PARASITES AND PARASITIC DISEASES OF HORSES 51 
a practical field test for such dip. Of the various classes of dips used 
on horses, three only are on the approved list—arsenicals, lime-sul- 
phur, and nicotine. Of these the two most commonly used are the 
lime-sulphur dip for f 
mange and the ar- 
senical dip for lice 
and ticks. 
ARSENICAL DIP 
Arsenical dip, 
when properly used, 
eradicates biting and 
sucking lice, but it is 
not an effective rem- 
edy for mange. Pre- 
_pared arsenical dips 
have been placed on 
the market, but those 
which are permitted 
by the Government 
for use in dipping 
cattle for southern 
fever ticks are suit- 
able for use in dip- 
ping horses, mules, 
and asses for lice. 
The instructions on 
the label of the con- 
tainer should be fol- 
lowed in diluting and 
using ready-prepar- 
ed dips. The arseni- 
cal dip is not usually 
warmed or heated in 
the vat. 
It should be remem- 
bered that arsenical 
dip is a poison, and 
precaution should be 
taken to prevent in- E Asis tenets 8 se : | 
jury to man or ani- GURE 34.—Exit eee Sep ee pens of horse- 
mal. When it is 
handled and used with proper care it is a safe and effective remedy. 
Care should be taken not to get the clothing wet with the dip, and the 
hands should be washed frequently to prevent possible absorption of 
arsenic. 
Freshly treated animals should be held in the draining pens or 
other suitable place until all surplus dip has drained off. (Figs. 34 
and 35.) If allowed to drain where pools of dip collect from which 
the animals may drink, or if the pasture or feed becomes soiled with 
arsenical dip, losses are liable to occur. 
If homemade arsenical dip is preferred to the proprietary brands, 
see United States Department of Agriculture Farmers’ Bulletin 1057 
for full instructions for making it. 
