432 Treatment of Canine Piroplasmosis 
Congo Red tested on 3 dogs by Nuttall (p. 415, this paper). All of 
the dogs died, but the drugs exerted a decided effect upon the 
parasites. 
4. Definite curative or preventive effects are exerted by: 
Trypanblue (C S4 H 24 N 0 O 14 S. 4 Na 4 , the tetrazo compound of toluidine 
and amidonaptholsulphonate of sodium) cured 7 out of 
9 dogs in the experiments by Nuttall and Hadwen (vi. 1909, 
p. 175) and when given early (ix. 1909, p. 229) prevented 
the appearance of the parasites in the dogs’ blood. These 
results have been confirmed by Jowett (x. 1909) who tested 
the dye on 14 dogs, two of which were moribund. The latter 
died whilst 12 recovered. Six of Jowett’s cases were due to 
experimental infection, the others were cases of naturally 
acquired infection, and a number showed severe clinical 
symptoms. The drug is ineffective when given by the mouth. 
(Nuttall and Hadwen, ix. 1909, pp. 231—233; confirmed by 
Jowett, x. 1909.) 
Trypanred tested on two dogs by Nuttall and Hadwen (vi. 1909) 
caused the parasites to degenerate and disappear. (Further 
experiments with this dye are in progress. The initial 
experiments indicated that trypanred is not as satisfactory as 
trypanblue for purposes of treatment as it produces a more 
irritant effect.) 
5. In dogs which have recovered from piroplasmosis after treatment 
with Trypanblue and Trypanred the blood remains infective and virulent 
for 6 to 7 months or more after treatment. Such dogs resist reinocula¬ 
tion with virulent blood obtained from dogs suffering from acute piro¬ 
plasmosis and, consequently, are to be regarded as “salted” animals. 
From a practical point of view the “salting” of dogs (and cattle) by the 
method of inoculation followed by the dye treatment appears to offer 
decided advantages. The method is at present on its trial in respect to 
cattle which are being “ salted ” in England prior to their exportation 
to Africa. 
6. In judging of the value of dyes in the treatment of piroplasmosis 
it is essential that accurate observations should be made with regard to 
their influence upon the parasites as well as upon the symptoms of the 
disease. Both in dogs and cattle the injection of trypanblue causes the 
pyriform parasites to disappear rapidly, the remaining parasites appear 
