I want to investigate more about this muscle/skin thing.Yes the drug is the GS441524. We were told subcutaneous and not to put it into the muscle. We were also given a chart as to where to give the injections, which is in the front shoulder area, to the side and not over the spine. Did your cat have wet or dry FIP?
We weren't given any chart, and because he was a feral cat and very handy, the best we (the lady at the shelter) could do, was to give the shot in the cat's left hind leg.
He had a wet FIP.
I wouldn't like to dash your hopes, but my cat didn't make it.
He finished his treatment mid July, he died a month later... His name was Matisse