Saving Injured Pigeons

Injury from cats:

I would first place him in a secure cage or box with a heating pad set on low or a hot water bottle, and place a towel on top of the heating pad or hot water bottle. Give him some time to warm up, which is especially important since he is injured. Just make sure he does not get too hot and provide him with an area where he can sit if he does, away from the heat.

Cats have lots of bacteria in their mouths and saliva, and when capturing prey, they inflict deep puncture wounds that allow the entrance of bacteria. If you can, I would suggest you bring him to a veterinarian for treatment. You can try to flush out the wounds with a diluted betadine solution and give an antibiotic to help clear up infection:

You can get from Foys Supplies.

I would wait for the pigeon to warm up first before trying to feed him. Just keep an eye on him and notice if he appears more active after warming. Offer it water before you feed it. You should also add a pinch of salt and a pinch of sugar to the water (or use pedialyte) just in case it is dehydrated.