Runner drake just died

[forestcrump84]

A sad story a week ago my five ducks all one year old came back from there ponds ,but my drake wasn't with them , I searched for an hour around the land and couldn't find him as I was giving up to the I saw him sat in a ditch in the middle of the wetland area I picked him up and took him back to the home ,he had gone off his feet he could not stand but for a few seconds,i read the forums here and elsewhere and it sounded like rickets so I gave him the rickets diet everyday since,4 days ago I went to get some duck feed pellets for them all as they had been eating the chickens grains since they came here 2 months ago and free ranging 8 until 3 everyday ,I keep there water bowls well cleaned every day maybe twice fresh water and muck out every 3 days all bedding ,Today I went in and picked up the drake and took him into pasture to just be around me when I was out working he didn't seem as lively as yesterday he just sat with his head tucked in and didn't seem to even eat grass or nibble around ,after an hour I picked him up and carried him in his stable with the others and fed them all there pellet feed and fresh water he started nibbling while still sat like he has the last week with his rickets feed and this new one the last 3 days but he seemed too be struggling to swallow it but then he drank a little and took more feed then he just died ,I just don't know what to do I have taken him and buried him but im at a loss too what happened to my boy and know im worried ive let him down
thankyou
he was 1 year old -I was told
he free ranged in wet land areas
he ate a mixed feed barley-oats-grain
he did have discharge from his eyes clear watery since he went off legs
he didn't stop eating or drinking
he was bathed once a day in a bath warm water and dried off afterwards

 

[Amiga]

He could have eaten something toxic, he could have picked up a parasite, fungal or bacterial infection. He could have been bitten by something and had internal injuries or hidden infection from that. Sometimes ducks have strokes or heart attacks.

I understand the feeling of letting them down. It is so difficult to lose a duck.