[Sassy]

The breed of chicken will also have an effect on their hardiness. Some are better than others

[Silkychicks]

Sassy, yes I guess so.. The Dutch mini-ones are quite tough that's why most farms have these of the large brown ones: many eggs, little maintenance (can you say maintenance for chickens or would that be more for a... tractor??)

Maybe it also depends on how much was done to get a certain look. I read that the silkies where a half sized chicken to start with. They where crossed with other kinds to reduce their size but for example for the feathers they didn't need to go on and on with crossing..
I was told the silky is a strong chicken, but this is new for me so... we'll see.

An Update on Truus:
I phoned the vet on monday about her breathing and about vaccination plus worms..
Related to the breating we spoke about worms and straw and hay.. It was good to change the layer in the pen and he advised me to give it some time. I discibed her behaviour and he said she sounds fine. 
So we agreed to keep the attention to her and see if she would start opening her beak to breath, to her poo and to her appatite and I would phone again a few days later. This was today:
Her breathing has improved since last week. I can still see it, but it doesn't look like she is working anymore. She seems relaxed when she is lying down. I let them free-range through my garden which improved the relationship between the two ladies; which was a bit of an item as well.
The poos look good: no red bits anymore, she eats, drinks, runs, pesters Ad so we figured she is fine. She had a problem with the straw.
I will keep my attention to both of them (which I do anyway) and will drop by when someting strange happens or I can phone.

Here chickens are only vaccinated when they are to 'travel about' whatever reason. So I wouldn't need to vaccinate Truus and Ad anyway.
Worms: there are people with ... 'chickens for shows' who worm every so often. The vet advised me not to.. I'm not sure if I will follow his advise: I worm my cat every so often so why not my chickens... Because the cat doesn't lay eggs that I eat?? I don't know yet.
The stalosan F: I really have read more about a dutch variety to that.

Thank you all for thinking with me and advising me. I have learned a lot from you..

[ANHBUC]

Glad things have improved.  You can call it maintenance for both chickens and tractors.

Over here we have to worm when we have pigeons and other wild birds pooing in the same area the poultry forage.  They can pick up the worm eggs from the poo. 

[Silkychicks]

That is a good reason to worm ANHBUC..

My doubt is that (don't laugh or shout at me   ) I try to keep the hens (eggs actually) organic.. But, offcourse there shouldn't be any discomfort or disadvantage to their health..
I know my vet as a 'don't fuss when you don't need to' vet (that is also why I like him). But I also know that farmers can be a bit, well.. like my father:' it's a chicken, just leave it to that' not meaning they care less and maybe he has adapted to that as well but keeping animals on really small scale in a city, close to home; they become a sort of pet.

If you worm every 3 months, does this mean the stuff stays in the system for 3 months and does it leave the system throug poo and eggs? (Will I be wormed?  ) Do people eat the eggs when the chickens are wormded?

Have you any idea how this works?

[joyfull]

if you use flubenvet to worm you can still eat their eggs. This will remove all types of worms that the birds can get and is a course of 7 days. It doesn't stay in their system once they have finished their course, you simple use again in 3 - 4 months which will catch any new ones that they may have picked up but doesn't leave them too long so they don't get a big worm build up