248 VETERINARY HYGIENE 



of incubation was 8 to 42 days. It would appear, however, that 

 symptoms frequently arise as early as the 5th day following this 

 operation.* 



The mortality is somewhat uncertain. Wallis-Hoare says 

 " that it is estimated to be from 70 to 80 per cent." It is certain, 

 however, that in young animals, and especially lambs, it may be as 

 high as 95 to 100 per cent. According to Nocard the only cases 

 which recover are those in which progress is slow to begin with, 

 though by no means all chronic cases recover. Death usually 

 occurs in 3 to 10 days after the appearance of symptoms, and 

 the prognosis is decidedly more hopeful if cases survive the second 

 week. In general it may be said that the course of the disease is 

 variable. 



PREVENTIVE MEASURES. Suitable surgical treatment of soiled, 

 and especially of punctured and lacerated wounds, aseptic surgery 

 and careful application of the actual cautery are obviously indicated. 

 Frequent flushing of wounds with any oxidising antiseptic, e.g., 

 hydrogen peroxide, is indicated. The pricking of horses by smiths 

 should always be reported by them to the person in charge of the 

 horse, when appropriate surgical treatment can be applied. Care 

 should of course be taken that the sterilization of instruments and 

 suture material is complete, though surgical tetanus is far more 

 rare than accidental tetanus. Newly born and freshly castrated 

 animals should be turned into houses in which by means of clean 

 bedding risk of soil contamination of their wounds is reduced to a 

 minimum. In localities in which cases of tetanus frequently occur 

 injections of antitetanic serum should be made whenever it appears 

 likely that a case may occur, e.g., after operations. 



One attack does not produce immunity, and renewed infection 

 results in the reappearance of symptoms. A very efficient anti- 

 toxic serum is available for the prevention of tetanus. The serum 

 is prepared from horses, the principle being to inject gradually 

 increasing doses of toxin at frequent intervals. Roux and Vaillard 

 commenced the process of hyperimmunisation by injecting toxin 

 which had been attenuated by treatment with a slightly iodised 

 solution (Lugol's solution) followed by increasing doses of pure 

 toxin. In the later stages of hyperimmunisation the horse can 

 often stand an injection of 250 to 300 cc. of toxin, which according 

 to Nocard would be sufficient to kill 2500 untreated horses. While 

 the serum is of very great value as a prophylactic, it appears to be 

 of no great service once symptoms have appeared. Nocard f was 

 * References to Cadiot, Hoffman and Dieudonne see Hutyra and Marek, 



Spec. Path., Vol. I., p. 449, Trans, 

 t Hutyra and Marek, Spec. Path., Vol. I., p. 462, Trans. 



