NAVLE Practice Test 13

During a drought, a cow-calf producer begins feeding hay baled from a heavily fertilized oat field. Within 6 hours, 4 of 30 pregnant cows are found dead, and others are weak, trembling, and breathing rapidly with their mouths open. An affected cow has a temperature of 101.8°F (38.8°C), heart rate 120 beats/min, and respiratory rate 80 breaths/min. Her mucous membranes are brown, and blood collected by venipuncture is chocolate brown and stays that color when exposed to air. Which of the following is the most likely diagnosis?