A lipoma is a benign fatty tumor. The lumps are composed of fat surrounded by a membrane. Older, overweight female dogs are more prone to developing a lipoma. Dogs that have one lipoma often develop others.

A lipoma appears as a lump under the skin just about anywhere on the body. The lump will be moveable if you press gently, non-painful, and will generally produce no changes in the skin above it. Unless it interferes with movement, a lipoma might not even be noticeable to your dog. 

It is not known how your dog may get a lipoma though, because overweight dogs tend to be more prone to lipomas, obesity may be a factor.

If your dog’s diagnosis was made on the basis of a physical exam only, then the diagnosis is actually only an educated guess. Although a veterinarian may have a lot of experience seeing lumps and bumps, only a biopsy of the lump tissue can provide a definitive diagnosis. Some veterinarians prefer to perform first a fine needle aspirate of the lump in which a tiny needle is inserted into the lump to take a sample for evaluation. An aspirate can be performed without anesthesia and is relatively painless. The problem with fine needle aspirate results is that they can give false readings that do not reflect a true representation of the lump’s characteristics. The only way to make a definitive diagnosis regarding the lump is to have it removed for proper evaluation.

A lipoma may be surgically removed, but unless it interferes with movement, most lipomas are often left untreated.

There is no prevention for lipomas except, perhaps, to keep your dog at an ideal weight because overweight dogs seem more prone to developing lipomas.

No, you cannot contract a lipoma from your dog.