Finding a new lump on your dog can be alarming. Some pets just seem to repeatedly develop masses, while such a discovery is unusual with others. So, at what point should you be concerned? There are a number of things to consider.
When Are Lumps Dangerous?
There are no hard-and-fast rules for what constitutes a concerning lump.
Many tumors – including mast cell tumors and melanomas – are called the “great pretenders” because they can look and feel like anything. Even a lesion that looks like a crust or plaque on the skin can actually be a tumor.
It is also true that many dogs will develop benign and fat-based masses (called lipomas) as they age; this is in contrast to people, who usually have some form of metabolic disorder when developing such masses.
Examining & Monitoring Lumps on Dogs
The behavior of the mass is important for you to discuss with your veterinarian. You should ask yourself: Has the mass become red or ulcerated, causing it to bleed? Has the mass gone up and/or down in size, or even disappeared? Has the mass increased in size – and if so, by how much and over what time period?
These are all very important questions that may help a veterinarian decide whether the mass is more worrisome and should be sampled.
Any new or changing lump, big or small, should be examined and potentially re-sampled. Masses can also change over time; a mass that may have been lipoma years ago could manifest as a new tumor over time. Any changes are important and should be communicated with your veterinarian.
Along with your veterinarian, keep a “body map” to track masses. A body map is a piece of paper or digital file that has each mass labeled, measured, and updated routinely. This helps to ensure that all masses are taken care of appropriately.
What About Lumps on Cats?
Cats, unlike dogs, don’t seem to develop masses as commonly. A new mass on a cat, especially in the skin or in areas where previous injections have been given, is concerning and may be a cancerous-type lesion. If any lesion is noted, you should have it investigated by your veterinarian.
Diagnosis and Treatment: What to Expect
Depending on the mass location, size, and potential other factors, a multitude of tests can be performed.
In general, the mainstay and least invasive diagnostic is a fine needle aspirate (FNA) and cytology. This involves placing a needle into the mass and spreading the obtained cells onto a slide for review by a pathologist. If you think of a brick wall, this is like pulling individual bricks out of the wall.
Based on the results of the cytology, some form of biopsy may be indicated. This is more invasive, and typically involves taking a small piece of tissue from within the mass and submitting it for review. Back to our brick wall analogy, this would essentially be evaluating all of the brick and mortar of the entire wall, and may help with a more definitive diagnosis.
If a diagnosis of cancer is made, your veterinarian will perform further tests to ensure it has not spread elsewhere, such as blood work, chest X-rays, or ultrasound of the abdomen.
The bottom line? If you notice a new lump that is growing or has changed in size or consistency, be sure to consult your veterinarian. When masses are small, they are the easiest to remove, and early detection leads to higher rates of control.