You were giving your dog a belly rub or brushing your cat when your fingers found something unexpected — a bump, a lump, or a firm mass just beneath the skin. Your heart sank. Is it cancer? How long has it been there? Should you rush to the vet?

First, take a breath. Finding a lump on your pet is one of the most common reasons pet owners visit the vet, and the good news is that many lumps turn out to be completely benign. However, some masses do require prompt attention, and knowing the difference can make all the difference in your pet’s outcome.

Whether your veterinarian has recommended surgical removal or you want answers about a new growth, this guide covers the types of skin masses in dogs and cats, when to be concerned, what removal looks like, and why veterinary surgeons and a dedicated oncology team under one roof matters.

Common Types of Skin Masses in Dogs and Cats

Skin masses come in many forms, and each type has its own behavior and level of concern. Here are the most common growths veterinarians encounter:

• Lipomas (Fatty Tumors): Lipomas are among the most frequently diagnosed lumps on dogs, particularly in middle-aged and older pets. These soft, movable masses beneath the skin are composed of fat cells and are almost always benign. They rarely require removal unless they interfere with movement, but any new lump should be evaluated to confirm the diagnosis.
• Mast Cell Tumors: Mast cell tumors are one of the most common malignant skin tumors in dogs. They can be deceptive — sometimes appearing as a small bump resembling a bug bite. They range from low-grade to high-grade, with aggressive forms capable of spreading to lymph nodes, liver, and spleen. Every mast cell tumor should be taken seriously.
• Histiocytomas: These small, red, button-like growths are most common in young dogs under three years of age. They are benign immune cell tumors that often appear suddenly but typically resolve on their own within two to three months. Your veterinarian may recommend monitoring rather than removal.
• Sebaceous Cysts and Adenomas: Sebaceous cysts form when oil glands become blocked, creating a fluid-filled sac. Sebaceous adenomas are small, wart-like growths from the same glands. Both are benign and common in older dogs but may need removal if they rupture or become infected.
• Fibrosarcomas: Fibrosarcomas are malignant tumors arising from connective tissue, particularly notable in cats where they can develop at injection sites. These locally aggressive tumors invade deep into surrounding tissue and require wide surgical margins. Early detection is critical.

When Should You Be Concerned About a Lump?

While not every lump is an emergency, certain characteristics warrant a prompt veterinary evaluation. Watch for these warning signs:

• Rapid growth: A mass that doubles in size within a few weeks is more likely to be problematic than one that has remained stable for months.
• Firmness and irregular shape: Benign lumps like lipomas tend to be soft and round. Masses that feel firm, fixed to underlying tissue, or have irregular borders deserve closer inspection.
• Ulceration or bleeding: Any mass that breaks through the skin surface, bleeds, or develops an open sore should be evaluated promptly.
• Location concerns: Masses near joints, in the mouth, on the digits, or in areas where they restrict movement may need earlier intervention regardless of their type.
• Your pet’s behavior: If your dog or cat is scratching, licking, or biting at the lump, or if it seems painful when touched, this could indicate irritation, infection, or a more aggressive growth.

As a general rule, any new lump should be examined by your veterinarian. Even if benign, documenting the mass helps your team monitor for changes over time.

Why Early Removal Matters

One of the most important messages in veterinary oncology and surgery is this: when it comes to mass removal, earlier is almost always better. Here’s why:

• Clean margins are easier to achieve on smaller masses. When a surgeon removes a tumor, the goal is to excise it along with a margin of healthy tissue — achieving “clean” margins means no cancer cells remain at the edges. The smaller the mass, the easier it is to take adequate margins without complex reconstructive techniques.
• Staging is more favorable. Smaller tumors are less likely to have spread to lymph nodes or distant organs. Removing a mass while it is still localized gives your pet the best chance at a complete cure.
• Less invasive surgery. Smaller masses mean shorter procedures, smaller incisions, and faster recovery. Waiting may require more extensive surgery or reconstruction that could have been avoided.

If your veterinarian has recommended mass removal, don’t delay. The waiting game rarely works in your pet’s favor with potentially cancerous growths.

The Mass Removal Process at Dogwood

At Dogwood Veterinary Specialty and Emergency, our approach to skin mass removal is thorough, methodical, and tailored to each patient. Here is what you can expect:

• Step 1: Diagnosis. Before any surgery, we need to know what we’re dealing with. This often begins with a fine needle aspirate (FNA), a quick procedure where a small needle collects cells from the mass for microscopic evaluation. For masses difficult to characterize with FNA, an incisional or excisional biopsy may be recommended.
• Step 2: Surgical Planning. Once we have a diagnosis, our veterinary surgeons develop a customized surgical plan — determining margin width, planning the incision, and considering the mass’s location relative to critical structures. For complex cases, advanced imaging such as CT scans may be used.
• Step 3: Wide Margin Excision. Our veterinary surgeons perform wide margin excision, removing the mass with a surrounding border of healthy tissue. The margin width depends on the tumor type — mast cell tumors, for example, typically require two-centimeter lateral margins and one fascial plane deep. This precision significantly reduces the chance of local recurrence.
• Step 4: Histopathology. Every removed mass is submitted for histopathology. A veterinary pathologist examines the tissue to confirm the tumor type, grade, and margin status — providing critical information about prognosis and whether additional treatment is needed.

When Oncology Gets Involved

Sometimes pathology reveals a mass is more aggressive than expected, or that cancer cells remain at the surgical margins. This is where having a veterinary oncology team in the same hospital becomes invaluable.

At Dogwood, our oncology department works hand-in-hand with our surgical team. If histopathology results indicate aggressive cancer, a high-grade tumor, or incomplete margins, your case is seamlessly referred to our oncologists — without you needing to leave the building.

Our veterinary oncologists can recommend and administer a range of treatments depending on your pet’s specific diagnosis:

• Chemotherapy: Chemotherapy in animals is generally well-tolerated with fewer side effects than in human medicine. Protocols are tailored to the tumor type and your pet’s health.
• Radiation therapy referral: Our oncology team coordinates referrals to trusted radiation centers and manages your pet’s care throughout the process.
• Ongoing monitoring: Regular rechecks, imaging, and bloodwork catch any recurrence or spread early for the best long-term outcome.

This in-house approach means no gaps in communication, no lost records, and no delays in starting treatment. Your pet’s surgical and oncology teams work together under one roof.

Recovery After Mass Removal Surgery

Most pets recover well from mass removal surgery, especially when the mass is caught early. Here is what to expect during recovery:

• Incision care: Keep the surgical site clean and dry. Your veterinary team will provide specific instructions, but in general, avoid bathing your pet or allowing them to swim until the incision has fully healed.
• E-collar: Your pet will need to wear an Elizabethan collar to prevent licking or chewing at the incision. It is essential for preventing infection and proper healing.
• Activity restriction: Limit exercise for 10 to 14 days — leash walks only for dogs, and cats should stay in a quiet room. Avoid jumping, running, and rough play.
• Suture removal: External sutures are typically removed 10 to 14 days after surgery. Some surgeons use absorbable sutures. Your discharge instructions will specify which type was used.
• Follow-up appointment: A post-operative recheck ensures proper healing and is when your team reviews histopathology results and discusses next steps.

Found a Lump? Let’s Get Answers

If you’ve found a lump, bump, or growth on your dog or cat, don’t wait and wonder. Early evaluation and treatment give your pet the best chance for a positive outcome, and at Dogwood Veterinary Specialty and Emergency, we have everything your pet needs under one roof.

Our veterinary surgeons specialize in soft tissue surgery with the goal of clean margins and minimal impact on quality of life. If oncology care is needed, our dedicated team is right here — ready to step in without delay.

Call our team at (404) 609-1234 to schedule a surgical consultation. Contact Dogwood Veterinary Specialty and Emergency or ask your primary care veterinarian for a referral. Serving Marietta, East Cobb, Kennesaw, Roswell, Smyrna, and the greater Cobb County area.

Visit us online at www.dogwood.vet to learn more about our surgical and oncology services.