[Farming101]

Hi,
First time on this hope I can make sense of my issue.
I have last years ewe lamb who has gone off her feet, she also is a little runny (poo). She has had heptavac and wormer (I have also done a worm count).
She has also had magnesium 3 times now. She is eating and drinking. Doesn’t look upset.
Another lamb had this and responded a lot quicker than this one.
It only seems to be the lambs who have had this issue.
Can anyone give me a clue what this is.
I have ordered a vitamin drench, if people can not help me on here I will be taking her to the vet.