Chicken who has stopped laying

I would appreciate some advice concerning one of my chickens. She has never laid as well as the other hen, from the point of view of frequency, but also quality - the shell is always thinner. They have the same layers pellets, and grit is always available. A fortnight ago the chicken in question was laying fairly spasmodically - she laid eggs with soft shells on a couple of days, but normally in between. On Sunday she was very droopy in the morning - she spent a long time in the nesting box but didn't produce anything. She was quiet, her tail was down, and I could pick her up with no resistance so I knew something was wrong. I went to church and was going to see how she was later on. At lunchtime I was going to sit her on a hot water bottle in case she was egg bound, but she wasn't having any of it, and seemed a lot better. She gobbled some mashed potato (with some poultry spice in) and has been much perkier since, but hasn't laid at all. Out of the two of them she is lower down in the pecking order - I wonder if she is not getting enough to eat. The other hen is quite aggressive in wanting the best things - I have to shut the bossy one in the run so I can give the quiet one treats like the odd raspberry. I did find out on a random website that spinach and leaf beet can affect calcium absorbtion, and I had been giving them perpetual spinach to eat as the grass in getting a bit sparce. I've stopped this and swapped to cabbage. I 'm not too worried about the chicken as she seems so much better and perkier, but i wanted to know a) is there something else I could do and b) after there's been a problem how long does it generally take before they start laying again?
I worm them every month (Verm X) and haven't seen any evidence of worms.

Worms

Have you ever wormed them with anything other than Verm-x? as it isn't a worm killer, just a "make life uncomfortable for them" remedy.

I worm my lot twice a year with Flubenvet as well as using Verm -x every month.

Especially important if they are on the same ground for a long time, which can't be rested and rotated off chickens for at least a few months, to allow the worm burden to reduce by UV etc.

I would probably worm as a first resort, if this happened to my hens and then I would be looking for other alternatives.

Oh and if you see worms in their droppings they are pretty full of worms...so you probably wouldn't see them unless they were very badly wormy

Egg bound

If you do suspect she is egg bound a hot bath is much better than a HWB, and it allows you to add some Lavender EO to the water which will help relax smooth muscle even more than the hot water.

Weather

This very hot weather can put them off lay - one of my most reliable girls has gone a bit erratic in the last few weeks

Old Age

They are a couple of years old, now yes? so that will affect the shell quality, laying etc.

Lack of calcium

Do you give them cooked ground up egg shells ? as that can help with calcium absorbption as can cider vinegar in the water ( and with works!)

Thanks for all the suggestions! I did give them Flubenvet last year (and meant to repeat in the Spring but forgot) so I will try that. Do worms affect the quality of the shell?
They do have ground up eggshells in with the grit, and apple cider vinegar. They are about two years old, so age is a possibility as well as the weather. I will just have to be patient!!

Sorry, didn't mean to inundate you!

Yes, worms can make them generally "off colour" and yes that includes soft shelled eggs, not laying, runny poo, pale combs, being grumpy, mucky bums etc ....

I would worm them with Flubenvet if I were you...do you have some?

Think of it like " feeling lousy" if one had lice...same sort of low grade debilitation...until the burden gets high when it can become life threatening so not to be taken lightly.

Not suggesting for one moment that your chicken is like this and I only recount this tale as an illustration

but I once PM'ed a friend's chicken which died for " no reason" and the intestine were FULL of worms...and I mean FULL - - as in packed tight and the lining was abcessed (due to this?)

It was a disgusting sight and I imagine the hen must have been very uncomfortable before she died ( do not know if this is what actually killed her, but it cannot have been a good thing!).

Yes, I have Flubenvet ready to hand (when I did it before I found it a bit of a palaver to begin with, with the weighing etc because I suppose it's designed for larger flocks of birds, but once the stuff was measured and weighed it was fine.) Have kept an eye on the colour of the comb, droppings etc which seem to be normal, but I think it's a good suggestion and will get it sorted today. (And will try to remember to do it twice next year!) I sat on a chair in the garden last night so that the chickens would jump onto my lap - I got quite muddy but I wanted to check for external parasites too, but again the poorly chicken seemed to be clear. She seems to have lost a bit of weight though, which might confirm the worm suggestion.
The chicken PM is a gross story but a good cautionary tale... (good job I wasn't eating breakfast when I read it!)

Good news - two proper eggs laid yesterday for the first time in ages, so things are getting back to normal.

Good! Did you worm them? or was it just " one of those things.."

No, I did worm them (well, they're halfway through their week of it - sad recriminating glances from them because they can't have any treats....!!) and I'm sure that has helped.

Well, after laying for a week the chicken stopped again. I wasn't too worried because she was bright and perky (and is starting to moult I think). But today she laid an egg after five days or so without laying which was streaked with blood - she looked a bit down in the mouth and miserable after having been quite happy first thing, and when I picked her up she had blood around the vent. I was going to clean her up but when I looked closely she had all kinds of stuff leaking out, so I took her straight round to the vet. He's not really sure what the matter is - he ruled out peritonitis and a few other viral things because it doesn't look like it, and thinks it must be some sort of localised infection (but quite nasty). He gave her a shot of antibiotic, and I have some tablets to give her next week, and we'll just have to see. Poor Mary....

When the vet showed us how to give a pill to the chicken I'm sure he began by saying 'It's quite easy'. Hmmmmmm!!!!

Grind it up and mash it into her favourite food, or mix the powder with a bit of water and syringe it in...

he should have given you liquid, much easier!

Hope she is recovering.

Perhaps I could stick it inside a raspberry - she's still eating those, and a bit of bread and milk, but she's very sorry for herself

Yep - I stuck the pill inside a raspberry and the chicken couldn't wait to gobble it down!! Thanks CW
The chicken is looking a lot better - I have expected to lose her for the past two days but I think she's bouncing back.