Guinea Fowl Lost All Mobility in Feet

These pictures are not for the weak stomach. I'm just looking for answers as to what happened to my guinea hen so I can prevent it from happening to my others and my chickens.

A few weeks ago this particular guinea had incredibly swollen ankles and was having a very hard time getting around. We seperated it and thoroughly inspected it but could not figure out what was causing it. I searched and searched threads but found nothing except bumble foot which I knew it was not. It started to to better so we just presumed it was on the road up.

This week it took a turn for the worse. It could not hold on to anything to land anymore and couldn't stand. The chickens and other guineas took advantage of it and ripped a big hole in its back. We sprayed him with blue cote but ultimately made the decision that his quality of life was gone.

When we put him down today we decided to perform a necropsy after to determine what had happened. My fiance cut open his foot and cut open the swollen ankle to see if there was pus or something else. Nothing came out of the swollen part besides the normal flesh and blood. However, when we cut open the foot above the toe it looked like it was rotting inside. His toes had no movement left in them. I guess I'm just trying to figure out what caused the below picture.

It looks as if his feet may have frozen. When this happens the bird walks around in a very 'stilted' fashion and eventually the feet or toes dry up and fall off. Euthanizing him was probably the kind thing to do given the degree of the damage. Birds can get around fine after losing a toe or two, but his entire foot was 'dead'.