Many dogs develop lumps on the skin during their lifetime, and Boxers more so than other breeds. All lumps are not created equal. Some are infections surrounding a foreign body eg grass seed or thorn; some are cancers which can spread throughout the body, and some are cysts full of fluid. Dogs may have several lumps at the same time. What is best to do about these lumps? It is a good idea to go over your dog once a month or so, checking for any changes in shape. If a lump is found that is painful, the a bruise or infection is likely. A non painful lump is most often a cyst or growth (cancer). If a skin lump grows rapidly or bleeds on the surface, get your vet to look at it soon. A nodule which is smooth on the surface and grows slowly or stays the same size is less likely to be malignant, but there are no hard and fast rules.
When checking skin lumps, the usual test your vet will do is called a “fine needle aspirate” (FNA). This is a simple test able to be done without anaesthetic, but it has limitations. A needle is inserted into the lump and some cells sucked out and looked at under the microscope. If the lump is the same sort of cells throughout, then an accurate diagnosis can be made, but if the lump has pockets of fluid, blood or infection then results of FNA may not give a diagnosis. In this case a biopsy, or complete removal of the lump, usually requiring anaesthesia may be needed. A biopsy is a thin slice of lump, preserved in formalin, then carefully prepared in sections one cell thick for an expert pathologist to look at under the microscope. The cells present are identified, and an accurate diagnosis of the lump can be made.
This is important, especially if there is a chance that the lump could be malignant (spread throughout the body). If a malignant growth is detected at an early stage, the complete removal and cure may still be possible. Some lumps are benign (do not spread further) and especially in an elderly dog may be best left as they are. Anaesthesia and surgery may be more hazardous than the lump/s where the dog has other health problems eg heart disease.
The main thing with skin lumps is: know what you are dealing with. For this an accurate diagnosis from veterinary tests is essential.