PREVENTIVE INOCULATION 71 
should be started early enough to allow the full course of 
injections to be completed a week or ten days before 
probable exposure, as in the case of dogs to be taken toa 
show. When used as a curative agent, the bacterin 
treatment should be started as early in the disease as 
possible, and it is strongly recommended that anti-dis- 
temper serum should be given in addition. Inno case 
should the appropriate medicinal, dietetic, and hygienic 
treatment be neglected. 
Directions for Use.—Either the liquid or a solution made 
by dissolving one or more of the tablets in sterile water 
is injected subcutaneously by means of a previously 
sterilised hypodermic syringe. Before withdrawing the 
bacterin from the vial, the surface of the rubber cap 
should be wiped over with a germicidal solution. It 
may prove easier to fill the syringe if the piston is with- 
drawn part way before puncturing the cap; if it is desired 
to withdraw rc.c., pull the plunger back slightly past the 
1 cc. mark. The air in the syringe should be forced 
gently into the vial, but not with so much pressure as to 
loosen the cap. By thus increasing the pressure in the 
bottle, it will be found that the syringe fills very readily, 
there being no partial vacuum to overcome. The punc- 
ture made by the needle is self-sealing, and if the instru- 
ment is sterile, the contents remaining in the vial will 
not be contaminated. 
Dosage.—One tablet containing 500 million killed or- 
ganisms is equivalent to o'5 c.c. of the liquid bacterin. 
For the initial prophylactic dose, 1,000 million organisms 
(1 c.c. of liquid) is considered safe for a 20-lb. dog. For 
smaller or larger dogs, the dose must be decreased or 
“bacterins.” Thus, Ferry’s preparation will be called one or the other 
according as whether we think in English or American terms. Being a 
suspension of dead organisms, it may well be alluded to as a bacterin 
for the sake of convenience or distinction, 
