Fatty tumors are nothing to fear

Happy DogFinding a mysterious growth under your dog’s skin can be a frightening experience; however, owners can find comfort in knowing that these mystery bumps are not as uncommon as they may think.

As dogs age, they can develop benign growths beneath the skin—the most common of these being lipomas, or fatty tumors.

According to Dr. Brandan Wustefeld-Janssens, an assistant professor of surgical oncology at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, lipomas arise from adipose tissue, or fat cells, and are typically found on the chest or abdomen. Some dogs can develop numerous tumors and some can grow very large.

Lipomas are soft, often moveable, and not painful to the touch. While owners may be able to detect the mass beneath their dog’s skin, touch, as a form of detection, should never be used as a diagnostic tool, according to Wustefeld-Janssens.

“If a new growth is found on your dog, making an appointment with your family veterinarian is an appropriate course of action,” he said. “Your veterinarian will likely perform a test called fine needle aspirate to get a sample of the tumor to look at under the microscope.”

This test, however, cannot differentiate between the non-invasive forms of the tumor and the infiltrative form. Infiltrative lipomas do not spread but are known for their penetration into the soft tissues.

“Differentiating between the two tumors is usually done with advanced imaging, like CT scans, or during surgery,” Wustefeld-Janssens added.

After further testing, a veterinarian will be able to diagnose the fatty tumor and assess the need for treatment. In most cases, lipomas are not an immediate cause for worry, and most don’t require surgery.

“Lipomas are mostly asymptomatic unless they are causing compression of a vital structure or become so large that they interfere with mobility. This means that the majority of lipomas do not require surgical removal and are, instead, actively monitored for a change in size,” Wustefeld-Janssens said. “Tumors that we generally treat with surgery are those that arise from deeper areas like the thigh, or if we are suspicious that they are the infiltrative type.”

Although there is very little an owner can do to prevent lipomas from forming, keeping your dog lean and healthy and scheduling yearly check-ups with a veterinarian will allow for early detection of these tumors.

With the guidance and expertise of a veterinarian, discovering a lipoma on your four-legged friend is nothing to fear.

Pet Talk is a service of the Texas A&M College of Veterinary Medicine & Biomedical Sciences. Stories can be viewed on the web. Suggestions for future topics may be directed to editor@cvm.tamu.edu.