Intestinal Parasites of the Dog. 303 



Taenia Coenurus (Kuch.). This parasite lives in the small 

 intestine of dog, fox and wolf, and is often quite common in 

 sheep-breeding districts, the larva or scolex having its habitat in 

 the brain or spinal cord of lambs or yearling sheep, and less fre- 

 quently in the young of other ruminants. When mature and 

 discharging ripe segments the taenia may measure 40 inches long. 

 The tetragonal head is followed by an attenuated neck with 

 scarcely a sign of segmentation, yet the caudal, ripe segments at- 

 tain a length of three times their width (5 mm. by 18 mm.). 

 The proboscis bears a double row of 22 to 32 hooks 100 /x to 160 /w, 

 long. The handle of the longer hooks just exceeds the blade in 

 length, while in the smaller hooks it is decidedly longer than the 

 blade. The oviducts have numerous_branches running mainly 

 parallel to the length of the segment. Genital pore, marginal, 

 dilated, slightly projecting. Ova nearly spherical, 34/11, with 

 transparent envelope. 



Coenurus Cerebrales (Kuch.). The larva of T' Coenurus in- 

 habits the cerebro-spinal cavity of lambs, yearling sheep and ex- 

 ceptionally other domestic herbivora, causing the disease known 

 as "gid," " turnsick " or " waterbrain." As in the case of 

 Ccenurus Serialis, the ovum from the ripe segment in the dog's 

 faeces, having hatched out the six-hooked embryo, the latter 

 migrates to its suitable habitat and there develops into a cyst 

 which may exceed a hen's egg in size. This parent cyst devel- 

 ops scolices to the number of 100 to 200 which are individually 

 little larger than a millet seed, but each shows the head of a 

 future tape- worm, and matures as such if the brain which har- 

 bors it is eaten by a dog. The development is slow. In two 

 lambs fed proglottides by Baillet, the .symptoms of "gid" ap- 

 peared in one on the 68th and in the other on the 1 14th day, yet 

 the one showed at the necropsy 33, and the other five coenuri in 

 difEerent stages of development. 



On the eighth day after feeding proglottis, points of congestion 

 are observed in the brain. From the fourteenth to the thirty- 

 eighth day the surface of the brain is marked by pale, yellowish 

 tortuous canals, and near the end of each a cyst y^ i"'^h in diam- 

 eter. By the thirty-eighth day the cyst may be as large as a 

 cherry, and minute depressions on its surface mark the first step 

 toward the formation of the head of the scolex. By the fifty- 



