Hi All, as explained to me by two vets and substantiated by info found at Cushings sites on the web there is a distinct difference in how Cypro and Permax work. One treats the symptoms that develop as the extra hormones cause havoc in the system, the other (pergo) attempts to treat the release of the hormones themselves thereby reducing their damaging effect. Does this make sense? Has anyone else heard this? It is for this reason that I chose Permax to use. I would rather stop the hormones before they get into the system. Also the price is fairly close these days. And the problems with pergo were back in the days when much much higher doses were given. I queried my vet on this too and we have discussed the possible side-effects. What it boils down to in my case is that the side-effects are after long term use and we may not even have the time to see them develop. Not a happy thought but a realistic one. In the meantime I am happy with the dose of .25 mg daily. About $40 US a month. (Good news- we were driving an hour away to a WalMart for the script and have talked a local lab into cutting us a deal at the same price since it is a long term prescription!!!) Looking forward to more of this discussion. We learn by sharing. Chris in California