1006 VETEEINAEY HYGIENE 



Here are a few examples of the method of obtaining this 

 information : 



The Admission Bate for sickness is calculated by adding 

 together the total number of admissions for each month, 

 and then by rule of three ascertaining what percentage of 

 the average annual strength this represents. For example : 



The admissions for twelve months are 447 ; 

 The average strength for the year is 597'25 ; 

 Therefore 447 x 100-=-597-25 = 74-84, 



which is the percentage of sick during the year. To state 

 the fact in another way, out of every 100 horses, 74'84 for 

 one reason or another, had been brought under treatment 

 during the year. 



The mortality for the year is ascertained in the same 



way : 



Tlie mortahty being 20, 



The average strength 597'25, 



20 X 100-^597 ■25 = 3'34 per cent, of deaths per annum. 



The Average Daily Number Constantly Sick in Hospital — 

 viz., the Sick Population — is ascertained by adding up the 

 number of days each case was in hospital, including the 

 day of admission and discharge, and dividing the total by 

 365, or 366 for leap year. All cases remaining in hospital 

 from the previous year must be included. 



Or it may be obtained, though with less exactitude, by 

 taking the numbers remaining under treatment at the end 

 of each week or month, and dividing by the number of 

 weeks or months. 



For example, the number remaining under treatment at 

 the end of each month for twelve months equals 478 : 



478-^12 = 39-83 constantly sick; 



The average strength of animals for the year is 597'25 ; 



Therefore 39-83 x 100-^597■25 = 6•66 per cent, constantly sick. 



To find the Average Duration of each Case of Sickness — 

 viz., the average number of days each case was under 

 treatment — multiply the sick population by the number of 

 days in the year, and divide by the number of admissions : 



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