a saline purgative immediately following the treatment. The 

 purpose of this is to prevent clumping of the ascarids, which 

 are inordinately stimulated by these compounds, and a possible 

 intestinal obstruction which sometimes causes enteritis, necro- 

 sis and death. Tetrachlorethylene may be given to cats at 

 the same dose rate and in the same manner as for dogs. The 

 drug in doses of 1 cc. has been reported to be of value for the 

 removal of ascarids from foxes. In these animals, it is said 

 to cause a slight enteritis which is not of serious consequence. 



Oil. of Chenopodium. Xumerous experiments have shown 

 that this drug is very effective for the removal of ascarids 

 from dogs. The rate of dosage is 0.1 ec. per kilogram of body 

 weight or 1.0 cc. for a 10 kilogram (22pound) dog. For prac- 

 tical purposes, this can be regarded as equivali'iit to th.' lol 

 lowing doses: For dogs weighing 10 pounds or 1 ss (except toy 

 dogs), 5 minims; for dogs weighing 10 to 20 pounds, 10 

 minims; for dogs weighing 20 to 30 pounds, 1.1 minims; and 

 for dogs weighing over 30 pounds, 20 minims. Toy dogs re- 

 quire small doses and considerable precaution should be ex- 

 ercised in treating such animals ; a dose of 2 or 3 minims is 

 advisable. The dog should be fasted from the afternoon of the 

 day previous to treatment and should be dosed the following 

 morning. The chenopodium should be accompanied by at least 

 an ounce (30 cc.) of castor oil. It is not advisable to give the 

 chenopodium in the castor oil. as chenopodium is salivating and 

 the combination produces a disagreeable slobbering effect. For 

 choice, the chenopodium should be given in gelatin capsules and 

 the castor oil administered immediately before or after the 

 capsules. The animal should not be fed until 3 hours after 

 treatment. If dogs show serious toxic effects, large additional 

 doses of castor oil should be given and enemas used to insure 

 prompt purgation. The contraindications for chenopodium have 

 been discussed in connection with the treatment of ascariasis 

 in man. 



Chenopodium is very effective for the removal of ascarids 

 from cats but the drug is more toxic for these animals than 

 it is for dogs. The dose for the cat should not exceed O.O.") ec. 

 l)er kilogram (2.2 pounds) of body weight, immediately pre- 

 ceded or followed by an adequate dose of castor oil. 



For fox pups, Young (1930) recommended 1-minim doses of 

 oil of chenopodium in castor oil and found this safe for pups 

 3 weeks old and effective for pups up to 8 weeks of age. He 

 preferred not to treat them until tlun- were 4 weeks old. 



Santonin. When there are contraindications for other treat- 

 ments, santonin in repeated doses may be used to remove as- 

 carids from dogs. Experiments show that single doses of 

 santonin, even very large doses, such as '2 grain for each 

 pound of body weight, are less effective than a single thera- 

 peutic dose of chenopodium, but that smaller doses of santonin 

 daily for several days gives very good results. Small dogs may 

 be given Vn grain of santonin and an equal amount of calomel, 

 and large dogs double this dose, daily for a week. Tliis should 

 be given early in the morning and the animal not fed for 2 or 

 3 hours. As previously stated, a saline purge following single 

 doses of santonin seoms to increase materially the efficacy of 

 the drug. 



N-BuTYL Chloride. The administration of tetrachlorethylene 

 to dogs is frequently followed by a temporary narcosis which 

 often embarrasses the veterinarian and alarms the client. Har- 

 wood, Jerstad, Underwood and Schaffer (1940) are of the 

 opinion that n-butyl chloride does not produce such reactions. 

 For the removal of ascarids, these investigators recommend the 

 following dosages: For dogs weighing 2.3 to 4..''i kilos (•") to 10 

 pounds), 2 cc; 4.."i to 9 kilos (10 to 20 pounds), 3 cc; 9 to 18 

 kilos (20 to 40 pounds), 4 cc; and 18 or more kilos (40 or 

 more pounds), 5 cc. 



Hextlresorcinol. Lamson, Brown and Ward (1930) have 

 reported that hexylresorcinold is very effective for the removal 

 of dog ascarids. The drug is given in doses of 0.5 to 1 gram. 

 With hexylresorcinol, it is necessary to withhold food for 12 

 to 18 hours before treatment. Animals should not be per- 

 mitted to crush or chew capsules or pills of hexylresorcinol 

 since, as previously stated, the drug is irritant to the mucosa 

 of the mouth. 



TRE.\TMENT FOR HOOKWORM INFECTION 



Tetrachlorethylene. At the present time, this is the drug 

 of choice having largely replaced carbon tetrachloride because 

 of the toxicity of the latter. The therapeutic dose rate of 

 tetrachlorethylene for dogs and cats is 0.2 cc per kilogram 

 (2.2 pounds) of body weight, or 2 cc. for a 10-kilogram or 22- 

 pound animal. It is usually not necessary to give a purgative 

 in connection with tetrachlorethylene, but a purgative is ad- 

 vantageous as it helps to sweep out worms killed by the treat- 

 ment and to eliminate the drug rapidly from the intestinal 



tract. It is advisable in coneomitant heavy ascarid infections, 

 particularly in puppies, to follow tetrachlorethylene with a 

 suitable dose of purgative. However, castor oil or other oils, or 

 fats, should not be given immediately preceding or following 

 tetrachlorethylene as they aid in tlie al)sorption of the drug. 

 Tetrachlorethylene has the disadvantage of causing in some 

 cases a transient vertigo or dizziness, which may be :ilarming to 

 the owner of the aninuil, hut which in fact is not serious and 

 which soon passes off. For this reason, as mentioned under the 

 section on the treatment of ascarid infection, n butyl chloride 

 may be used in place of tetrachlorethylene. The dosages sug- 

 gested for the removal of hookworms are the same as those 

 suggested for the removal of ascarids from dogs. 



Tetrachlorethylene can be used to advantage in the removal 

 of U ncinaria slenocrphala from foxes. The dosage is the same 

 as that for dogs. However, foxes do not tolerate anthelmintic 

 treatment as well as do dogs, and particular care should be 

 taken to judge accuratel.v the dosage of the drug and to ap- 

 praise closely the possible presence of contraindications for 

 treatment. Care should be taken to see that capsules are not 

 broken in the mouth, as inhalation of tetrachlorethylene may 

 lead to serious complications, particularly in fox pups. 



He.xylresorcinol. This drug can be used to advantage 

 when contraindications for other treatments are present. How- 

 ever, its efficacy falls below that of tetrachlorethylene and 

 many other halogenated hydrocarbons. The dosage is the same 

 as that given under treatments for the removal of ascarids. 



TREATMENT FOR TRICHURIS VULPIS INFECTION 



Numerous experiments on dogs indicate that a large number 

 of anthelmintics are potent in the removal of whipworms but 

 that a single dose of such drugs will rarely remove many 

 whipworms. The failure of single dose treatments is no doubt 

 due in part to the fact that the anthelmintic fails to enter the 

 cecum or enters it only in insufficient amounts. It is, therefore, 

 necessary to give a drug from day to day, until it does come 

 in contact with the worms in effective doses, or to give large 

 doses of relative^- non -toxic drugs to ensure the entry of the 

 drug into the cecum. 



Santonin. For the [uirposes of repeated treatments, san- 

 tonin is a very satisfactory drug since it does not cause gastro- 

 intestinal irritation even when given over a period of time. 

 The drug may be given to dogs in a dose of '4 to 1 grain 

 each of santonin and calomel, according to the size of the 

 animal, daily for 7 days. The treatment may then be dis- 

 continued and repeated after an interval of a week. 



Leche de Higueron. This drug has been described under 

 treatment for whipworms in man. While adequate tests have 

 not been carried out to estalilish its eflficac.v for the removal 

 of T. viilpix, it seems jirobable that it would be effective for 

 that purpose. However, until the material becomes more gen- 

 erally available, its use will l)e restricted to the geographical 

 areas in which the tree is indigenous. 



N Butyl Chioride. Harwood, Jerstad, Underwood and 

 Schaft'er (1640) showed n butyl chloride to be over .')0 percent 

 effective for the removal of whipworms. While this degree of 

 efficacy is certainly not satisfactory, these workers pointed out 

 that the drug is superior nevertheless to anj- other single dose 

 treatment known at present. As it is highl.v eft'ective for the 

 removal of ascarids and hookworms, it seems worthy of trial 

 in whipworm infections. For whipworms, the above-mentioned 

 investigators recommend a dose of 3 to o cc. for dogs weigh- 

 ing ."1 pounds or less; to 8 cc. for .j to 10-pound dogs; 10 to 

 12 cc. for 10 to 20-pound dogs; lo cc for 20 to 40-pound dogs; 

 and 2.J cc. for dogs weighing over 40 pounds. If the dog is 

 infected with ascarids, a saline purgative should be given im- 

 mediately following the anthelmintic* 



Other Methods. Hall and Shillinger (1926) found that 

 mercurochrome gave fairly satisfactory results for the removal 

 of whipworms from dogs when the drug was given in doses of 

 2 to 5 tablets each containing l.'i grains (96 mgm.) daily for 

 ') to 11 days. The drug removed 273 of 311 whipworms from 

 9 dogs, or 88 percent, and removed all whipworms from 4 of 

 6 infected animals. The safet.v of this treatment has not been 

 established. Although it has never come into general use, it 

 would seem worthy of trial. 



The use of drugs injected into the cecum by means of a 

 catheter passed per rectum has been advocated for the removal 

 of whipworms. However, it is extremely difficult to pass a 

 fiexable rubber tube in such a way that the operator has any 

 assurance that the orifice of the catheter is opjiosite the ori- 

 fice of the cecum and that the drug actually enters that organ. 

 In critical tests, Underwood, Wright and Bozicevich (1931), 



*Chitwood (personal communication) has obtained 100 percent effi- 

 cacy for whipworms when n. butyl chloride was administered in Ice 

 hard gelatin capsules at the rate of Ice per kilo body weight and with 

 no purgative. Purgatives appear to lower the efficacy of this drug. 



340 



