till' iiroseiioe of Ku^^tro entoiitis; it is luit indicated in the 

 treatment of pregnant mares. 



C.VRBON Tetr^\chix)Kide. This is also an oft'cetive treatment 

 for tlie removal of asearids from horses. It is given in the 

 same manner as for the removal of strongyles, but in heavy 

 asearid infections it is advisable to follow the drug by a 

 saline iiurgative in order to sweep out dead worms and jire 

 vent their oluniiiing in the small intestine. This is particularly 

 indicated in the case of foals. 



PllENOTHiAZlNH. E.xperiments indicate that this drug will 

 remove some asearids but more data are needed before it can 

 be established as a satisfactory treatment. 



TREATMENT FOK THE RE.MOVAI, OF L/VRGE AND S.MAI, I. .STRONGYLES. 

 STRONOYLUS SPP., TRU'HONEMA SPP. AND RELATED GENERA 



Oil OF Chenopodium. Chenopodium is very effeetive for the 

 removal both of large and small strongyles. Aninuils slumld 

 be fasted for 3ti hours and oil of chenopodium administered in 

 a dose of 4 to 5 fluid drams (16 to 20 cc.) for a 1,000 pound 

 animal, or at a dose rate of 1 fluid dram (4 cc.) for each 2.'i0 

 pounds of body weight, immediately preceded or followed by 

 1 quart of raw linseed oil. Cases of excessive jmrgation have 

 been reported in some instances following the use of raw lin- 

 seed oil. It is possible that this undesirable action is due to 

 impurities in the product ; consequently a good grade of oil 

 should be used. Veterinarians' of the V. S. Army have pro- 

 posed a substitute puigative of castor oil and mineral oil, 

 claiming that this mixture provides snitalde purgation fol- 

 lowing treatment with chenopodium and is without undesirable 

 effects. The following are the doses of the mixture recommend- 

 ed: For weanlings, castor oil 4 to 6 ounces and mineral oil 

 1 pint; for yearlings and 2year-olds, castor oil 6 to 8 ounces 

 and mineral oil 1 pint ; for 3-year-olds and older, castor oil 8 

 to 10 ounces and mineral oil 1% pints. Oil of chenopodium is 

 contraindieated in the presence of constipation, gastroenteritis 

 and febrile conditions, and in pregnant mares. 



Carbon Tetrachloride. This drug is effective for the re- 

 moval of large strongyles but only about 50 percent effective 

 against small strongyles. It should be given in capsule or by 

 stomach tube in a dose of 6 to 12 fluid drams (2.'') to 50 cc. ) 

 for a 1,000-pound animal after fasting for 24 to 36 hours. The 

 drug need not be accompanied by a purgative but if one is 

 used, sodium sulphate is to be preferred. If linseed oil is used, 

 it should be given 4 to 5 hours after carbon tetrachloride. The 

 administration of carbon tetrachloride to equines is followed by 

 a fall in the blood calcium level and by a marked increase of 

 bilirubin in the blood. In carbon tetrachloride intoxication, it 

 is advisable to use calcium gluconate. The drug is contrain- 

 dieated in animals suffering from hepatic disease or from cal- 

 cium deficiencies, such as rickets or osteomalacia. 



N-Butylidene Chloride. In a dose of 0.2 cc. per kilogram 

 of body weight, this compound is very effective for the removal 

 both of large and small strongyles. It is probable that the 

 dose could be reduced to 0.15 cc. per kilogram without ma- 

 terially aifecting the efficacy of the treatment; this dose is 

 equivalent approximately to 70 cc. for a 1,000-pound animal. 

 As n-butylidene chloride is constipating, it is advisable to fol- 

 low the drug in 5 hours by raw linseed oil in a dose of 1 quart 

 for a 1,000 pound animal. 



N-BUTYL Chloride. Because of the relatively higher cost 

 of n-butylidene chloride, Harwood, Underwood and Schaffer 

 (1938) tried n-butyl chloride for the removal of strongyles. 

 In a dose of approximately 0.2 cc. per kilogram of body weight, 

 the compound proved very effeetive for the removal of small 

 strongyles and reasonably effective for the removal of large 

 strongyles. In the tests in question, the drug was given in 10 

 times its volume of raw linseed oil. In tests by the above- 

 mentioned workers, two horses succumbed to treatment with 

 doses ten times the therapeutic dose. It would appear that 

 the compound is not as safe as is n-butylidene chloride and that 

 further tests are needed to clarify this point. 



Phenothiazine. This is a very effective drug for the re- 

 moval of strongyles from horses. Several authors have reported 

 excellent results following the use of doses varying from 30 to 

 100 grams for adult animals. However, the only critical ex- 

 periments reported thus far were by Harwood, Habermann, 

 Roberts and Hunt (1940) and Habermann, Harwood and Hunt 

 (1941). In the tests described in the latter paper, it was 

 found that this drug in doses varying from 50 to 100 grams 

 per equine removed practically all of 362,797 cylicostomes and 

 96 percent of 137 Strongyliis spp. These authors concluded 

 that the dose per adult equine should be held at 50 grams 

 pending additional critical experimentation with smaller dos- 

 ages. In some instances, a dose of 50 grams failed to remove 

 a few of the Strongyliis spp. present In the treated animals 

 and, since these are the most pathogenic of the nematodes 

 present in equines, it does not seem advisable to employ dos- 



ages of ;i(i giams per horse such as recommended by Taylor 

 and Sanderson (1!I4I)) on the basis of tests checked by the egg 

 count method alone. 



Single doses of ])henothiazine as high as 500 grams have 

 been given to horses without producing alarming symptoms, 

 but these dosages may cause pronounced cloudy swelling of 

 the liver, the formation of methaemoglobin, and anemia (La- 

 page, 1040; Habermann, Harwood and Hunt, 1941). Single 

 doses of 1,00(1 grams have produced fatalities in horses. Since 

 the toxic manifestations appear to be associated with the de- 

 struction of the erythrocytes, it is advisable to administer the 

 drug cautiously to horses suffering from anemia. The Bureau 

 of Animal Industry has issued a press release terming poor, 

 weak animals and those suffering from infectious anemia as 

 bad risks for treatment and it would appear that the drug 

 . should be employed with considerable caution in such cases. 



Hatcher (1941) reported the death of 5 of 12 horses, each 

 of which was given a dose of approximately 120 grams of 

 phenothiazine as an anthelmintic. Under experimental condi- 

 tions, doses of this size have caused no symptoms other than 

 discoloration of the mucous membranes, transient loss of ap- 

 petite and a temporary anemia. Grahame, Morgan and Sloane 

 (1940) administered 100 grams to each of 35 horses without 

 accident, and others have reported similar results. Possibly 

 under certain conditions horses may prove more sensitive to 

 phenothiazine than present experimental evidence suggests. As 

 a measure of precaution, wholesale treatment should be avoided. 

 The Bureau of Animal Industry recommends that when large 

 numbers of animals are to be treated with this drug, one or 

 two, the least valuable of the lot, be treated first to determine 

 tolerance for the drug. Such animals should be kept under 

 observation for a week before others are treated. If no bad 

 results are observed, the remaining animals should be treated a 

 few at a time and the observations repeated. This procedure 

 should be followed until the entire group has been treated. 



Phenothiazine may be administered to horses in gelatine cap- 

 sules or in a suitable suspension. In order to make a suspen- 

 sion of phenothiazine suitable for administration to animals, 

 it is necessary to use some chemical as a dispersing agent. 

 Numerous dispersing agents are known and many of these have 

 been employed ; however, few of these suspensions have been 

 given critical test. It is known that certain agents will greatly 

 reduce the efficacy of phenothiazine when such chemicals are 

 employed as suspending agents. Therefore, it is not advisable 

 to employ such mixtures unless they have been tested critically. 

 A formula which has been found satisfactory consists of 

 phenothiazine 50 grams (1.67 ounces), molasses 20 cc. (0.67 

 fluid ounces), and water to make 90 cc. (3 fluid ounces). The 

 molasses is thoroughly mixed with the phenothiazine, then a 

 small portion of water is added and thoroughly stirred in. 

 The process of alternately adding water in small quantities 

 and of stirring is repeated until a smooth suspension of the 

 required volume results. Also, phenothiazine may be mixed 

 with almost any ground feed. Since certain animals do not 

 take readily feed medicated with phenothiazine, the following 

 regimen may be employed : 



For one week prior to the administration of the drug the 

 horse should receive no salt. During this time it should re- 

 ceive daily one pint of a mixture containing equal parts of 

 oats and bran to which 50 grams (about 2 fluid ounces) of 

 molasses have been added. For administration of the drug, 

 .50 grams (1.67 ounces) of phenothiazine is incorporated in 

 about 150 grams (about 5 fluid ounces) of molasses, and this 

 mixture is mingled thoroughly with 2 quarts of an oats bran 

 mixture. Two ounces of salt are added to this formula. While 

 fasting is unnecessary, the medicated mixture should not be 

 placed before the horse until the animal is hungry. If the 

 horse hesitates to eat the medicated mixture, it may often be 

 encouraged to do so by sprinkling a small quantity of untreated 

 oats or corn over the surface of the mixture. Even if the drug 

 is administered in the feed, it is better to treat horses indi- 

 vidually rather than to attempt mass treatment. 



treatment for lungworm intection 



Skrjabin and Schul'ts (1936) and Kulikov and Tamarin 

 (1937) have advocated the use of iodine in a solution of po- 

 tassium iodide for the removal of lungworms from horses. The 

 material is injected intratraeheally while the horse is on its 

 back, slightly inclined to one side for the first half of the 

 injection, and to the other side for the remainder. The dose 

 is 250 to 300 cc. of a 0.1 percent solution of iodine in a 0.2 

 percent solution of potassium iodide. 



trb^tment for oxyuris equi infection 



Oil of turpentine is an effective treatment for the removal 

 of pinworms from the horse. Animals should be fasted for 



343 



