Why is frogs dying in my pond?? Pic

[small fish]

In less than 2 weeks I have found 2 frogs in the pond dead.  The first one I saw laying on the bottom of the pond on his back dead.  I scooped him up with a net.  He had a small hole in his side with goop squeezed out of it.  I thought it very strange as it is the first frog I have had come up dead in the pond.  Thought maybe some thing bit him.  Today I found another frog dead in the pond. He was floating under a lily pad, but I could see his back legs sticking out from under the pad.  Netted him out but there does not seemed to be any thing wrong with him. No hole. He does appear a little fat but that is the way I like my frogs to be.  Check out the pic and tell me what you think.  I have a number of different kinds of frogs in my pond in the past 3 years but I have never had one die in the pond like this.

Myra

[perplexed ponder]

Myra,
I'm sorry about your frogs. It's so upsetting when I lose one, and I too lose them. I am not an expert on frogs, but i would gamble that the first one was attacked by a heron/egret or similar bird. Possibly the second was struck, but not pierced? Could have hidden somewhere like a skimmer until it tired out and could not fight the current in there anymore. I have had that happen. Is the one in the photo missing an eye? maybe he got pecked there?

[Rick]

Possibly the cold?

[small fish]

perplexed, I did think when I first looked him over that one of his eyes did not look right but later thought it did not look that much different than the other one.... but maybe you are right....

Rick.. I don't really think it would be the cold.  I am in Louisiana.  We have had one real cold spell where it was down to 29 degrees.  These frogs have been in this pond for 3 years and seemed to weather the winters in the past ok. 

Myra

[perplexed ponder]

I don't think it's the cold. We are in Michigan and have lost many frogs over the years do to freese/thaw cycles. Last year pond totally froze over, many inches thick. The frogs died. I think we had one survive. They didn't look like your frogs at all.

I read a very technical article last year on the frogs system of producing glucose in winter. Simply put, It kind of acts like an antifreeze. If they freeze/thaw and can't produce this glucose fast enough for another freeze cycle, they get ice crystals forming in thier bodily fluids which kills them.
I'm pretty sure your frogs would not have gone through this type of thing in LA.