38 MISCELLANEOUS PAPEES. 



poison horses, sheep, and cattle and that Astragalus mollissimus 

 would poison horses. Astragalus mollissimus does not poison cattle 

 because they very rarely eat it. 



The work of the second season, the summer of 1906, was mainly de- 

 voted to a diagnosis of the disease. The external symptoms de- 

 scribed by stockmen were in general corroborated. The principal 

 symptoms are the lowered head, rough coat, slow, staggering gait, 

 movements showing lack of muscular coordination, sometimes more 

 or less paralytic symptoms, a generally diseased nervous system, and 

 in the later stages of the disease extreme emaciation. 



The principal pathological changes are pronounced anemia of 

 the whole system, diseased stomach walls, and in acute cases a con- 

 gested condition of the walls of the stomach, while in chronic cases 

 there are frequently ulcers. Generally speaking, locoed cattle have 

 ulcers in the fourth stomach. There is an excess of fluids in the 

 various cavities of the body. This is especially noticeable in the 

 epidural space of the spinal canal. Here the effusion is more or less 

 organized, presenting the appearance of a gelatinous mass, which is 

 especially abundant in the lumbar region and about the exits of the 

 spinal nerves. In most locoed females the ovaries are found in a 

 diseased condition. 



The third stage of the work was the devising of remedial measures. 

 This was undertaken in the summer of 1907. This work naturally 

 had two phases. (1) attempts to eradicate the weed and (2) attempts 

 to cure the locoed animals. 



In regard to the possibility of killing the weeds, it was found that 

 this could readily be done in the case of fenced pastures. This is 

 especially feasible with Astragalus mollissimus, because it occurs in 

 comparatively small patches. Aragallus lamherti has a wider distri- 

 bution, but it is not at all impossible to destroy this weed when in 

 pastures. There seems to be no way of ridding the ranges of these 

 weeds, however. 



In regard to the second phase of remedial work, it was found that 

 locoed cattle can in most cases be cured by a course of treatment with 

 strychnine, while locoed horses can generally be cured by a course of 

 treatment with Fowler's solution. The animals under treatment 

 must not be allowed to eat the loco weed and should be given not only 

 nutritious food but, so far as possible, food with laxative properties. 

 To this end magnesium sulphate was administered to correct the con- 

 stipation which is almost universal among locoed animals. It should 

 be noted, too, that magnesium sulphate may serve to some extent as 

 an antidote to the poison. 



It may be added, in regard to the question of immunity, that loco 

 poisoning comes on in a slow and cumulative manner, so that there 

 is no possibility of animals becoming immune. 



121— ill 



