Lipomas

Lipomas are fatty tumors surrounded by a fibrous capsule that isolates the contents from the other surrounding body fat.  They are soft, rounded and smooth with a fat-like consistency.  They commonly occur in the subcutaneous tissues of the ventral thorax and abdomen of middle aged and overweight dogs.  They are not painful but can grow to be quite large and cause irritation.

Lipomas are the most common lump that veterinarians see, and it is estimated that 30% of the tumors found are in the skin of dogs and cats.

The nature of the fatty lumps is not known until cells from the lump are removed via a small needle and then examined under a microscope.  Questionable cells may be sent to a veterinary pathologist to obtain a definite diagnosis.

Cancers are malignant growths that occur when cell dividing “brake” mechanisms go awry.  The causes of these malfunctions could be inherited or acquired’ some breeds seem to be more susceptible to particular types of inherited cancer.  Acquired cancers can arise when the cell mechanisms are interrupted by a virus, irradiation (skin cancer for pale skinned dogs) or by toxic chemicals (mainly from chemicals in the environment).

The best option is to have each lump tested and/or removed, especially if they are growing at a fast rate.

Other types of lumps and bumps:

1.   Sebaceous Cysts:  Sebaceous cysts are small superficial bumps that are actually plugged oil glands in the skin.  They can be composed of dead cells, sweat or clear fluid that often ruptures on their own.  They can be removed or can be watched for any signs of changed.  Once gone, they may never return again; or they could become chronically irritated and need to be removed.  Certain breeds such as Cocker Spaniels are more prone to these types of cysts.  These sebaceous glands in the skin do occasionally develop into tumors called sebaceous adenomas.

2.   Non Cancerous lumps:  Cysts, infected hair follicles, warts and blood blisters (hematomas) can also cause discomfort for a dog.  These non-cancerous lumps fortunately have less of a health impact than cancerous growths.

3.   Cancerous lumps:  These types of growths can be one of two types, but occasionally share the characteristics of both.      

a.   Malignant:  these lumps tend to spread rapidly and can metastasize to other areas of the body

b.  Benign:  these growths tend to stay in the place of origin and do not tend to metastasize however they can grow to huge proportions

Treatment:

Surgery:  The main way to eliminate a dangerous lump is to remove it surgically

Chemotherapy:  Highly toxic chemicals are used against the rapidly dividing cells.  Used in combination with surgery, the vet can gain the upper hand in achieving a cure for a cancerous lump.  Chemotherapy may also be used after a mass has been removed

Radiation:  This is used for tumors that have not spread to other areas in the body, and provides a potential solution for some localized tumors.  Beams of photons, electrons or gamma rays are focused on the tumor.  When these waves hit the nucleus of the cell it alters it thus destroying the ability of the cell to divide and grow.  By slowing the growth rate, and hopefully killing the cell, the tumor should shrink over time.  Radiation affects both normal and cancer cells, but the treatment is designed to minimize the effect on the normal tissue.  Radiation can be used in combination with surgery and/or chemotherapy to control or destroy a tumor.

Cancer begins without symptoms.  There is no sudden onset fever, vomiting or diarrhea to let the owner know that there could be something wrong.  Owners need to be vigilant, especially with middle age, older dogs and dogs that are overweight.  Annual checkups with thorough hands on exam are essential, but owners must check for new lumps and bumps.