Yes that does look like Croyza. I found this info. If you can find this medication it might work. So sorry to see her like that.
TREATMENT AND CONTROL:
Flock medication with a sulfonamide or antibiotic is recommended. Various sulfonamides -- sulfadimethoxine (SDM), sulfaqumnline (SQ), sulfamet hazine (sulmet) are all effective; however, sulfadimethoxine is the safest and the one prescribed as treatment of choice. SQ and Sulmet are more toxic and require intermittent administration. Therapy in the drinking water will give more immediate response and reduce the severity of the disease. Feed administration of the sulfa or antibiotic does extend the period of treatment for better control. A combination treatment approach is advisable. Administer medication in the drinking water until medicated feed can be provided. Antibiotics that are beneficial include tetracycline, erythromycin, spectihomycin and tylosin. All are safe and approved for use in poultry. Control cannot be accomplished with drugs alone. Management is equally important. A bacterin is available that can be used in a control or eradication program. The bacterin requires multiple injections to be effective which makes it costly and cumbersome for commercial flocks. Control requires attention to flock sanitation, biosecurity, preventive medication, clean and sanitary premises, and disease-free replacements.
