CHAPTER VI 



POISONING FROM OTHER PLANTS. EQUISETOSIS, LOCOISM, AND UJPINOSIS 



Equisetosis. It has been recently proven by direct experimentation that 



the common horsetail (Equisetum arvense) when ingested in 

 sufficient amount, is capable of producing fatal poisoning among horses. This 

 discovery is of great importance since the plant has a wide distribution, and at 

 times is the cause of extensive losses. The common horsetail thrives best in- 

 moist sandy soils or in low, damp meadows, which are not frequently cultivated, 

 and often constitutes a large part of wild hay. The dried plant alone seems 

 to be poisonous. Young horses seem to be the most susceptible. Sheep are 

 supposed to be slightly susceptible although cattle eat the hay in which the plant 

 occurs in large proportion, with impunity. The toxic principle of the plant 

 has not been determined. 



Symptoms. The effects of poisoning from eating horsetail appear at times 

 varying from two to five weeks, depending upon the age of the animal, and 

 the amount of contaminated hay ingested. 



The first symptoms are usually unthriftiness, general bodily weakness and 

 emaciation. The animal seems to have a depraved appetite, preferring the 

 plant to wholesome feed. As the disease progresses the muscular weakness 

 becomes more pronounced, the animal loses muscular control and exhibits in- 

 coordinate movements. During this stage the pulse and temperature are de- 

 pressed, extremities are cold and the visible mucosae are pale. Appetite usually 

 remains good until the end and consciousness is apparently retained. Finally 

 the animal falls, manifests nervous excitement, paroxysms of convulsions appear 

 and death results from exhaustion. In the final stage the pulse becomes ac- 

 celerated and the temperature elevated. 



Hypostatic pneumonia is a frequent complication. 



Treatment. The first step in the treatment is the removal of the cause. 

 A cathartic should be administered to rid the bowels of the irritant and nerve 

 and heart stimulants given to combat the symptoms of depression. In case 

 the patient is unable to stand, it would be advisable to give some support. 

 When the animal is down it becomes necessary to guard against the develop- 

 ment of hypostatic pneumonia. 



Where cases are not too far advanced and appropriate treatment is in- 

 stituted, recovery is the usual result. (Stuhr). 



Stock-poisoning by the loco weed is a frequent and serious con- 



Locoism. dition with which the stock-owners of the western half of the 



United States have to contend. Montana and Colorado, especially, 



sustain heavy annual losses. Similar diseases occur in other parts of the world. 



In Australia other plants of the order Leguiminosae like Gastrolobium produce 



similar symptoms. Maiden * states that the "Nenta Lessertia disease of S. 



Africa is identical with a disease of the Pea-eating animals of Australia and 



i Miscell. Pub, Dept. Agrl. N. S. Wales, 477: 11. 



