Hello, sorry to hear about Chiquitin. It looks like a small benign cyst, however, the only way to know is to remove it and submit it for biopsy. The biopsy will tell if this is an aggressive lesion or benign. It does not look like something that could be contagious.
I would recommend scheduling and appointment with your veterinarian to have this evaluated and removed. In the interim, you should monitor the lump for changes in size and form and relate any changes to your veterinarian.