Yes - My kitty Daisy had a lump too - but don't panic yet! If Luna just recently had some injections, she might be having a small reaction to the medicine. This could go away by itself!

But, since you are going to the vet, you should discuss the issue of having future injections done in the legs rather than by the shoulder blades. I don't mean to sound upsetting, but the reason for injecting into the legs is that if Vaccine Induce Sarcoma does form, it is possible to remove a limb and stop the problem. However, if the lump is in the shoulders, it may not be operable.

My Daisy (age 6) had a lump on her shoulders starting in March one year, but it was not associated with recent injections. The lump got bigger ... and in November I had to help her to the Rainbow Bridge. There were a couple of treatments possible - but the chances of long term help were very small. I chose not to have the surgery.

I'm hoping for a good report for dear Luna - don't dwell on the bad possibilities - it won't help (take it from an expert!)