My heart goes out to you about Jack. 5 years ago I lost a big love in my life, Attila. We went to have him vaccinated for an Interstate flight but unfortunately he didn't leave Victoria. The vet had felt lumps and took a biopsy. Attila had cancer, and we made the hard decision to have him put to sleep. I cried for weeks, and couldn't even look at his collar with out balling my eyes out. He was a beautiful dog. I really hope Jack pulls through for you all, and you avoid the heart ache. Attila was just short of turning 6.