Deborah, unfortunately frogs will do what frogs want to do and land themselves in a whole bunch of trouble.
There is not very much you can do about, unless you install a new pond with greater depth.

I used to keep four 100 gallon preformed ponds, that I had linked together, open all winter, with a small water pump running 24/7.
Keep a watchful eye on it though, just a change in wind strength or direction and it could freeze up very quickly.
If you could put a tarp or boards over it, that will help keep the cold winds off the water surface.
"Horton"

1. Are you sure the frogs are "dead"? The one the dog got is pretty olbvious. Frogs however, hibernate underwater all winter. So as long as your pond doesn't freeze solid, the frogs should be ok.

Just because they are in the bottom of the pond doesn't mean you need to take them out. And if you do, you will kill them. Just leave them be. They absorb O2 through their skin during the winter.

Just keep a small vent hole in the top of the pond.

I live in IL. I leave my bio filter, and pump run all winter. I add bacteria to the water in the spring to help jump start the bio process.

Horton, the tip on using boards...that's a great idea. Since the pond is directly in front of our front porch & door my husband is not keen on a tarp but boards will be much less obtrusive. I appreciate your trying to "lighten" my guilt load on the frogs...thanks.

groundbeef1, the two remaining frogs still swim around. The dead one was very obviously "dead". I've got a barley straw ball that floats so that should keep the ice from completely freezing over. Someone wrote that they put tennis balls in their pond for the same reason...I'm thinking of adding some to mine. I really liked the idea of swimming pool noodles but my pond is too small.

Hey there, Deborah. I still have no ice on my pond and it is two weeks since you posted last. Your weather leads ours so maybe your water has frozen since then. I thought I would add a comment or two. The Barley straw ball is not going to do anything to keep the ice open. It will just freeze in place. The tennis balls might work but I always found them on the bottom after they broke open and sank at the first hard freeze that lasted long enough to close the ice. They hold up just fine when you are hitting them around in hot weather but cold makes them brittle. You need something that can be compressed like an inflatable pillow tethered to the bottom so it stays in place. Ping pong balls work if you don't mind the dents that appear. You need to confine them to a small space so there is not a lot of water between them.If the ice gets thicker than the diameter of the ping pong ball the hole will close up anyway. I tried to keep a pond the same size as yours open all winter with a heater and wound up with a heavy frost layer on everything around the pond. It looked like the worlds heaviest fog. I wound up removing the fish on Christmas day. What a mess. I kept the fish in the garage in the winter after that until I could dig a bigger pond a couple of years later. Horton's wood cover sounds like it could be a lot safer than a plastic sheet. The potential problem I see would be if the wind could lift it up. A cement block would solve that problem.
There have been a number of threads on keeping the frogs alive during the winter. Lots of failures too. I haven't tried because frogs don't manage to get to my pond. However, after reading many threads on the subject I think I can suggest a solution to the problem in the future. By the way, this is not my solution, it is suggested by someone else who has a web site elsewhere. I just can't remember where it is. An area close to the pond should have a hole dug 12 to 18 inches deep that is backfilled with loose compost or chopped dried leaves or even sand. The frogs will go to the bottom of this backfill and hibernate until spring. Material such as quilt batting can strangle or suffocate the froggie as it shifts around. Otherwise, if you have a properly maintained garden area, the frog will be just as happy there since it would be easy to dig itself in. Freezing does not harm a frog. They produce their own anti-freeze. They are killed by dehydration. I once found the dissicated remains of three frogs who made the mistake of using a bag of lime in which to hibernate. I have also found a seemingly dead frog in the bottom of a ball of soil in a flower pot that broke. I left the ball of dirt in the sun frog side down and as it thawed the frog thawed too. It found a new spot to dig in since the soil scattered. In a deeper pond they would be safe in a bucket or pot of sand or clay such as you would use for a water lily. Sandy

I'm in IL. My 3 leopard frogs have settled down for a long winters nite in my pond. Nestled under my secondary pump,and the pea gravel I have at the bottom. They seem rather peaceful, and should emerge come spring. I have an aquarium bubbler working, as well as the pumps.

Hello again,
our efforts to keep the pond from freezing over seem to be working. A big THANKS to all of you for your expert advice.

It has been REALLY cold here...when we left for the weekend on Friday it was 12 degrees! I checked the pond today... a ring of ice has formed along the furthest outside edge but the center is still wide open. We are thinking that the ripples from the pump/filter and possibly the "heat" that the motor produces are keeping it open??? Either way we're happy to report all is well for now :-)
Sandy ~ next year I will try your compost hole idea.

Hey, Deborah. My pond is close to freezing over now. Temps have been 28oF or thereabouts but it is supposed to warm up to 36 today. The waterfall is almost frozen closed. I am amazed yours is still going. Are you using a submerged thermometer?
A friend says frogs and toads and salamanders go to the middle of her composted leaf piles every winter and they are raised. She keeps a tarp on top to keep the leaves from blowing away. Sandy

Hey Sandy,
I don't have a thermometer in the pond...do I need one?
My fish are very fortunate, so far the pond hasn't frozen over. Last month we had single digit temps for over a week and record snowfall too...all along there's been an opening the size of a basketball directly above the pump.
We had a warm up and a bad rain/wind storm over Christmas. Quite a few leaves blew into the pond...I wasn't here to clear them out and some settled to the bottom while others froze into the surface ice. Do I try to clean them out or (as my husband advises) leave well enough alone?
The sun is finaly shining today and almost half of the ice has melted.