Respiratory distress from perilla mint toxicosis is particularly evident when the animal is...

• A. One year after ingestion of the plant
• B. Two to three months after ingestion of the plant
• C. During exhalation
• D. While standing with its head down

Answer: (C)

Perilla mint toxicosis damages the small airways and causes pulmonary edema due to perilla ketone. When the airways are inflamed and narrowed, exhalation becomes the more difficult phase because air must be forced out through constricted passages. This makes expiratory dyspnea—the distress most evident as the animal breathes out. The onset is acute after grazing on the plant, and the sign isn’t a chronic or position-related issue; the hallmark is trouble during exhalation.