1010 VETERINAEY HYGIENE 



during their life had been well cared for and not over- 

 worked ; for this reason the thoroughbred stallion was 

 selected, and the age obtained from the ' Stud Book.' The 

 mean age at death from natural causes was 17"34 years. 

 The mean age of those destroyed (old age, broken legs, etc.) 

 was 22"84 years. 



The probable duration of life is about 18"29 years. In 

 the figures examined, the extremes were 5 years and 33 

 years. 



From the elaborate article by Dr. Balfour,* which we 

 have previously had occasion to refer to, we can obtain 

 much information respecting the age at death of working 

 horses (the observations are from the records of the French 

 Cavalry). The highest mortality occurs at 4 years of age, 

 and decreases till 11, when it reaches the minimum. The 

 chief deaths occur at 4, 5, and 6 years of age. More mares 

 die than horses — the excess is equal to 4^ per 1,000 ; on 

 the other hand, 11 per 1,000 more horses are cast than 

 mares. The total loss of geldings over mares is 6J per 

 1,000 greater. 



Castings. — The chief cause of casting is for worn-out legs 

 2-8 per cent. ; incurable lameness 1 per cent. ; broken wind 

 5 per cent. ; old age, 18"4 per cent. 



Influence of Season. — More horses are sick in April, May, 

 and June, and fewer in October, November, and December, 

 Diseases of the lungs are most frequent during the second 

 quarter of the year. Strangles is most frequent in the 

 second quarter, and least in the fourth. Diseases of the 

 bowels are more frequent during the third quarter, and least 

 during the first quarter of the year. 



It must be remembered that these results are from French 

 Army horses. Climate, breed, stable management, and many 

 other points may cause them to differ from what occurs in 

 the United Kingdom. 



The period for tvhich horses ivill stand work in civil life 

 varies with its nature. Cab-horses work for about 2 or 3 



* 'Vital Statistics of Cavalry Horses,' Journal of the Statistical 

 Society, June, 1880. 



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