It's so funny. When someone says "lump" on back of neck or meaty part of the leg I always think injection site.
But, when I felt a lump on Catherine a few weeks ago, it never even entered my mind. I worried all night the night I felt it, waiting to call the vet the next morning. I got out her medical records (because I was freaking) and, yup, rabies shot 3 weeks prior and I had completely forgot!
LOL. Turns out it was nothing, just a white blood cell reaction to the Rabies shot.