Husbandry of poultry is very much ‘by eye’. Only by spending time around your flock will you pick on potential problems as chickens are very good at disguising illness which is quite possibly a survival mechanism to mitigate the risk of predation common in many species of bird.
Sick birds may emerge from the coop in a flurry with the other hens but then spend the day skulking or hiding out of sight, so be sure to do a head count periodically during the daylight and investigate any bird that seems out of sorts.
The nature of many poultry diseases is such that the symptoms can appear more or less the same which can leave you, the keeper, at a loss as to what might be the issue but by carefully observing your flock you can pick up on certain diagnostics that may help isolate the problem.
This BVA Animal Welfare Foundation pdf file was put together in conjunction with the Poultry Club of Great Britain and provides an excellent early diagnostic crib sheet and is well worth downloading and printing off. Stick it on the wall of your chicken shed or feed store and familiarise yourself with the basic symptoms, likely causes and possible treatments.
As mentioned earlier, birds can and do disguise illness, consequently when it becomes obvious that there’s a problem it can often be too late to treat them. Early identification of diseases or disorders therefore can be the difference between life and death.
It goes without saying that the crib sheet provides only a guide but it can be essential in collecting the right information about the problem your bird maybe suffering and this will help immensely should you need to refer to a poultry vet.
If you are a twitter user then its well worth following two such vet establishments on there, namely @avianvets and @chickenvet , or alternatively visit their web sites ( AvianVets and ChickenVet ) as both are frequently available to help and advise the online poultry keeper.