Concerned About "Runt" Duckling Poop

[Taebaebae2014]

A few weeks ago, something got to my 4 ducks. Three are missing & I found one on the side of my house with no head. I was devastated.
A couple weeks ago, I got 5 new babies. A cayuga, a mallard, a pekin, a welsh harlequin & a khaki campbell. We all know ducks grow very rapidly. However, my khaki hasn't grown at all! He runs around with the others, eats, drinks, everything! I thought maybe he could just be a runt. But over the last couple of days, I've noticed he has foamy, white, watery poop. Almost seems like nothing comes out but some foamy white stringy bubbles honestly. Is there something wrong with him? He doesn't seem sick but I put electrolytes & probiotics in the water just in case. I have attached a picture of the size difference for reference.
Side note: I refer to all my babies except Harley as males until I know otherwise. My harlequin is a female.

 

[casportpony]

Welcome to BYC!

But over the last couple of days, I've noticed he has foamy, white, watery poop. Almost seems like nothing comes out but some foamy white stringy bubbles honestly. Is there something wrong with him? H

That is not normal. Do you have a food scale that you can weigh it on?

 

[Taebaebae2014]

I have a little mini scale somewhere. Not sure if I can use that if I can find it?
Which part wasn't normal? The size, the poop or both?

 

[casportpony]

I have a little mini scale somewhere. Not sure if I can use that if I can find it?
Which part wasn't normal? The size, the poop or both?

Both. It should be growing and it should be producing real poop. Can you post a picture of it's poop?

 

[Taebaebae2014]

I don't currently have a picture. I can try to get one though. I clean out their tote every morning & every evening. As of 3 days ago, they are mostly in the backyard while I'm home, fully supervised. Here's a picture I just took of the size difference. The others always seem to be protecting the khaki or something.

 

[casportpony]

Can you get some close up pictures of it's eyes?

 

[Taebaebae2014]

I haven't noticed any runny eyes or nostril leakage.

 

[Taebaebae2014]

I just took a picture of his rear but I'm not sure if I should post or not? This is my first thread so I'm not sure how much is appropriate. It looks much different than the others.

 

[casportpony]

I just took a picture of his rear but I'm not sure if I should post or not? This is my first thread so I'm not sure how much is appropriate. It looks much different than the others.

Go ahead and post it.

 

[Taebaebae2014]

Looks unclean or unhealthy to me. It attempted to poop as I picked it up. All the other ducks look clean down there.