i must be hard on mine, I very rarely lose - Molly is the hardest, she is the most skittish out of hte two, and most of the things I have to do to her are done on teh windowsill as that is her bolthole!! No one else would attempt it with her, they would think the growling meant a nasty cat that would attack, but she is all noise.
Stronghold is a prescription only item, you would be able to get it online, but would have to get a prescription from the vets first.