Contributed by:
Howard A. Mintzer DVM
Mid Hudson and Arlington Animal Hospitals
in the beautiful Hudson Valley of New York State

Managing your pet's fatty tumors

We have discovered one or more fatty tumors on your pet. This is not a problem to get alarmed about! Fatty tumors are quite common in middle aged and older pets. Most of the time they are not a problem and the few that become problems can usually be dealt with quite easily if we notice and respond to them at an early stage.

A tumor is a lump of cells that does not obey the normal rules of cell growth. Normally, cells grow until chemical messengers in the body tell them to stop growing. Tumor cells do not listen to these messengers and continue to grow and grow and grow.

Tumors in general may be divided into two types: The first type of tumor is called a benign tumor. Benign tumors usually grow slowly and push other types of cells out of their way. These tumors do not spread to other parts of the body nor do they push their way through nearby organs. The other type of tumor is a malignant tumor. Malignant tumors eat right through nearby organs. Little pieces of these tumors break off and spread to other parts of the body where they grow into new tumors. As you can imagine, a malignant tumor is extremely serious. A malignant tumor is what we refer to as cancer.

The fatty tumor which we have discovered on your pet appears benign. Since it is a benign tumor we are not worried about it spreading to other parts of the body and causing cancer. Most of the time we can leave fatty tumors like this alone. However there are certain circumstances when we must surgically removed them. If any of the following criteria apply, we will need to remove your pet's tumor.

  1. If the tumor is growing rapidly.
  2. If the tumor, after a long period of no growth has suddenly started to grow again.
  3. If the tumor begins to change its appearance, for instance was formerly soft and now is hard or was formerly smooth and circular and now is beginning to grow nodular and lumpy.
  4. If the tumor is beginning to interfere with function. For instance if your pet's tumor is near the elbow joint and is beginning to, or will soon be preventing your pet from moving his elbow.
  5. If the tumor is in a location where any growth will cause it to either be difficult or impossible to remove. For instance, a small tumor on the paw might be able to be removed now. However if it grows larger there might not be enough skin to cover the wound.
  6. If the tumor looks unsightly or upsets you, this is also a reason to have it removed.
  7. If your pet is biting at the tumor and causing it to become infected or bleed.
Hopefully, your pet's tumor does not match any of the above criteria. It is very important that you keeping a close watch on your pet's tumor. Although your pet's tumor is not a problem at this point in time it may become a problem. It is a good idea to write down the size of your pet's tumor using common terms for the size such as pea size or egg size. Each month you should reevaluate the size of the tumor and if any changes have occurred, contact us immediately. We will also evaluate the size and appearance of your pet's growth at each subsequent examination. In that way there will be many eyes watching for changes that will alert us well in advance if surgery becomes necessary.

We all want your pet to live a long, happy, healthy life. With a little extra diligence we will be able to make sure that this tumor does not affect that life. Thank you for caring about your friend!