io8 CANINE AND FELINE SURGERY 



dog with a well-marked internal squint in each eye, the pupils appearing 

 to be looking at the nose all the time. The appearance of the animal's 

 face was most ludicrous (see Fig. 76). The deformity was congenital, the 

 animal being then about three years old. No defect of vision had been 

 observed until during the last three months, when the owner stated that 

 the dog appeared to see imperfectly, and when crossing a crowded 

 thoroughfare had been almost run over on one or two occasions ; this 

 latter fact led him to seek professional advice. As the result of operation 

 the condition of one eje was decidedly ameliorated, but in the other there 

 was not much alteration ; the animal, however, became restored to use- 

 fulness as a drover's dog, and the owner noticed a marked improvement 

 in the way it went about its work. 



A second case came under observation in October, 1901, the patient 

 being a well-bred retriever pup, seven months old. This, too, was a con- 

 genital deformity, only the left eye being affected ; there was internal 



F^ig. 77- — Strabismus Hook (Walton's). 



strabismus, and the vision was defective. The internal rectus muscle 

 was cut and the membrana nictitans removed, the result being a marked 

 improvement, although the eyeball never became quite normal. 



Operation. — The operation for the rehef of strabismus is 

 not a difficuh one, although it requires a certain dehcacy of 

 manipulation of the instruments. Either local or general 

 ansesthesia may be used, the latter being preferable, because 

 the head can be kept perfectly still. The object in operating 

 is to divide the muscle, either the external or internal rectus, 

 which is producing the squint. A speculum is applied to the 

 eyelids, and the conjunctiva at the canthus carefully incised 

 with a pair of fine scissors ; a fine blunt hook is passed 

 underneath the rectus muscle, which is divided as near as 

 possible to its insertion into the eN'eball. 



It ma)' also be advantageous, when operating upon the 

 inside, first to remove the membrana nictitans. The eyeball 

 is then pulled outwards or inwards, as the case may be, as 

 far as possible. 



