THE TAPEWORM LARV^ 209 



to ten days. They then subside, and, during a following latent period 

 of four to six months, it is only by close observation that anything 

 abnormal about the animal can be detected. The ocular disturbances 

 already referred to then appear; the head is held in a peculiar position, 

 and the animal turns in cii'cles or it may stagger and stumble about, 

 repeatedly falling. The movements are made in an impulsive manner, 

 with feet lifted high, and the turning may be to the right or to the left, 

 usually toward the side on which the brain is compressed. Other move- 

 ments than turning may be exhibited, and, in fact, their character will 

 depend upon the part of the brain affected by the cyst. 



These symptoms are not continuous, appearing several times during 

 the day with intervals of comparative repose. In three to six weeks 

 from their onset the animal passes into a state of complete paralysis 

 and dies from exhaustion, or it may be in convulsions. 



Such characteristic phenomena of gid are of the final stage, and are 

 due to the pressure of the fully developed ccenurus upon the brain and, 

 in part also, to direct irritation from the booklets of the partly evag- 

 inated larval tapeworm heads. It is only at this stage that the turning 

 movements appear, therefore the disease does not truly merit the name 

 of gid or turnsickness until these manifestations are reached. 



In gid of the spinal cord the parasite is usually located in the lumbar 

 region. The chief symptom is a gradually increasing weakness and 

 paralysis of the hind quarters (hydatid paraplegia). The bladder and 

 rectum become involved and the animal becomes progressively weaker 

 and emaciated. Death occurs in general debility and exhaustion after 

 a course of one to three months. 



The symptoms of gid in other animals are of the same general char- 

 acter as those in sheep. 



Control. — Reviewing the knowledge possessed as to the etiology of 

 gid, the measures to be followed for its eradication are suggested. 

 Chance infection of dogs by the tapeworm should be removed by burn- 

 ing the heads harboring the cysts, or by cooking the affected brains if 

 they are to be fed to these animals. Dogs kept in the vicinity of animals 

 susceptible to gid should be given tseniafuge treatment every three 

 months (p. 186). During the operation of this treatment they should 

 be confined and the expelled worms, fragments, and feces collected and 

 burned or deeply buried. 



Gid is a further contribution to the accumulating reasons why un- 

 cared for and unnecessary dogs — numerically limitless in most commu- 

 nities — should be destroyed. 



Treatment. — On account of the inaccessible location of the parasites, 

 treatment, except by surgical ineans, is useless. The operative measure 

 consists in trephining the cranial cavity and removing the ccenurus, 

 but this can only be advised as practical in the case of animals having 



