Liz Buchanan BVSc MRCVS
Hello - and as they say, location is everything. I'm not sure of the size or age of the loveable beastie this sits on, so scale is quite important, too. From this angle, this could simply be a nipple, but if it is then you will be able to tell - simply look for the row of nipples and compare. Other possibilities are cysts, cancers (benign or sinister), enlarged follicles, inflammatory reactions, fly bites ... a huge array of things. It would be good for your vet to see it in context and either to put your mind at rest or carry out tests if appropriate. If you type 'lump' into the search-bar of the blog, a few of us have written helpful essays on the subject. We'd love to hear how you get on.