Ampicillin 50 % is  used to treat bacterial infections in Pigeons caused by the following pathogens:
Streptococcus
Staphylococcus
Clostridium
Escherichia coli (E. coli)
Salmonella
Klebsiella
Proteus
Haemophilus
Pasteurella
Spiral (possibly referring to Spirochetes, a type of bacteria with a spiral shape)
AMPICILLIN 50% antibiotic is used in Pigeon bacterial infection to include respiratory tract infections, gastrointestinal infections, and other bacterial infections that may affect the health of the birds.
Following proper veterinary diagnosis and prescription is important. 
Always consult with a veterinarian for accurate diagnosis, proper antibiotic selection, and guidance on appropriate use .