How do you know they have worms??

I give my chickens Verm-X once a month as a preventative for worms.
I am now wondering if this is enough? I have 3 hens at the minute who should be laying (all the rest are too young yet). One is laying normally, one is laying a white egg (when it has been brown for the last year!) and one seems to have a soft shell, as underneath the roost for the last few mornings there has been an egg on the ground, which looks like it has just 'fallen out'!!
They all get Layers pellets in the morning first thing, they have mixed corn in the afternoon and have an oyster mix grit ad lib when they want it.
Only one had a slightly pasty bum tonight when i checked them, like two feathers stuck together. They are all starting to moult too.
They aren't fat chickens and you can feel their breast bone, (except jimBob the roo), they don't always finish their food so its not like they are hungry.
The other thing i noticed tonight when i checked was that Jimbob had nothing in his crop, the girls did they were nice and full but nothing in his, is this normal, has he digested it quicker?? He was certainly eating his corn at 4pm this afternoon.
Does it sound like they have worms??

 

Quote:None of those symptoms sound related to worms to me.

The light colored egg is probably coming from a hen who is getting ready to moult. I have just recently learned that the color of the egg will often lighten toward the end of the laying cycle. I've been getting some nearly white eggs from some of my brown egg layers too.

If i were you, i would cut out the mixed corn afternoon snack at least until their moult is over. They're using up a lot of extra nutrients right now, and the corn doesn't provide much of what they need.

Your rooster is likely just eating more sporadically throughout the day. Either way, if he's eating, and he's healthy and active, i wouldn't over-analyze the size of his crop.

Being able to feel their breast bone is not a sign that they are skinny. Now, if you can pinch their breast bones and not pinch meat (with whole fingers), then you have a chicken who is starving.

Thank you for your reply, its very interesting, what would you suggest I fed instead of the mixed corn then to help them through their moult??
I had wondered of the change of egg colour was to do with the moult!

 

I didn't think you would have verm-x over the pond but def not a wormer. Was trying to keep my hens as natural as poss, I don't like giving wormers and things unless I have too.
Do you all give them wormers that go in their food or liquid that goes down their throat??