REMOVAL OF THORN-HEADED WORMS EROM SWINE 5 



TESTS OF ANTHELMINTICS 



This report covers experiments conducted by one of the authors 

 (H. B. K.), in Chicago, during the period from 1922 to 1928, in- 

 clusive, on the treatment of swine for the removal of the thorn- 

 headed worm, M acracanthorhynchus Mrudinaceus. 



EXPERIMENTAL PROCEDURE 



EXPERIMENT 1 



Carbon Tetrachloride (25 c. c.) 



Fifteen pigs, weighing about 125 pounds each, shipped from 

 Alabama, were used. Fecal examination of 12 of the 15 showed 

 M. Mrudinaceus ova. 



Feed was withheld for 36 hours, and on March 1, 1922, each of 

 the 15 pigs was given 25 c. c. of carbon tetrachloride (CC1 4 ) in 75 

 c. c. of castor oil. All feces were collected, washed, and examined for 

 the entire group, not for each pig separately. Fecal examination 

 from March 2 to March 6 showed for each successive day the follow- 

 ing: 4 thornheads; 5 thornheads, 2 large ascarids, 1 small ascarid 

 (Ascaris swum), and 1 nodular worm (Oesophagostomum dentatum) ; 

 1 thornhead; 2 thornheads. Total worms passed, 12 thornheads, 3 

 ascarids, 1 nodular worm. 



The pigs were slaughtered March 6, and 89 M. Mrudinaceus were 

 found, attached and alive. The swine hookworm, Globocephalus 

 longemucronatus (synonym Orassisoma urosubulatum) , was found 

 in the small intestines in large numbers. Since only 12 thornheads 

 were passed and 89 were found upon post-mortem examination, the 

 carbon tetrachloride was only 11.8 per cent effective against thorn- 

 heads in this experiment. 



EXPERIMENT 2 



Carbon Tetrachloride (32 c. c.) 



Twelve pigs, shipped from the Southwest, weighing from 100 to 

 125 pounds each, were used in this experiment. Instead of a fecal 

 examination of these pigs, a post-mortem examination of 25 pigs 

 from a similar lot was made on the killing floor and the intestines 

 were found to be infested with M. Mrudinaceus; in one pig 58 

 thornheads were counted. 



On March 22, 1922, each of the 12 pigs was given 32 c. c. of carbon 

 tetrachloride in 96 c. c. of castor oil, a metal dosing syringe being 

 used. Feed had been withheld for 36 hours, but by a mistake some 

 corn was thrown into the pen one-half hour before dosing. Fecal 

 examination of the manure from the entire group from March 23 

 to March 30 showed for each successive day the following: No 

 worms; 3 thornheads; 2 thornheads; no worms the last five days. 

 Total worms passed, 5 thornheads. Three pigs died after treatment, 

 one on March 23, probably from injury, another on March 27, 1922, 

 and another on March 28, 1922. These pigs were not examined, 

 and the cause of death was not determined. 



