I'm not sure what's wrong with one of my ducks

[Ahmad_Ali]

So, I've noticed that one of my ducks has started to show odd behavior for eg its now slower and less energetic than it used to be, whenever the other ducks used to run he used to be the fastest one and now he lags behind l, also he runs with his head hunched in towards its body, while previously it used to run with his neck straight and outward. He's eating fine and does run when the other ducks run. Also there is a chance that he could be fat. I've attached a photo, his neck is hunched towards its body rather than he used to have. I would appreciate any guidance. I really love him so I don't want anything to happen to him. If he's sick its better if I could catch and deal with it early on.
And apologies if this is the wrong category to post this, I'm kinda new

 

[Cassandra Lana]

How much does he weigh and also feel the bone right in front of his legs. It should pretty prominent but not jutting out, with some substance on both sides.

also is that a anacona?

 

[Ahmad_Ali]

How much does he weigh and also feel the bone right in front of his legs. It should pretty prominent but not jutting out, with some substance on both sides.

also is that a anacona

How much does he weigh and also feel the bone right in front of his legs. It should pretty prominent but not jutting out, with some substance on both sides.

also is that a anacona?

Yes it does look like an anacona, I had 4 ducklings and I've raised them, I don't know much about ducks so I don't really know what breed all of them are but I've looked at some pictures of anacona ducks and he does look similar

I haven't weighted him yet, I'll do it as soon as I can. Also its been too hot here 43°C and they are usually in the sun is it possible that could be the culprit, since it is eating food and everything pretty much normal, the poop is normal too.

 

[Cassandra Lana]

I think your duck is a anacona without cheek spots. You can just pick him up and get a feel for his weight, compare him to another duck his size (exuse to snuggle!) My anaconas don’t run with their head out unless they are playing so that could be part of it too

 

[Ahmad_Ali]

I think your duck is a anacona without cheek spots. You can just pick him up and get a feel for his weight, compare him to another duck his size (exuse to snuggle!) My anaconas don’t run with their head out unless they are playing so that could be part of it too

Thank You for the advice I'll check up on him and I'm really relieved. I've also started some vitamins and fruits that I'll be adding to their diet occasionally