What to expect with lump removal surgery


A lump has been located on your pet and we have recommended surgery as part of the treatment plan. 

The goals of surgery are to:

  1. Surgically remove the lump to reach a cure; or
  2. Remove all visible lump; or
  3. Identify the mass to determine a treatment plan; or
  4. Form part of a multimodal approach along with radiation or chemotherapy.

Factors that affect the ability to achieve a cure

Tumor type

Tumor behavior

Tumor Location

Surgery preparation

Sometime during your pet's life, surgery may be indicated whether it be for lump removal, desexing, a dental, or due to illness. No matter what the reason, there are always risks associated with general anesthesia or surgery, so good preparation is important to help reduce the chance of complications.

Pre-surgical preparation involves:

Getting your pet ready for surgery is a simple process but can still be daunting for many pet owners. Here are some guidelines to ensure your pet is ready for their day at the clinic.

No Food

Your pet must have an empty stomach before the scheduled anesthetic. Please do not feed your pet after 10 pm the night before. The water is fine. 


Pets under 3 months of age may be offered a small amount of food on the day of surgery to ensure blood sugar levels are maintained. 


Please take your pet to the toilet prior to admission. This will reduce the chance of soiling themselves during surgery and recovery.


Please avoid swimming or playing in the dirt on the day before surgery. This will help lower the risk of introducing bacteria. Where possible, brush, or bathe your pet beforehand. 


If your pet is currently on medications, please advise us so that we can recommend when to administer them. Some medications such as insulin or heart medications must be maintained. 

Pre-anesthetic blood work

Pre-anesthetic blood work can help us determine if there are any pre-existing illnesses. They test for parameters that are not easily picked up during a physical examination such as anemia, dehydration, liver, or kidney disease. Based on the test results, the anesthetic can be modified to best suit the pet. 

These blood tests check:


Surgery is performed in a sterile manner that helps to protect the normal tissues from tumor cell contamination. We use large surgical drapes, lavage, gloves and instrumental changes were required. The mass is minimally handled to reduce trauma.

Where possible, the lump will be removed in its entirety with clean margins both wide (at least 2 cm margins around the mass) and deep where required.

In cases where this cannot be achieved, the majority of the lump will be removed and samples sent away for pathology to determine the next steps. When suspicious of local lymph node involvement, a biopsy will be recommended.  


Pathology is recommended to help:

Samples of the mass and skin margins can be sent away to an external laboratory. Pathology tests incur additional charges. Unfortunately, not all surgical margins of every mass can be submitted as it takes considerable time and is prohibitively expensive. 

If you agree to pathology, we will advise you of the samples that should be submitted and offer you an estimate before sending the samples away to the laboratory.

Understandably, you may be nervous about surgery for your dog. Here are some of our most frequently asked questions to help put your mind at ease.

Frequently asked questions

What happens during surgery?

Your best friend is in the safest hands. All surgical areas are completely sterile and all lump removal procedures adhere to the highest industry standards. The lump is minimally handled to reduce trauma. 

Where possible, the lump will be removed in its entirety. In cases where this cannot be achieved, the majority of the lump will be removed and samples sent away for pathology to determine the next steps. 

Will the lump grow back?

Some lumps can grow back. As with all lump removal surgery, we recommend you keep a close eye on the area afterward and let us know if you notice any further changes. 

How can we tell if the lump is cancerous?

Samples of the lump and skin margins can be sent away to an external laboratory for further analysis. 

Pathology is recommended to help:

Results are typically received a week later.

What if the lump is malignant?

If you receive the worst news possible - a diagnosis of feline cancer - please take heart in the fact that there are many cancer therapies available today. 

Depending on the type of tumor, a tailored cancer management plan will be discussed with you. With an earlier diagnosis, there is a higher chance of a successful recovery.

Home care

Your pet will be allowed to go home once it has fully recovered from the general anesthesia and its pain is under control. We will notify you when your pet is ready and will provide you with detailed discharge instructions on how to care for your pet at home. Your pet will require rest for the first 10 days and most likely have stitches that will require daily monitoring.