i] Introduction 7 



examined by a competent botanist. Harmful plants should be eradi- 

 cated and their place filled by better herbage. 



Treatment of Poisoned Animals. This volume makes no pretensions 

 to deal with the veterinary treatment of cases of plant poisoning. 

 Whenever poisoning is suspected the services of a veterinary surgeon 

 should be sought without delay ; the text books at his disposal will aid 

 him in the treatment of any case which presents unusual difficulties. 

 The symptoms indicated in the following pages, together with the 

 possible discovery of a suspected plant, may be utilised in diagnosis. 



Tests with Suspected Plants. The action of plants on animals 

 may be ascertained (1) by observing the effects in cases in which it has 

 been estabhshed that the plants have been eaten, or (2) by direct experi- 

 mental feeding of animals with the plant. In the first case the results 

 may be accurate and satisfactory if observations have been made 

 from the outset. 



As regards (2) the results may or may not be satisfactory according 

 as the plan pursued is sound or otherwise. For example, it cannot be 

 considered altogether reasonable and satisfactory to extract the prin- 

 ciples present in the plant, inject them into the blood stream, and con- 

 clude from any ill effects that the animal may exhibit that the plant is 

 poisonous, since the substance extracted may be poisonous under such 

 conditions but little or not at all harmful when the plant is eaten in the 

 small quantities commonly taken by animals. Again, it cannot be 

 held satisfactory to feed an animal on a heavy and exclusive diet of the 

 suspected plant for a considerable period. The real test would, in 

 general, consist in a feeding trial in which the suspected plant occupied 

 a place in the ration in reasonable quantity — such a quantity as might 

 well be taken in natural circumstances, in view of its relative abundance 

 in regard to other food available ; and if considered likely that the plant 

 would be eaten daily it may be fed regularly for some days. Should 

 such a test prove negative it may generally be held that the plant is not 

 poisonous, or only so in exceptional circumstances. 



Legal Aspect of Plant Poisoning. There is clearly some legal 

 liabiHty in regard to poisonous plants which may, by hanging over a 

 boundary, cause injury to a neighbour's stock. The only cases known 

 to the author are in relation to the yew. In the case of Crowhurst v. 

 Amersham Burial Board (48 L. J., Ex. 109; 4 Ex. D., 5) a Burial 

 Board was held liable for the loss of a horse poisoned by eating leaves 

 of a yew tree planted in the cemetery owned by the Board, the tree 

 having grown through and over their fence and projected on to the 



