Treatment of Infectious Coryza in Canaries: Antibiotic Sensitivity and Clinical Outcomes

Introduction: Infectious coryza (IC) is a respiratory disease that affects poultry and other avian species. It is caused by Avibacterium paragallinarum. Common clinical signs of IC include rhinitis, facial swelling, anorexia, and retarded growth in young poultry. Case report: This report delves into a specific outbreak of IC among a herd of 120 ornamental canaries in Iran in February 2021, where 15 canaries succumbed to the disease. The canaries indicated symptoms, such as swollen heads, closed eyes, severe sinusitis, weight loss, loss of appetite, and reduced ovulation. After the necropsy, a clumpy discharge in the eyes and sinuses and minor bleeding were observed in the trachea. Samples from the sinuses of dead canaries were taken to the laboratory (Mashhad, Iran), and it was determined that the bacteria responsible for the deaths belonged to the genus Avibacterium. Avibacterium spp. are slow-growing and require a specific factor, Nicotinamide Adenine Dinucleotide (NAD), for growth. The antibacterial susceptibility of the bacteria was tested using 18 different antibiotics. Based on the results, fosfomycin and amikacin were selected for treatment. The birds were administered oral fosfomycin (160 milligrams per kilogram) and injection amikacin (10 milligrams per kilogram) for 7 consecutive days. However, a recurrence of symptoms was observed a week after the initial treatment (second outbreak), prompting a further 5 days of treatment. The isolate was completely sensitive to fosfomycin, trimethoprim-sulfamethoxazole, vancomycin, penicillin, amikacin, and furazolidone and the bacterium showed intermediate susceptibility to other antibiotics which tested. After 72 hours of treatment, casualties ceased, and clinical symptoms were reduced. Complete resolution of symptoms was observed within a week. In the second outbreak of the disease, no casualties occurred, and the symptoms vanished within 48 hours of initiating treatment. Conclusion: This case report underscored the infection of canaries flock by Avibacterium spp., which was sensitive to fosfomycin and amikacin in laboratory conditions, and and effectively facilitated the recovery of the infected birds in vivo. The antibiotic sensitivity test provided useful information for finding an effective treatment against bacterial infection, emphasizing the significance of collaborating with laboratories for optimal results. Furthermore, continuous monitoring of this isolate is imperative, as it may potentially play a role in upper respiratory disease outbreaks across diverse avian species.