more mucky bums

 3 out of my 4 white sussex birds have mucky bums that came on all of a sudden yesterday but the other 1 so far is clear , could it be something they have eaten ?? one of them is slighty quieter then normal but the others are still pretty lively .

they were wormed  2 months ago roughly so i doubt they will need doing just yet , but the one thing i did think about yesterday was that along with my isa brown who has had a mucky bum for a few months now all came from the same place and i assume from the same breeder as these ppl i brought them from dont breed poulty .
i cant be doing with washing 3 or 4 birds every few days so ahs anyone got any ideas on whats causing this , they are all feed layers pellets an now some fresh veg seeing that its now all starting to grow .

p.s cutting the vent feathers how far down to the skin do you go and do u cut a line down from the vent so the poo drops clear of any feathers or just around the vent if anyone has any pics of this done that would be great  dont want to be giving them a bad hair cut .

My hens go squitty when I've fed them too much fresh greens.

My white/light sussex (pure breed ones - can't remember which name goes with the hybrid?) almost always have a mucky bum.  They stayed clean after moulting through the winter but weren't laying, but as they have come back into lay (well occasionally anyway) back have come the mucky bums!

I am glad other people are having this problem... I thought it was just me.  Despite the obvious health issues that it could have been I was stumped as to why they would be dirty. 

I don't know if it helps looby, but mine get mucky bums if I slightly overdo the Biodry. I've learnt to be very careful!!

i am back  on this topic well my white sussex have seemed to of cleared up via the mucky bums but now my maran seems to be slightly dirty i was wandering could it be the lettuce as they havent really had any for quite some time ??  i really wanna get to the bottom of whats causing this .

one of my araucanas had to have her bum washed yesterday on inspection it was just poo but wanted to be sure  ::)i think she may have stopped laying too :(but seems well in herself.Glad im not the only one