20 VETERINARY HYGIENE 



calves, but Mackenzie has given it as his opinion that the growth of 

 calves is often retarded through their having too little to drink. 

 When their milk has been curtailed they do not eat enough dry food 

 to promote proper growth. Their fluid allowance should be made 

 up to two or three gallons a day, according to their size.* 



Stock frequently suffer from a temporary water shortage when 

 on train transport, though not commonly in this country. By the 

 Water Supply on Railways Order, 1895, railway companies must 

 supply water at certain scheduled stations to all animals carried, or 

 about to be carried, by rail. Animals travelling to market by road 

 in the summer often suffer from thirst. 



THE EFFECT OF SEWAGE-POLLUTED WATER ON ANIMALS. 



A great many cases of illness and death among horses and cattle 

 have been attributed to the animals drinking water polluted with 

 sewage effluent. Many such cases have been taken to the law 

 courts and damages claimed against persons responsible for the 

 pollution, and the claimants have met with a responsive sympathy. 

 It is not a difficult matter to induce a body of jurymen to believe 

 that because water contains a certain percentage of sewage it must be 

 poisonous, and, therefore, the cause of the particular illness from 

 which the animals happen to be suffering. 



Instances of so-called sewage poisoning are usually confined to 

 cattle and horses, and the symptoms said to be manifested most 

 commonly are abortion, diarrhoea, indigestion, general ill health 

 and an unthrifty condition. Sometimes sudden death or death 

 following but a short illness is also recorded as occurring after an 

 animal has drunk from a foul stream or pond. More commonly, 

 however, the disease is of a more prolonged nature, being rather 

 in the nature of general unthriftiness than an actual and obvious 

 disease, but the owner of the animals can usually assert that the 

 symptoms, often of a vague character, began shortly after the 

 particular water was first used. 



The state of our knowledge concerning the effect on animals 

 of drinking sewage-polluted water is not satisfactory. While one 

 is not prepared to say that the drinking of such water by animals 

 cannot cause disease, or at least ill health, no evidence has yet been 

 produced, so far as the author knows, that sewage-polluted water 

 does definitely cause illness. It is extremely improbable that the 

 causal agents of specific animal diseases are conveyed in ordinary 

 sewage, anthrax from effluents from tanneries and wool-washing 

 * Cattle and the Future of Beef Production in England, 1919. 



