Hi Tigger
Sorry I missed this thread
It seems that things have been taken care of, however it would have been better to take it straight to your nearest vets. Most vets will NOT charge for seeing wildlife and it may have stood a chance.
We have many pigeons coming into the centre all year round, and at this time of year it could well have been a disease called Trichomoniasis.
It is a disease that grows in the pigeons throat and crop, it is transmissable to other pigeons, usually adults pass it on to their young when feeding crop milk. Pigeons nest all year round, so be aware that there may be others with the same problem in the area.
Only yesterday we had 3 wood pigeons and 1 dove in with trich and all the Wood pigeons had to be put to sleep. The dove however wasn't as advanced and with medication is doing very well.
If your pigeon was thin, had dribbling and lesions around the mouth and a particularly nasty odour then it was more than likely trich. The fact that cats may have caught it is a secondary problem. The more the disease progresses, the weaker and thinner the bird will become. The lesions grow quickly in the crop, throat and mouth, slowly blocking the ability to eat or drink. It some severe cases it actually stops the bird breathing.
The advice to double bag the corpse is a good one, but either bury it deep or take it to a Vets for disposal. Anything (including if it is dumped on landfill sites) can tear the bags open and become infected.
Also it would be wise to disinfect and clean daily all your feeding stations and water containers as, I said before, it is transmissable.
Keep an eye out for other birds with a similar description as if caught early enough you can cure this disease.
Jo