STAGGERS IN SHEEP IN PATAGONIA

After observations and experimental work both in the field and laboratory, the following conclusions seem justified. 1. Staggers is a non-infectious disorder affecting horses, cattle, and sheep. 2. The disease is characterized by weakness, muscular twitching, irregular movements of the head, stiffness of the limbs, and transient motor paralysis, accompanied with spastic spasms on excitement. There is also a derangement of vision and conjunctivitis. 3. The postmortem lesions are not characteristic. 4. We readily produced the disease by feeding susceptible sheep on a coarse tuft grass commonly known as coiron or pampa grass (Poa argentina). 5. The time required to produce definite symptoms by feeding the grass varied. Two animals developed typical staggers after two feedings; in another instance a period of 21 days of feeding was required. The average time for the production of unmistakable symptoms in our experiments was 10 days. 6. Many sheep recover from staggers spontaneously. A complete change of diet will usually effect a cure within 2 weeks. 7. Older .animals that have pastured for long periods on lands where the grass grows become tolerant and are rarely affected with staggers. 8. The grass is toxic to sheep at all seasons of the year. We fed late winter and early spring grass and grass in flower, and produced staggers in every instance. The young green grass is as toxic as any edible portion of the plant.