21 



THE SCLEROSTOME WORMS OF THE HORSE, 



AND THE EMPLOY^IENT OF THYMOL AS A REMEDY. 



Two species of Sclerostome worms are known as abundant 

 in the horse, namely, Sclerostomum equinum (Miiller) and 

 S. tetracanthum (Dies). Both often produce fatal results, 

 especially the last-named. These species are well known to 

 veterinary surgeons, but I feel confident that two species 

 have been included under the name tetracanthum. Although 

 these armed Sclerostomes have been known for a great many 

 years, it is only recently that treatment has been of any avail. 



During the past two years a number of cases of these 

 vermiceous diseases have been brought to my notice, some 

 in the form of severe epizootic attacks. The results of inves- 

 tigations in these diseases may be briefly summarised as 

 follows. 



There are evidently three worms belonging to the genus 

 Sclerostomum found in the horse, which may be identified 

 by the following general features : — 



S, equinum [armatiuii] (Miiller), red or brownish-red in 

 colour, from 18-50 mm. long, mouth armed with a circle of 

 teeth on the innermost ring, the outermost ring carrying six 

 papillae ; the caudal pouch of male trilobate, posterior ribs 

 trifurcate, middle double, anterior cleft. The female has the 

 tail obtuse. 



S. tetracanthum (Dies), much smaller than the above, vary- 

 ing from 8-16 mm. long, colour white or dirty white, body 

 tapering anteriorly ; mouth circular, with a ring of teeth, 

 outer ring with six papillae ; two tong lateral spine-like bodies 

 a little in front of the termination of the oesophagus ; caudal 

 pouch of male excised on ventral surface, posterior ribs trifur- 

 cate, middle double, anterior cleft. The female has the tail 

 pointed. 



S. ruhrum (N. Sp.j. This worm is very similar in form to 

 the above, but differs from it in several essential features, 

 firstly in colour, it being always red, whilst tetracanthum (at 

 least what I take to be Dies species) is white, secondly the 



