268 Agricultural Gazette of N.S.W. [April 3, 1920.. 



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Jn naturally occurring cases cattle show symptoms of trouble about two- 

 weeks after commencing to eat the plant. One stockowner says that sheep 

 will begin to show signs within forty-eight hours of being turned into an 

 infested paddock. In experimental feeding, as will be shown, the earliest 

 symptoms were observed in thirteen days ; but during the time over wliich 

 the experiments extended there were a good many dull days, when very little- 

 sunshine was seen. This may perhaps account for the more lengthened 

 period, although dull days should not interfere with the process of sensitis- 

 afion, but only with its manifestation. 



Symptoms observed in the Field. 



Cattle. — In the initial stages the animal shakes its head violently, and 

 frequently the whole body in the same maniier, as if to remove some 

 irritating body. It scratches at its head and other parts of the body with 

 its hoofs, rubs against posts, &c., and at times races about the paddock just 

 as cattle do when attacked by warble Hies, although those flies do not exist 

 in the locality referred to. Before long the animal commences to lick itself op 

 the white-haired places, and very soon this hair is removed and there remains, 

 a raw surface. The aflFected skin swells and becomes very reddened ; the 

 nostrils, when not pigmented, swell up and become covered with scabs, which 

 also form over all the excoriated surfaces after a time. The itching of the 

 skin is sometimes so intolerable that the animal appears to go mad, rushing 

 into waterholes where it tries to bury itself in the water or mud in the- 

 endeavour to relieve the irritation. 



Sheep. — There is considerable reddening and swelling of the skin in 

 general, followed by an exudation of plasma or the fluid portion of the blood. 

 This coagulates in clear yellowish masses, often matting the wool together.. 

 The animal bites at its skin on account of the itching, or i-ubs itself against 

 solid objects, and tlie wool is removed, particularly on the legs, face and 

 loins, these places becoming quite raw and eventually scabbing over. The 

 eyes, ears, lips and nostrils swell up considerably and become covered with 

 scabs, and the ears may become torn into shreds on account of the rubbing, 

 by the animal. The eyes are affected in some instances, the cornea becoming, 

 opaque ; at times total blindness results. Some animals may be seized with 

 a fit, leap up into the air and roll over and over. Certain sheep die very 

 soon after such acute convulsive symptoms are shown, but the majority do 

 not succumb, though they become very poor. In both cattle and sheep loss 

 of condition is a very observable feature ; in milking cows there is total 

 suppression of milk ; and in sheep the interfeience with the normal growth 

 of the wool seriously lowers the value of the fleece. 



Horses. — Not many horses have been observed affected, and such as were 

 showed evidence of it only on parts covered with white skin, genei'ally on the 

 hind legs. Sores are said to break out between the coronet and fetlock- 

 In all animals markedly affected there is great mental depression, the 

 animals being said to mope. The main symptom, however, is itching, and 

 this is always present. There is no doubt that this has given rise to the 



