DISEASES OF SHEEP 597 



considerably more poisonous than the leaves or stem. Similar state- 

 ments might be made concerning the larkspurs, loco weeds, and 

 water hemlock. As sheep pull up the bulbs and eat them while graz- 

 ing after a storm, increased mortality from poison plants results. 



A number of serious cases of stock poisoning have occurred after 

 snowstorms. In all cases which were investigated an explanation was 

 found in the fact that other forms of vegetation were covered by the 

 snow and that certain poisonous plants of coarse growth remained 

 standing above the snow. In some of the mountainous basins the 

 tall larkspur grows abundantly and stands at a height of about 2 feet 

 by the 1st of June, when late spring snowstorms are apt to occur. Fre- 

 quent cases of poisoning in cattle, from eating large quantities of 

 the tall larkspur, have been observed under such conditions. It may 

 be doubted whether this plant would be extensively eaten under any 

 other conditions. An occasion was offered to investigate some exten- 

 sive cases of poisoning in sheep during autumn, for which lupine was 

 responsible. In these cases the conditions were the same as in that 

 just discussed. Early fall snowstorms had covered other vegetation, 

 and large quantities of the lupines were still standing. Ordinarily the 

 lupines are not poisonous at this time of the year for the reason that 

 the seeds have fallen off, but during some seasons the seeds are re- 

 tained much longer than usual. 



The feeding habits of sheep and other stock are greatly in- 

 fluenced by the full or empty condition of the stomach. It would 

 seem desirable to adopt a general rule never to turn sheep in a starved 

 or unusually hungry condition upon a range which is known to con- 

 tain poisonous plants in abundance. It requires but a few moments' 

 observation to satisfy one's self that a sheep does not exercise the 

 same care in the choice of forage when very hungry that it does when 

 feeding under ordinary circumstances. The disastrous consequences 

 of neglecting this rule are most frequently experienced while sheep 

 are being snipped long distances by railway. When the sheep 

 are unloaded from the cars at intervals for feeding, they are raven- 

 ously hungry and usually unacquainted with the plants which grow 

 at the place where they are unloaded. A number of very extensive 

 cases of poisoning have been observed under such circumstances. In 

 one case 1,900 sheep died from eating lupine in a ripe condition. 

 The sheep came from another state and were unaccustomed to the 

 character of the vegetation where they were feeding. 



From observations made on the stock ranges of Montana, it is be- 

 lieved that it is impossible to conclude with certainty that sheep 

 learn to avoid all poisonous plants by long acquaintance with a given 

 range. In general, however, it may be said that on any particular 

 range less extensive poisoning occurs among the sheep which are fa- 

 miliar with the range than among strange sheep. This statement 

 may be accepted as true for all plants except loco. The eating of loco 

 plants seems to be a pernicious habit, which spreads rather than de- 

 creases among the sheep which are acquainted with the range. 



The actual condition of the vegetation in a given locality also 

 exercises considerable influence upon the extent of poisoning which 



