Hi Jabo808, Glad to have you here.
You'll find a lot of resources on this site. Check out the Pocket PC forum topic for a lot of info on Pocket PCs. Most of this will also apply to smartphones. Of course, if it's a PalmOS Treo, try the Palm forum.
You should find things like links to freeware sites and other informational sites on the web that are relevant. Some examples you might check out also are:
http://smartphonethoughts.com/
www.brighthand.com
http://www.pdabuyersguide.com/
Some places to search for commercial software are:
www.pocketgear.com
www.handango.com
You might also try (again assuming you have a PocketPC device), searching in Google or your favorite search engine for something along the lines of
("Pocket PC" OR PDA) veterinarian
to see what you can find. You may have best luck finding specialized software at veterinarian sites.
Good luck, and I bet once you get used to it you'll never want to be without it!