The answer as always is: "It depends."
Good bone or the right (preferable) type of antler doesn't require stabilization typically, because they're the premium, low pith varieties. Ideally, Sambar if we're talking about stag. Many other types of horns and antlers don't require stabilization either, and in many cases, they don't stabilize worth a damn anyway.
Now, if you're trying to use some random antlers from white tails, etc, then they're usually not that suitable for knife handles, although in limited cases, there are small sections that are, especially if it's very old big examples, however, knowing what to select, and how to process it, is something you develop over years of use, with all the requisite successes and failures, and not likely to be viable for a novice. Best bet is to buy some from a reputable vendor, although sambar is getting hard and harder to find, and is difficult to select via the internet, this is another cultivated skill, and highly personal, the stag I'd select based on how I like to work it, have it look when finished, in conjunction with the type of knives I make, and the processes and tools I utilize, may not be the same as would be best for another maker.
Sambar is the king of stag, but old european red deer were used quite often a century or two ago, back when the deer were much bigger, due to less encroachment of society. Some of the more finely, but heavily textured examples used on some of the old golden age knives were this type of stag and not sambar.