Lumps and Bumps – What Is This Mass on My Pet?

Have you ever been caught off guard by a lump or bump on your four-legged companion that you are sure was not there a few days ago? If so, is it serious? The short answer – possibly.

Lumps and bumps, also called masses, can develop quickly on our beloved companions, especially as they reach their golden years. When a mass is discovered, veterinarians recommend applying the “1-2-3 Rule” to determine if a mass should be checked.

  1. Has the mass been present for over a month?
  2. Has the mass doubled in size since it was discovered?
  3. Is the mass 3 cm or larger in diameter?

If the answer is yes to ANY of these questions, then the mass should be examined by your veterinarian.

On exam, the veterinarian will palpate or feel the lump to determine its size, texture, firmness, what tissue is it originating from, and if it is causing any discomfort or issues. While veterinarians determine a lot about the nature of a thorough mass examination, a diagnostic tool such as fine needle aspirate or biopsy is needed to identify what type of mass it is.

Generally, a fine needle aspirate is recommended as a first-line tool to make a diagnosis of a mass. With this procedure, the mass is isolated, and a needle is used to collect a small sample of the individual cells that make up the mass. Once the cells are collected, they are sprayed onto a microscope slide to dry. The sample is then processed with special stains to make the cells more easily identified under the microscope. A diagnosis is made based on the types of the cell identified under the microscope. A fine needle aspirate is easily performed, non-invasive, causes very little pain or discomfort, relatively inexpensive, and gives an answer quickly (minutes to hours, depending on the laboratory’s capabilities). However, there are some types of masses that do not give adequate samples to make a diagnosis with aspirate and require a biopsy as then next step.

When a biopsy is performed, heavy sedation or anesthesia is required. The mass may be completely removed by surgical excision, or the veterinarian may recommend taking a sample and awaiting results before removing the mass completely. When a sample is obtained, it is submitted to a processing laboratory, which is generally off-site. The tissue is processed in chemicals and stains, which makes it easier to identify cells. The tissue is placed in wax and then sliced very thin so it can be examined under the microscope by a pathologist. The process of obtaining a biopsy sample is more invasive and more costly, and results are not reported as quickly (days to weeks). However, biopsy allows a larger sample to be examined to make the most accurate diagnosis possible.

Just like every pet, each lump and bump is different and carries its own particular treatment recommendations and prognosis. Based on diagnosis from fine-needle aspiration or biopsy, the veterinarian will guide you through the process and help you decide on the best course of care for your companion.

When it comes to lumps and bumps, the best advice is that when in doubt, get it checked out, sooner rather than later!

If you have any questions, give us a call at 403-948-2733.

Written by: Dr. Peyton Ware