Looking at CO's website, I see that "OnePass members can earn one (1) OnePass mile for every dollar spent (including tax, fuel and security surcharges) when transporting a pet using Continental's acclaimed PetSafe service" which is different from "miles for every mile the pets fly on cargo", so the number of miles you're looking at may be a lot smaller.

http://www.continental.com/web/en-US...s/default.aspx

Also, I imagine these would only be RDMs, and would not help with Elite status.