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DISEASES OF THE DOMESTIC ANIMALS 



(3) Venereal Form. — This may occur alone or associated 

 with lip-and-leg disease. The sheath in bucks and wethers, and 

 the penis in bucks are affected. On the sheath, in folds at the 

 margin of skin and mucous membranes, appear yellow spots or 

 ulcers. The ulcers spread until the whole skin surface of the 

 sheath may be an ulcerating mass, angry and swollen. The penis 

 is more rarely involved in bucks. It becomes ulcerated and swollen, 

 and is known as " big pizzle." Clap, syphilis and ulcerated sheath 

 are also synonyms for the venereal form, which is at times very 

 fatal. In ewes the perineum, region under the tail and margin of 

 skin about the vulva may be the seat of the ulceration characteristic 

 of this infection. 



(4) Foot Rot Form. — Ulceration about the feet may occur 

 with or without lip disease. It attacks all ages and both sexes in 

 sheep. The cleft in the foot is first affected by ulceration, more 

 often about the heel. The ulceration bores under the claw and a 

 thin, disagreeable purulent discharge escapes from the fistulous 

 opening under the horny tissue. 



The mortality varies greatly in necrobacillosis. In favorable 

 climate and on good feed, it may be nil. From 10 to 30 per cent 

 of loss has been reported among flocks in different outbreaks and 

 in various localities. 



Treatment.— This may be described under preventive and 

 medical treatment. 



Prevention includes segregation of newly bought animals for 

 two weeks. It includes frequent and careful examination of 

 healthy animals which have been exposed to the disease. It in- 

 cludes thorough disinfection of infected premises and utensils 

 which have been contaminated by infection. The germs of the 

 disease may live several years in the soil, and on. infected material 

 outside the body, providing the conditions are favorable. Freezing, 

 however, will destroy the bacilli, so that infected pastures may be 

 used after a winter with frost. The manure and soil must be 



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