Which of the following is NOT a typical sign of Chlamydia psittaci infection in birds?

• A. Lethargy
• B. Anorexia
• C. Conjunctivitis
• D. Weight gain

Answer: (D)

Chlamydia psittaci infection in birds (psittacosis) typically presents with systemic illness and respiratory/ocular signs rather than any gain in weight. Birds often appear lethargic, have reduced appetite (anorexia), and show conjunctivitis with ocular discharge, sometimes along with nasal discharge and respiratory effort. These signs reflect the infection’s impact on overall health and respiratory pathways, which usually leads to weight loss or poor body condition rather than weight gain. Therefore, weight gain is not a typical sign of this infection, while lethargy, anorexia, and conjunctivitis are.