DISEASES OF ANIMALS 



163 



ries are small, oval organs varying in size 

 up to that of a walnut and lying just at 

 the ends of the horns of the uterus. 

 They may be most conveniently found 

 by following these organs with the hand. 

 On the range, cattle to be spayed may be 

 roped and thrown, or driven into a chute 

 designed for holding the animals firmly. 

 An opening may then be made in the 

 right side, about half way between the 

 last rib and the prominence of the hip 

 bone. Care should be taken to make 

 the cut with a knife provided with a 

 guarded-blade so as to avoid all danger 

 of cutting the intestines. The hand 

 is then inserted and as soon as an ovary 

 is found, the ligament connecting it with 

 the abdominal wall is cut with scissors, 

 knife or ecraseur and the ovary is re- 

 moved. The other ovary must then be 

 removed in the same way. This opera- 

 tion is done by veterinarians with ob- 

 servance of proper sanitary precautions, 

 after washing the hands and the knife 

 in an antiseptic solution. On cattle 

 ranges, however, the operation is very 

 quickly performed by cowboys, who re- 

 ceive from 25 to 50 cents per head. 

 These men pay no attention to antisep- 

 tic conditions, but simply wash their 

 arms and knives in a bucket of water 

 and stitch up the cut in the body wall 

 with coarse twine. Many veterinarians 

 prefer to remove the ovaries through an 

 opening in the wall of the vagina and 

 this method is adopted most frequently 

 in the case of mares. The operation may 

 then be done with the mare in a stand- 

 ing position, confined in a chute. In 

 such operations the ovarian ligaments 

 are crushed off by an ecraseur and great 

 care is taken to avoid mistaking a fold 

 of the intestines with its contents for an 

 ovary. Mares and bitches should be 

 spayed only by skillful veterinarians or 

 expert operators, since there is consider- 

 able danger of abdominal infection un- 

 less antiseptic precautions are observed. 



ARTIFICIAL IMPREGNATION 



During recent years an unusual in- 

 terest has been developed in the artificial 

 impregnation of our domestic animals. 

 Several purposes are served by this op- 

 eration. As is well known, some mares 

 and cows may remain permanently ster- 

 ile, despite repeated service by the stal- 

 lion or bull, but in some cases this ster- 

 ility is due entirely to the malformation 

 of the uterus, particularly a closure of 

 the neck of this organ. Artificial im- 



pregnation or insemination was first 

 adopted to treat such cases. It was 

 found that by dilating the neck of the 

 uterus slightly with the finger or a 

 metallic instrument, the opening could 

 be enlarged sufficiently to permit the in- 

 troduction of a syringe into which the 

 semen had been drawn after service, and 

 by means of which the semen could be 

 introduced directly into the uterus, thus 

 producing pregnancy. 



Later the method of artificial inpreg- 

 nation acquired a much greater impor- 

 tance by its extended use on horse farms 

 and to some extent on cattle farms. It 

 was found that frequently a number of 

 mares would be in heat at the same time, 

 and where it was desired to use the 

 same stallion on all mares, the ser- 

 vice was severe on the stallion and in 

 some cases, led to the production of 

 weak colts. Resort was therefore had to 

 artificial impregnation to increase the 

 efficiency of the stallion. Several methods 

 have been adopted. Some breeders pre- 

 fer to attach a so-called breeding bag 

 to the penis of the stallion before service, 

 after which the semen is drawn into a 

 syringe commonly known as an impreg- 

 nator, and may then be injected into a 

 number of mares. A sufficient quantity 

 of semen is readily obtained from one 

 service to impregnate six or more 

 mares. Occasionally an objection is 

 made to the use of the breeding-bag 

 and if this is the case the horse is al- 

 lowed to serve a mare, after which the 

 artificial impregnator is introduced into 

 the vagina and the semen drawn into 

 it and used as just described. In order 

 to prevent a large proportion of the se- 

 men from being discharged directly in- 

 to the uterus of the mare served by the 

 stallion, a rubber plug has been devised 

 for obstructing the entrance to the ute- 

 rus. After service the plug is removed 

 and a small quantity of semen intro- 

 duced into the uterus. 



A number of dealers in veterinary in- 

 struments have devised special syringes 

 or artificial impregnators which differ 

 considerably in their shape and construc- 

 tion. According to the extended observa- 

 tions and experiments of Lewis, in Okla- 

 homa, the curved metallic impregnator 

 is more satisfactory than one consisting 

 of a rubber bulb, rubber tube and a can- 

 ula which is introduced into the uterus. 



The capsule method op artificial im- 

 pregnation also has its champions. This 

 method consists in simply using small 



