6. Lumps on the skin
Lumps are quite common in dogs, and although most of them are likely to be benign, there may be a tumor growing on the dog. Some other possibilities could have very serious causes such as insects burrowing into the dogs skin and laying eggs, or the beginning of a deep infection, or it could be something like scrapes or shallow wounds from rocks or wood. The possibility of cancer from one of these lumps is quite small, but each lump should be taken a look at to assess how they got there, and how to treat them.