I ran into a couple of raiders that had dogs with armor which I thought was cool! Of I thought if I equipped it into Dogmeats inventory it would equip him with it, apparently I was wrong! Any suggestions? Can Dogmeat even where a dog collar?

The same armor those dogs have equipped can be used by young meat...err...dog meatz.

just test out items by giving them to him and they can be used by hitting the button if it allows.

...but bandanas, goggles, and the light-heavy variants cant be used and the muzzles/collars.

Need to hit the triangle if your on playstation but the button to equip should be there if the item is usable.

Yes he can wear armour just like all other companions and settlers but simply adding it to their inventory isn't enough; You need to highlight the item in their inventory and click the equip button, you'll see it at the bottom of the screen.

Dogmeat can wear all armor items that other guard dogs wear. When he was my companion, I had him sporting a spike muzzle, chain collar and armor that I looted off a raider guard dog.

Note however that dog armor is purely cosmetic. It does not have any armor value. Or more precisely, it have ZERO armor value.

Furthermore, it cannot be modified nor improved at a workbench.

LOL, I had a feeling there was a solid reason I was avoiding it. Cosplaying dog companion, damn Bethesda, that's twisted.

He can also wear the welding goggles and a bandanna. It is hilarious.

Newer understood how wearing welding goggles can make you "perceive" better. That thing makes you almost blind.

They prevent the rads from causing cataracts

Works for Riddike...