ANIMAL DISEASES, I35 



When sufficiently grown the sows were put to the boar and 

 afterwards placed on their original restricted diets, in order to 

 find out the effect produced on the offspring and on the milk. 

 The sow in Group i gave birth to eight pigs, only one of which 

 lived as long as 5 hours. Marked abnormality was shown in 

 the other pigs. This malformation was particularly pronounced 

 in two cases in which the hind limbs were represented by thin, 

 tail-hke appendages. This sow v/as again put on a diet containing 

 vitamin A (in grass) before being put to the boar, with the result 

 that a normal Utter was produced. The sows in Groups 2 and 3 

 produced litters of normal pigs. 



The experiments have been continued for a further season and 

 an account will in due course be published. The results have 

 again demonstrated the good effect of cod liver oil (supplying 

 \itamin A). The experim.ents also tested the effect produced 

 by the addition of calcium and phosphates to the diet, and the 

 results show the beneficial effect of these substances, provided 

 a sufficient supply of the essential growth-promoting vitamin is 

 present in the diet. 



CHAPTER IX. 



ANIMAL DISEASES. 



Research into animal diseases is carried out mainly at the 

 Royal Veterinary College, London, and at the Veterinary Research 

 Laboratory of the Ministry of Agriculture and Fisheries, New 

 Haw, Weybridge. Worm parasites of animals are investigated 

 at the London School of Tropical Medicine and at the University 

 of Birmingham. This chapter will contain an account of the 

 main lines of research in progress at all four centres, and will 

 also refer to two further investigations which are being carried 

 out by means of special grants. 



Research Institute in Animal Pathology, 



Royal Veterinary College, London. 



The principal diseases which have been under investigation 



during the past year and which are still being studied are' joint-ill 



in foals, contagious abortion in mares, and contagious mastitis 



or inflammation of the udder in cows. 



Joint-ill in Foals. — This term is applied to cases of acute 

 illness in young foals in which one or more of the large joints of 



