DISEASES OF ANIMALS 



149 



due to the fact that after the ewes are 

 shorn the ticks migrate at once to the 

 lambs and cause great irritation. In 

 many localities, it has been found desir- 

 able to dip both ewes and lambs imme- 

 diately after shearing in order to get 

 rid of this pest. For this purpose sheep 

 may be dipped in a lime-sulphur solution 

 or any other dip which is commonly 

 recommended for sheep scab. The dip, 

 however, need not be so strong as recom- 

 mended for scab, for the reason that ticks 

 are not under the surface of the skin but 

 simply crawling about in the wool. A 

 weak creolin dip will therefore give 

 quite satisfactory result and sheep need 

 not be held so long in the dip as in the 

 case of scab. Where the tick prevails to 

 an excessive degree it is well to dip the 

 sheep after shearing and also in the fall. 



Bladder worm — Upon examining 

 sheep after slaughter it sometimes occurs 

 that the larval stages or bladder worm 

 form of the tapeworm (Taenia margi- 

 nata) are found in the caul. This is 

 the larval condition of the tapeworm 

 which occurs in the dog but is most fre- 

 quently found in the bladder worm form 

 in sheep and pigs and occasionally in 

 cattle. The vesicle in which the bladder 

 worm occurs is found in all sizes rang- 

 ing from that of a pea to that of a man's 

 fist. The bladder worm is most fre- 

 quently found in the pleura and peri- 

 toneum covering the walls of the body 

 cavities. Since this parasite lives in the 

 adult form in the intestines of dogs it 

 is desirable that dogs be treated at regu- 

 lar intervals with some vermifuge like 

 aloes in order to expel the tapeworms 

 and that all unnecessary dogs be kept 

 away from sheep pastures, since the eggs 

 of tapeworms from dogs may be taken 

 into the stomach of sheep with their 

 feed and thus give rise to an infestation. 

 The bladder worm stage in sheep is us- 

 ually a harmless parasite. It may, when 

 occurring in large numbers, cause death 

 in young animals, but this is quite in- 

 frequent. 



Gid or staggers — This disease is also 

 caused by a bladder worm stage of a 

 tapeworm (Taenia coenurus) which lives 

 in the intestines of dogs. The bladder 

 worm is about the size of hazelnuts and 

 is provided with a thin membrane. It 

 penetrates from the alimentary tract to 

 the brain, where it causes peculiar symp- 

 toms which characterize the disease. 

 Affected sheep have the tendency to turn 

 round and round in a circle toward the 



side of the brain in which the parasite 

 is located. There is practically no treat- 

 ment for this disease, but prevention may 

 be accomplished to a large extent by 

 burying or destroying the head of af- 

 fected sheep so as to prevent the dogs 

 from becoming reinfested from eating 

 the bladder worm stage of the tapeworm. 

 Gid is of common occurrence in Europe, 

 but has not been known in the United 

 States until within the past few years. 

 It has recently been reported from a 

 number of localities in Montana and was 

 observed in the Judith Basin by one of 

 us. In some cases where the bladder 

 worm is located near the top of the head 

 an actual enlargement of the skull may 



110 GID WORM OX SHEEP BRAIN 



take place and the worm may be re- 

 moved by trephining at this point. It 

 should also be remembered that wolves, 

 coyotes, and foxes may be infested with 

 the adult worm and may, therefore, 

 carry infection. 



Fringed tapeworm (Taenia fimlriata) 

 — This is a very common intestinal para- 

 site of sheep, especially in the western 

 states, where it causes extensive financial 

 loss. It is found in a large majority of 

 flocks of sheep throughout the Rocky 

 mountains and in some cases whole car- 

 loads of sheep have been found badly af- 

 fected to the extent of 60 per cent or 

 more. The fringed tapeworm varies 

 from 6 to 8 inches in length and is 

 found in the small intestines and bile 

 ducts. When present in large numbers 

 the lambs are weakened and fail to de- 

 velop or put on fat. The general symp- 

 toms are those of malnutrition and 

 many investigators have believed that 

 excessive infestation by this tapeworm 

 is one of the causes of loco, disease. In 

 the intestines, the tapeworm causes a 

 local irritation and similar effects are 

 produced in the bile ducts in addition 

 to stopping the flow of bile. It is not 

 known how the worm lives from the 

 egg stage until it is again found in the 

 intestines of sheep, but some experi- 

 ments by Curtice indicate that occa- 

 sional infection may take place directly 



