i know im a bad owner i lost my dog... i made him wait some where and cant remember where so is there anyway to find companions you "lost"? i heard the patch thats coming will mark your companions on the map but that could be a few weeks
and 2nd when i walked out of a casino it must have gave me cass's weapon which i must have sold because now shes only using her fists and doesnt use any weapon i give her. is that just a bug or do i need to find her weapon again?

Well if you "sold" it, then there's a good chance it's gone. And if you've lost Rex, either backtrack or just load up a save from before you lost him.

For Cass, if you also give her ammo for any weapon that you give her she should then start using it.

With regards to Rex, if you're really lucky you might move somewhere the game decides is out of range and automatically send him back to the King or the L38 but the 'out of range' doesn't happen all too often (it took a while to kick in when I'd lost Veronica), other than that there's waiting impatiently/patiently for the patch to appear.

Companions losing their default weapons or having them show up in your inventory upon leaving a Casino is bug. I haven't run into it myself personally, but even if you hadn't sold it, from what I understand you wouldn't have been able to give it back to her anyway, since it's a 'magical' special weapon that shouldn't be viewable in inventory at all. So basically, if she won't even use a weapon you give her, I'm pretty sure you're borked and have to reload. (edit...good point about the ammo. They need it in order to use a weapon you give them. Maybe she'll at least use something then so you don't have to reload. )

Always hard save before exiting a casino....or if you're just going to gamble/don't need their help inside, leave them waiting outside.

When i entered the strip from freeside.. Gannon just sort of.. poofed.
I walk around everywhere and can't find him, and he has my favorite armor at the time which is the Vault 34 security armor. I've tried everything to get him to reappear and my last save is too far back..
I'm debating making a new character but i still want to see the ending from the NCR side of everything.

thanks for the help guys ill try giving cass ammo tonight and im sure ill find my dog