Will Falconer, DVM Moderator
Wow, Cheri, just that one shot and a life of suffering. Truly a sad story. If you haven't already, you'll want to get on balanced raw food (and watch for my Vital Animal Podcast interview with Thomas Sandberg, animal naturopath, who's seen raw food cure about 85% of the allergic dogs in his vast experience with thousands of dogs). You will also hear on that episode how longevity increases substantially, making 12 years look like barely middle age.
The other is to hire a dedicated homeopathic vet, as this is chronic disease, and trying "homeopathics" is decidedly different than hiring a professional trained to cure the chronic cases like Murphy's. I walk you through how to choose wisely among my colleagues on this page.
All the best. I think there's definitely hope for Murphy.