Subcutaneous Lumps in Cats

Researched by

The Vetster Editorial Team

Verified by

Dr. Jo Myers

Published on Sep 16, 2022

Last updated on Apr 7, 2024

3 min read

Symptom

Cat

Published on Sep 16, 2022

Last updated on Apr 7, 2024

3 min read

Key takeaways

Subcutaneous lumps are masses, lumps, or bumps found under the skin, rather than within the skin or at the surface of the skin; the overlying skin moves freely over these lumps and they do not arise from bone.

Subcutaneous lumps can be anything from a foreign body, parasite, hernia, injury or infection, to a tumor or a cancer such as feline injection site sarcomas
Many types of subcutaneous lumps are not a threat to overall health, but some are
There may be no additional clinical signs associated with a subcutaneous lump, but in some cases, cats may experience localized pain, swelling, redness, excessive licking, rash, or or oozing of the skin overlying the affected area
Diagnostic testing such as aspiration, biopsy, and cytology is necessary to confirm the cause of the subcutaneous lump
Generalizing outcomes is difficult due to the variety of underlying causes

Concerned with Subcutaneous Lumps in Cats?

Chat with our licensed vet techs in the app to learn more and have your questions answered.

A closer look: Subcutaneous Lumps in Cats

Subcutaneous lumps in cats are very common. While many subcutaneous lumps are not necessarily cause for concern, some are serious and potentially life-threatening. Diagnostic testing is necessary to determine the specific type of lump, and timely intervention is critical for a good outcome, if the lump proves to be serious.

Connect with a vet to get more information

With verified licenses and excellent reviews from pet parents like you for this type of symptom

Possible causes

Subcutaneous lumps have many causes, including

Scar tissue

Injuries

Skin Abscesses in Cats Botflies (Cuterebriasis) in Cats Grass Awn Migration (Foxtails) in Cats Hernias in Cats Fatty Tissue Tumors (Lipomas) in Cats Mast Cell Tumor (Mastocytoma) in Cats Mammary Gland Tumors in Cats Injection Site Sarcoma in Cats

Lipomas (fatty tumors) are an example of a very common benign subcutaneous tumor. Mammary adenocarcinoma (breast cancer) is a common subcutaneous malignancy, particularly in intact female cats and females who experienced at least one heat cycle prior to being spayed.

Feline injection site sarcomas (FISS) are a serious concern for subcutaneous masses at injection sites.

Risk factors

There are a wide range of possible causes for a subcutaneous lump on a cat. Some particular types of lumps are more or less likely depending on their location and the age of the cat. Treatment varies depending on the diagnosis.

Testing and diagnosis

The physical appearance of the lump sometimes suggests certain diagnoses, but analysis of the cells within the lump is necessary to confirm a diagnosis. Common diagnostic approaches include:

Aspiration (the use of a needle to non-invasively draw out material from inside the subcutaneous lump for testing)
Cytology (the microscopic investigation of the material to determine its structure, function and pathology)
Biopsy Treatment is dependent on diagnosis. Some subcutaneous lumps are harmless when left in place and some must be removed. In some cases, outcomes are more severe such as with fibrosarcoma.

Similar symptoms

Subcutaneous lumps may be mistaken for:

Cutaneous lumps (distinguished from subcutaneous lumps by the fact that they mark or disrupt the surface of the skin)
Tumors arising from the bone

Associated symptoms

A variety of symptoms occur depending on the cause of the subcutaneous lump. If the lump is associated with an underlying condition, the symptoms of that condition are expected to develop without treatment. If the lump is benign, there may be no additional symptoms other than the lump itself.

Examples of symptoms associated with subcutaneous lumps include

Localized pain

Swelling

Rash in Cats Itching and Scratching (Pruritus) in Cats

Oozing skin