Did it for years on coon dogs. It is effective at stopping theft. I made my own brands out of 3/8" thick copper sheet, you can also use brass or bronze. Copper is better but expensive. I cut out the letters on a bandsaw and attached them to all-thread rods. Not all letters work as good as we want them to, A's generally dont look right and B's usually look like a figure 8, hard to tell a g from a q, etc. Invest in an Oster electric shaver like the vets use, I have the one called the "Golden A-5." Its very important that you shave the spot to be branded down to bare skin or it wont work right on a dog. You cannot brand overtop of hair. I used dry ice and alcohol because it is cheaper and easier to get than liquid nitrogen. Nitrogen requires a special bottle called a "Dewar" to store it in, they dont carry those at Wal-mart!! Dry ice can be hard enough to get these days. You put the ice, alcohol and brands into a styrofoam cooler and when the "boiling" stops the brands are ready. You must have solid ice, alcohol and the brands together at the same time or the temperature wont be right. May take several people to hold the dog or sometimes they just lay there. Hold it on the dog for about 20 seconds{less time for nitrogen} and when the spot thaws out rub it down with a good layer of medicated vaseline. If you hold the brand too long no hair will grow back. Not long enough and the brand will be blotchy or incomplete.
We had a case here where the brand actually helped the dogs owner in court. The dog was a redbone that got stolen and but for the brand the judge said he wouldn't know one all red dog from another, or a black and tan for that matter. Walkers and blueticks can have one of a kind markings. Something about "possession being 9/10ths of the law.....Good luck. You can make alot of money freeze branding dogs at coonhunts, I probably branded 1500 dogs back in the 80's. Not sure what they charge these days. We tried tatto's and they hold up in court if it makes it that far. A good dog thief{no such thing} can remove a tatto and they really have no deterance value to keep the dog from getting picked up to start with like the visible brand that is very difficult to alter.