Two guns.
Stainless Ruger .22 Government Target model with 8" bull barrel and target sights. Only ever used for teaching, plinking, rabbits, squirrels and the occasional upland bird (if I can sneak up on them close enough to have a chance at a decent shot). When carried (often not), carried open in a custom made leather flap holster. In snake country, loaded with snake shot (never had to shoot a snake yet though...in snake country I tend to stomp around and make a lot of noise to let 'em know I'm coming - and keep my eyes peeled). It was a gift and I love that little "game getter" gun.

Smith & Wesson Model 40 .38 Special. 5 round magazine, double action only, backstrap safety. I can put all 5 in the 10 ring at 15-20 feet, with either hand. If I've been practicing. That's point and shoot, the sights are crap and good luck with a 2" barrel anyway. In the outback, always carried, but never openly. If things look sketchy, I can pull it out and palm it and no one knows it's there. Done that a few times. If/when things calm down, I can slip it away and none the wiser. If carrying the .22, that's on the left, so the .38 is on the right. Theory is, while they see the flap holster still snapped down and closed, they won't be focused on what I've got palmed in the right hand. Eh...it's a theory anyway. Never been put to the test. If things look like going bad, can pop the first round into the dirt. The thing is so loud, and shoots such a frigging flame out the barrel, it's a bit like setting off a flash-bang. Especially at night. Real attention getter, and there are still 4 rounds left if the warning shot didn't work. Only time I've ever had to actually use it in the field, was once to scare off a small pack of dogs that had gone feral. The flash-bang effect did the trick. Been thinking about getting a newer one that is rated for +P ammo, but really, the .38 is a damned punchy little cartridge. Don't really need the +P.
Used to bring along a Mossberg 500 shotgun too, but never used it except for shooting clay pigeons, and a long gun is a pain in the butt if you aren't hunting, so I haven't brought it along for at least a decade.
Never really needed a self-defense gun in the field, but I consider them just another form of insurance. Better to have it and not need it, than to need it and not have it. The .22 is a great little game getter, but really it's mostly been used to teach kids and women how to shoot. It's great for that, because the sights actually work and it's heavy enough that it doesn't kick, and jerking the trigger doesn't have all that much effect. Perfect for teaching sight use and trigger control. (And basic handling safety.)
Over the years I've had a few dogs and took them with me. I love dogs and they are a lot of fun and a good alarm system. But I never felt they were any more a requirement than a gun. Nice to have, not really needed.