wide range of cancer surgeries in dogs and cats. These are the conditions we see most often.

Skin and Soft Tissue Tumors Mast cell tumors, soft tissue sarcomas, and large lipomas are among the most common tumors we remove. Many are curable with surgery alone when caught early and removed with clean margins. These tumors often require wider excision than owners expect because the surgeon needs to take a margin of healthy tissue around the visible mass to make sure no cancer cells are left behind. That’s where a surgeon’s planning makes the difference between a tumor that’s gone for good and one that comes back.

Mammary Tumors Mammary tumors are common in unspayed or late-spayed female dogs and cats. Surgery is the primary treatment and can range from removing a single mass to removing an entire mammary chain depending on the type, size, and number of tumors. Early removal gives the best prognosis, especially when margins are clean and the cancer hasn’t spread to lymph nodes.

Oral Tumors Tumors in the mouth can affect your pet’s ability to eat, breathe, and live comfortably. Surgery often involves removing a portion of the jaw (mandibulectomy or maxillectomy), which sounds frightening, but dogs and cats adapt remarkably well and most eat normally afterward. The key is catching these tumors early. If you notice a growth in your pet’s mouth, changes in eating habits, drooling, or facial swelling, have it evaluated promptly.

Tumors Requiring Reconstructive Surgery When a tumor is large or located in an area where there isn’t much surrounding tissue, removing it completely can leave a wound that won’t close with simple stitching. This is where reconstructive techniques come in. Our surgeons are trained in advanced closure methods, including skin flaps and grafts, that allow them to remove the full tumor while rebuilding the area so it heals properly. This means your pet doesn’t have to compromise on tumor removal just because the location is challenging.

Other Cancer Surgeries We Perform

  • Injection-site sarcomas (feline injection-site sarcoma, or FISS) in cats
  • Liver tumors
  • Bone cancer (osteosarcoma), which often requires amputation Learn more about amputation surgery
  • Bladder tumors (transitional cell carcinoma/TCC)
  • Lung tumors (pulmonary masses)
  • Thyroid tumors
  • Lymph node biopsy and removal for cancer staging
  • Anal sac tumors (apocrine gland adenocarcinoma)

What to Expect for Your Pet’s Cancer Surgery at CORE

Your consultation starts with a thorough exam and review of everything that’s been done so far: biopsy results, imaging, bloodwork, and any input from your primary vet or oncologist. If additional staging is needed, such as CT imaging or lymph node evaluation, we can perform that at CORE. Your surgeon will walk you through the diagnosis, explain the surgical plan, discuss what clean margins look like for your pet’s specific tumor, and give you an honest assessment of prognosis and recovery. You’ll receive a detailed estimate before surgery, and our team is happy to work with your pet insurance provider.

Recovery from most cancer surgeries takes 10 to 14 days, with restricted activity and incision monitoring. Some procedures, particularly those involving reconstructive closure, may need a bit more time and attention during healing. You’ll go home with clear instructions and can call us anytime.

After surgery, the removed tissue is sent to a pathologist for analysis to confirm whether margins are clean. Your surgeon will explain the results and what they mean for your pet’s outlook, including whether additional treatment is recommended.

“Dr. Davis is extremely knowledgeable and professional. She really cares about my dog and explained everything about my dog’s tumor in English. I was really upset and worried about my best friend and she made me feel comfortable about having her as his surgeon. Dr. Davis is so much better than the corporate vet clinics. Thank you.” – Laura H.

Frequently Asked Questions

I found a lump on my dog or cat. What should I do?

Have it evaluated by your veterinarian as soon as you can. Not every lump is cancer. Many masses turn out to be benign, like lipomas or cysts, that may not need treatment at all. But the only way to know for sure is to test it. Your vet can perform a fine needle aspirate or biopsy to determine what the lump is, and if surgery is recommended, a referral to a board-certified surgeon ensures the best chance at complete removal, whether the mass is benign or malignant.

Does my dog’s or cat’s tumor need surgery?

Not every tumor requires surgery, but many benefit from it, especially when the tumor is growing, in a location that affects your pet’s comfort or function, or has been identified as a type that’s likely to spread. Our surgeons will review your pet’s biopsy and imaging and give you an honest recommendation about whether surgery is the right next step.

What are “clean margins” and why do they matter?

Clean margins mean the surgeon removed enough tissue around the tumor that no cancer cells are found at the edges of what was taken out. This is the strongest indicator that the tumor has been fully removed and is less likely to grow back. Achieving clean margins requires careful surgical planning, which is why this type of surgery benefits from a board-certified surgeon’s training.

What happens if the margins aren’t clean?

It depends on the tumor type and location. In some cases, a second surgery (revision) can remove the remaining affected tissue. In others, radiation therapy may be recommended to treat the area. For certain low-grade tumors, close monitoring may be appropriate. Your surgeon will explain the options specific to your pet’s situation and work with your oncologist if additional treatment is needed.

How do you know if the cancer has spread?

Staging is the process of evaluating whether cancer has moved beyond the original tumor. This may include CT imaging to look for spread to other organs, lymph node evaluation (biopsy or removal), and bloodwork. Our surgeons coordinate staging before surgery so the full picture is clear before we operate.

Will my pet need chemotherapy or radiation after surgery?

That depends on the type of cancer, the margin results, and whether there’s evidence of spread. Our surgeons will discuss this with you after surgery and can coordinate with your pet’s oncologist to determine the best next steps. For many tumors, surgery alone is curative. For others, additional treatment improves long-term outcomes.

How long can a dog or cat live after tumor removal?

This varies widely depending on the type of cancer, how early it was caught, whether margins were clean, and whether the cancer has spread. Some pets live years after tumor removal with no recurrence. Our surgeons will give you an honest, specific prognosis based on your pet’s diagnosis rather than a generic answer.

What is reconstructive surgery, and when is it needed?

Reconstructive surgery is used when removing a tumor leaves a wound too large to close with simple stitching. Our surgeons use techniques like skin flaps and grafts to rebuild the area, allowing for complete tumor removal even in challenging locations. This is especially common with large skin tumors, tumors on the face or limbs, and cases where wide margins are needed.

How much does cancer surgery cost for a dog or cat?

Cost varies depending on the type and location of the tumor, the complexity of the procedure, and whether additional diagnostics or reconstructive techniques are needed. We provide a detailed estimate before surgery so there are no surprises, and we’re happy to work with your pet insurance provider.

Can I get a second opinion at CORE?

Absolutely. If your pet has been diagnosed with cancer and you’d like another perspective on the recommended treatment plan, our surgeons welcome second opinion consultations. We’ll review your pet’s records, imaging, and biopsy results and give you our honest assessment.

Schedule Your Consultation

If your pet has been diagnosed with cancer or your veterinarian has found a mass that needs evaluation, your consultation includes a complete exam, staging review, and honest guidance about what surgery can accomplish.

CORE Veterinary Surgical Clinic provides cancer surgery and advanced surgical care for dogs and cats across Greater Boston.