276 



PARASITES OF THE DIGESTIVE APPARATUS. 



of susceptible animals. Nevertheless, external conditions largely favour 

 infestation. The existence of marshes, ponds, and stag- 

 nant water on certain pastures, heavy annual rainfall, 

 the occurrence of wet seasons, etc., favour the existence 

 and growth of embryos, and, as a consequence, the in- 

 festation of animals. 



The symptoms of intestinal helminthiasis are always 

 very vague, whether the victims be oxen, sheep, or goats. 

 They point to the slow and progressive development of 

 a pernicious anaemia, characterised primarily by inter- 

 ference with appetite and digestion, then by anaemia, 

 and finally by cachexia. The patients are dull, lose 

 condition, suffer from depraved appetite, and, during 

 the cachectic period, from diarrhoea, and die in a con- 

 dition of exhaustion. These forms of helminthiasis are 

 much more frequent in sheep than in oxen. 



The diagnosis is only arrived at by discovering 

 parasites in the faeces, or, in those doubtful cases where 

 one has been led to make a microscopic examination 

 of the excrement, by the detection of large numbers 

 of eggs. 



From an economic standpoint the prognosis is grave, 

 because severely infected animals recover their condi- 

 tion very slowly, whatever treatment be adopted. 



Treatment includes the measures previously indi- 

 cated regarding the destruction of germs, eggs, or em- 

 bryos distributed over the pastures, and the drainage of 

 wet grounds and stagnant pools. Where such diseases 

 are common, the pastures should be dressed with iron 

 sulphate, and the stable manure disinfected or burned. 



Curative treatment comprises the administration of 

 such anthelmintics as can be given with the food. They 

 should not require to be administered by force, as this 

 proceeding would not only necessitate a great loss of 

 time, but might result in accidents. 



Arsenious acid, in doses of 15 grains per day, and 

 tartar emetic, in doses of 75 to 150 grains, according to 

 the animal's size, are among the best drugs for oxen, and 

 may be given for four or five days running. Benzine, 

 oil of turpentine, and empyreumatic oil are more diffi- 

 cult to administer. 

 In the case of sheep, preference should be given to areca nut, 

 in doses of 75 to 120 grains, according to the animal's size, and to 



Fig. 118.— Adult 

 specimen of the 

 fringed tape- 

 worm (Thysa- 

 nosotna actini- 

 oides). (After 

 Stiles, 1893.) 



