610 



PHTHIRIA8IS. 



These parasites, whose powers of increase are astonishing, keep the 

 patients in a continual state of irritation, causing them to lose con- 

 dition and, in the absence of treatment, to die of exhaustion. 



The diagnosis is very easy, the parasites being visible to the naked eye. 



The prognosis is not grave unless the condition affects a large 

 number of animals in herds. In young animals the prognosis is much 

 graver, for the little creatures rapidly become anaemic and die in a 

 state of exhaustion. 



Treatment. When the byre, fold, or piggery is infested the first point 

 is to remove the animals and thoroughly disinfect and cleanse all parts. 



Fig. 248. — Sheep foot louse {Hceviatopinus pedalis). 

 view of terminal segment of same, showing brushes ; 



a, Adult female ; b, ventral 

 c, terminal segments of male ; 



d, egg. Enlarged. (After Osborn, 1896; Bui. No. 5, Div. Entomology, Dept. Agr.) 



After the manure has been cleared out, the walls, mangers, racks, 

 etc., are washed with boiling water, or, better still, potash solution, and 

 disinfected first with vaporised sulphurous acid, then, if necessary, with 

 a washing of caustic lime. ' 



The patients are afterwards clipped, washed with soft soap and 

 dressed with anti-parasitic solutions, such as 1 per cent, tobacco juice, 

 or a mixture of equal parts of benzine and oil or benzine and petroleum, 

 etc., which give excellent results. 



A 3 per cent, creolin solution is also a very active anti-parasitic and 

 very easy to use. 



