If a fish has swallowed the hook too far to be removed without killing the fish, can the fish still eat with the hook lodged in its throat? How about a treble hook? What's the proper thing to do?

The first thing is if it is keeper, chuck it in the cooler but if not and the hook cannot be easily retrieved the best way is to leave a length of line. A common misconception is to cut the line short, but cutting the line short interferes with feeding. A longer line allows food to pass by and be swallowed.

Another common misconception is that hooks will "rust out". Doesn't happen. Hooks are either "shed" or encapsulated.
Here is a short study to prove that point.

http://www.fish.state.pa.us/images/pages/qa/fishing/catch_rel.htm

You will find plenty of opinion to the contrary but scientific studies agree, that hooks generally do not rust out, not even in salt water.

Here is a video on how to remove a nearly swallowed hook through the gill.
http://www.youtube.com/watch?v=3RGTL9RBG2s

This will work with some fish.

One way to reduce fatalities is to fish with circle hooks. Circle hooks will usually hook in the corner of the mouth, and the percentage of hookups is about the same as with other types of hooks. Here is study that shows why that is true.

http://www.dnr.sc.gov/marine/mrri/insh_fish/reddrum/gonefishin.html

Sometimes a fish is hooked in the heart (right between lower portion of the gills) or in the gill. The chances of survival or negligible in this case. And if fish is hooked really deep the hook will often penetrate a vital organ.
http://www.iowas.co.uk/fish%20anatomy.html

Sad but if it is game fish and not a keeper it is not worth trying to keep it. There are plenty of critters out there to take care of it for you.

+1

Big fan of circle hooks here. Last weekend had a buddie that was deep hooking small crappie (they were biting really soft). Got him a circle hook and he didn't have that problem anymore.

good question/thread

i think id keep it, if it measures or maybe find someone to give it to. In fresh water, I have cut the line & thrown that fish on ice so they don't bleed out inside my cooler. If im keeping it anyway & the bass are boiling, ill reach for the pliers & jerk it out in a hurry then, throw it on the deck to bleed out. when it stops bleed ill throw it in the cooler. different if you have no cooler to keep it i suppose.

My brother can almost always get the hook out without tearing them up. His fingers are long and skinny & he has the patience taking his time to save as many as possible.

I know salt anglers cut the line & let em loose all the time.
Some say it rust out in days while other say not. I think the bigger the fish & smaller the hook the more chance they will be ok. Don't know for sure & am curious to hear what other say...

Great advice so far.

I can't really think of anything to add to the thread other than touching upon prevention. As far as largemouth bass fishing is concerned, a swallowed hook is the result of poor skill and technique.

Other than largemouth, I can't really speak from a highly experienced standpoint. However, I am fairly certain that most "swallowed hook situations" could have been avoided with better technique.

Learn how to properly read a strike. Not only will you avoid gut-hooked fish, but you will catch more fish. Most people would be completely shocked if they knew how many fish they miss in a typical outing (because they weren't watching their line and reading the strike).

I have caught LMB that once landed, have found "other's" hooks still in their throat. On some occasions, I have been able to safely remove both hooks, and other times, just removed my hook and looked like I would do more damage than good trying to remove the "old" hook.

I have had this happen several times as well. The fish almost always seemed to be in good health, so I can only conclude that they still eat and go about their business in a fairly regular fashion.

In largemouth fishing, it seems that gut-hooking becomes most problematic when using Texas-Rigs or weightless worm presentations. This is due to the slack line.

I use Texas-Rigs and weightless worms almost exclusively. Here are a few things that seem to help me:

1. When I use soft plastics, I utilize a rod/reel that were designed specifically for worm fishing.

2. I put a great deal of emphasis on the visual aspects of reading a strike. I use either yellow or orange braided line with a fluoro leader, which helps me to visually see the smallest line movements.

3. If I see any line movement at all, I reel up and set the hook. You want to wait for a second or two, but if you give them too much time, they will swallow the hook. It often looks like a very small "twitch" or a "twitch twitch."

You can go by feel alone, but you will miss more fish and experience quite a bit more gut-hooked fish.

I carry a water proof laser orthoscope in my tackle box and remove all hooks that I find in the fish I catch without even removing the fish from their underwater enviorment. I am a serious catch and release lunatic fisherman.

A large circle hook is a real ticket to avoid a swallowed hook, except they get heavy....

I wish I could find a large circle in a very light guage.

Right now I grind my own hooks down* and its worth the effort as I like the results.

If any one can recommend a light and large cicle please do.

* I just lay em flat on a power disk grinder and thin them substancially.

They dont really make circle hooks for soft plastic presentations and worm fishing for LMB though so circle hooks arent for everyone! However I agree they paying attention to what you are doing and recognizing strikes is a big help. But even in doing that I have had some bass just annihilate my lure and swallow it still.

I dont put circle hooks on any of my bass lures. I have to disagree about me poor angler if a fish swallows my wacky rig. You can take a pair of hemos or long pair of needle nose pliers and go through the gil plate and first gill to access the hook. Roll the hook over the same direction it went in and it will come right out. Just be careful with the fish if your practicing catch and release.

The act of fishing in inherently dangerous.... to the fish.

As they say, beauty is in the eye of the beholder. Every angler's skill evaluation is a personal thing.

For me personally, I cannot except gut-hooked fish. I know, for a fact, that I can avoid the situation by being a more acute angler. When I deep hook a fish, I feel sloppy. Feeling sloppy grinds away at my confidence, which in turn makes things even worse.

Now, it happens from time to time. It isn't a totally avoidable thing, but trust me, you can almost entirely rid yourself of this problem by upping your soft plastic game.

Again, to each his own. A lot of guys keep their catches, so this completely changes the equation for them. For me, I set out a few years ago to perfect the Texas-Rig and Weightless Worm technique. I still have a lot to learn, but after a bunch of hard work and research, I have really started to master the concept.

And yes, I realize that I am an annoying perfectionist.

Wow. You do know fishing is supposed to be fun right?

I'm working on that too.