Sometimes disease or trauma will cause a pigeon's Beak to cross over in a scissored effect. When this happens the pigeon can still pick up seed initially , but the upper beak will keep growing and will either need to be trimmed (as illustrated in the paragraph above this one) or to break naturally if the pigeons is to be able to continue
Sometimes a pigeon's upper beak will longer than it should, usually in a downward curve or a hook. This will eventually make picking up seed impossible and the pigeon will starve.
Beaks can be trimmed or filed to a more acceptable length, but trimming too far back can cause a serious bleed so trim off a tiny bit at a time
On white beaks identifying how much can be trimmed safely is relatively simple as the overgrown bit will be transparent making it easy to see where the blood supply starts , but in dark beaks it is much more difficult and it would be best to ask a veterinary nurse to do the job.
If you plan to trim a beak yourself have a supply of Cornflour ready and dip the beak in it if it starts to bleed and trim off a tiny bit at a time.
File down any rough bits. The trimmed beak is likely to overgrow again so pigeons with this condition would be better kept as pets or placed in the permanent care of a sanctuary.
Sometimes trauma will bend the upper beak backward into the throat and it will appear to be broken off, often the tip of the beak will cut through the lower beak and be visible.
In these situations you can gently manoeuvre the beak back into position.
This is very likely to be pigeon pox. It is a pigeon specific virus and does not affect humans but can spread between pigeons via saliva in shared drinking water , shared baths or through beak to beak fighting or via a bloodsucking insects such as the mosquito.
The disease can be mild and self limiting in feral and racing pigeons, although sometimes they are so badly affected that they can't eat and sometimes can't see, so they need supportive care while the disease runs its course. The internal form is more serious, recognised by yellow deposits in the mouth that resemble trichomoniasis (canker) and often results in death. This picture shows a pigeon with internal pox..in this case easily distinguished from canker because it is at the very front of the beak, a area that is too inhospitable for the canker organism to survive.In wood pigeons the disease is more serious, often becoming internal , affecting juveniles that have not yet developed a strong immune system, most often in autumn.