animals lose their appetite from the first, begin to emaciate, and show symptoms of malnutrition and starvation. The head trembles, the gait becomes feeble and uncertain, the eyes become sunken and have a “flat, glassy look.”[30] There is a general sluggishness, muscular incoordination, and difficulty in motion; finally all control of the limbs is lost and the animal is unable to stand; the coat becomes rough and loses its luster, and, in fact, all the typical symptoms of starvation appear. In some cases diarrhea is also present.

All of Nockolds’s animals, however, were constipated and the stools were covered with mucus.[31] The dependent portions of the body may swell, simply as an expression of the anæmia.[32] Sometimes there are symptoms indicating acute pain,[33] the animals running about as if affected with colic. They may belch and their abdomens swell. Some claim that the animals are markedly salivated so that the saliva trickles from their mouths. In other cases the mouth may be dry.[34] The eyes may be rolled up so that the whites alone show. In some cases the pupil has been noted to be dilated, as in atropine poisoning,[35] but Wilcox states that they are contracted as after the use of eserine.[36] The temperature of the animal falls from 1/2 degree to 1-1/2 degrees F. below normal.[37] Tetanic symptoms may occur,[38] or the muscles of the mouth and tongue becoming paralyzed may interfere with mastication. When water is offered to the animal, it gazes stupidly at it and may not drink for days. One of the symptoms noted is the loss of power to back properly.[39] Cows during the first two or three months of gestation are almost sure to abort.[40] This is claimed by Knowles, however, to be due to malnutrition. As a result of these observations, suggesting some uterine action, the drug has been proposed as an emmenagogue.[41]

The psychical symptoms are shown by errors of judgment. The animal becomes dull and spiritless and wanders about half dazed. The mental dullness passes into stupor. This dull, stupid condition has been compared to intoxication with opium. If the locoed horse is led across a stick lying on the ground he often jumps high as if it were a great obstacle. The animal may now have maniacal attacks, during which he rears and may fall backward,[42] and makes unreasonable jumps and other unexpected movements, thus rendering himself dangerous to man.[43] Other symptoms due to disturbances of the central nervous system are hallucinations of various sorts. Though the optic nerve itself is apparently not affected, the animal will stare at an object for a long time without any apparent comprehension of its nature. This disturbance in the visual function McCullaugh claims to be one of the first symptoms of this disease. The animal seems to lose all idea of distance, as he will butt against an obstruction as if oblivious of its presence. Any sudden or violent motion made before him may cause him to fall. According to some, the animal loses the sense which guides him in finding water. A cow may fail to recognize her calf.[44] There is more or less loss of control of the limbs[45] and tremors;[46] the feet are lifted abnormally high when trotting, and, if crowded, the animal falls headlong and will jump over little hollows as if they were wide ditches.[47] The horse may shy without apparent cause and kick at imaginary objects,[48] and, in fact, the reasoning powers seem to be lost. These attacks are brought on by sudden excitement or when crossing water.[49] There may be cutaneous hyperæsthesia.

The animals may remain with the herd, but they often wander away. Stalker records the following observations:

I have seen a single animal miles away from any other individual of the herd, carefully searching as if for some lost object, and when a loco plant is found he would devour every morsel of it with the greatest relish. As soon as one plant was eaten he would immediately go in search of more, apparently oblivious to everything but the intoxication afforded by his one favorite article of food.