Chickens with swollen waddles and joints, plus nasal discharge. Which disease is most likely?

Chickens with swollen waddles and joints, plus nasal discharge. Which disease is most likely?

• A. Newcastle disease
• B. Avian influenza
• C. Chlamydiosis/Psittacosis
• D. Infectious bronchitis

Answer: (C)

A systemic bacterial infection that affects mucous membranes and joints best fits this pattern. Chlamydophila psittaci causes psittacosis (chlamydiosis) in birds, and it often presents with nasal discharge and involvement of other mucosal surfaces along with joint inflammation, leading to swollen joints and sometimes facial tissues like wattles. This combination—the rhinitis with polyarthritis—is characteristic of this organism, and it reflects a more generalized infection that can affect multiple organ systems in affected birds. Other viral respiratory diseases in poultry tend to show different primary signs. Newcastle disease often brings neurologic signs or severe systemic illness with high mortality and less emphasis on joint swelling. Avian influenza can cause facial edema and severe respiratory or systemic signs but typically not the peanut‑style joint swelling described. Infectious bronchitis mainly causes respiratory symptoms such as coughing and nasal discharge, with less emphasis on joint involvement. So the observed mix of nasal discharge plus swollen joints points most toward chlamydiosis.

A systemic bacterial infection that affects mucous membranes and joints best fits this pattern. Chlamydophila psittaci causes psittacosis (chlamydiosis) in birds, and it often presents with nasal discharge and involvement of other mucosal surfaces along with joint inflammation, leading to swollen joints and sometimes facial tissues like wattles. This combination—the rhinitis with polyarthritis—is characteristic of this organism, and it reflects a more generalized infection that can affect multiple organ systems in affected birds.

Other viral respiratory diseases in poultry tend to show different primary signs. Newcastle disease often brings neurologic signs or severe systemic illness with high mortality and less emphasis on joint swelling. Avian influenza can cause facial edema and severe respiratory or systemic signs but typically not the peanut‑style joint swelling described. Infectious bronchitis mainly causes respiratory symptoms such as coughing and nasal discharge, with less emphasis on joint involvement. So the observed mix of nasal discharge plus swollen joints points most toward chlamydiosis.