The action of arsenical dips in protecting cattle from infestation with ticks

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Material Information

Title:
The action of arsenical dips in protecting cattle from infestation with ticks
Series Title:
Bulletin / U.S. Department of Agriculture, Bureau of Animal Industry ;
Physical Description:
27 p. : ; 24 cm.
Language:
English
Creator:
Graybill, H. W ( Harry Webster ), 1875-1938
Publisher:
U.S. Dept. of Agriculture, Bureau of Animal Industry
Place of Publication:
Washington, D.C
Publication Date:

Subjects

Subjects / Keywords:
Cattle dip   ( lcsh )
Cattle tick -- Control   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by H.W. Graybill.
General Note:
"April 15, 1913."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029610060
oclc - 22255641
lccn - 13000433
Classification:
lcc - SF967.C38 G73 1913
System ID:
AA00018890:00001

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SCALE FROM INFESTATION WITH TICKS.
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WASHINGTON:

GOVERNMENT PRINTING OFFICE.

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BUREAU OF ANIMAL INDUSTRY.


Chief: A. D. MELvIN.
Assistant Chief: A. M. FABRINGTON.
Chief Clerk: CHARLES C. CARROLL.
AninGal Husbatndry Division: GEORGE M. RoMM"hief.
Biochemnic Division: M. DORSET, chief.-- (
Dairy Division: B. H. RAWL, chief. /
Field Inspection Division: R. A. RAMSAY, chief.
Meat Inspection Division: R. P. STEDDOM, chief. /
Pathological Division: JOHN R. MOHLER, chief. ( /
Quarantine Division: RICHARD W. HICKMAN, chdr'
Zoological Division: B. H. RANSOM, chief.
Experiment Station: E. C. SCHROEDER, superintendent
Editor: JAMES M. PICKENS.


ZOOLOGICAL DIVISION.
Chief: B. H. RANSOM.
Assistant Zoologists: ALBERT HASSALL, HARIY W. GRAYBILL, MAURICE C. HALL,
and HOWARD CRAWLEY.
Junior Zoologist: WINTHROP D. FOSTER.
2


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LETER OF TRANSMITTAL.


I... IT!)D STATES DEPARTMENT OP AGRICULTur- ,
h" BURtEAU OF ANIMAL INDUSTRY,
.... .- Washington, D. C., January 23, 1913.
30 I have the honor to transmit for publication as a bulletin of
$!bw" au the accompanying manuscript entitled "The Action of

lmsical Dips in Protecting Cattle from Infestation with Ticks," by
S W. Graybi, of the Zoological Division of this bureau.
Grto1he work.herein described was undertaken mainly for the purpose

1,-mermining to what extent and how long an arsenical dip protects
S ,, A from ifestaAti -ith .ticks after dipping. Three experiments
Pi ;ldueted wi 1Al ;tby which it was found that infestation
dfor t* days, and that there was no protection when
zpos*, ure to infestation occurred five days or longer after dipping.
\er experiments to ascertain if the protection extends beyond
.I ts.ys ar in progress and will be reported later.
i p. sent work includes a series of experiments made with cattle
kb.. to determine the manner in which substances used in dips (oils
d arsenic) act upon them. It is shown that ticks are destroyed by
is either by suffocation or by poisoning, or by both.
S Respectfully,


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ilHon JAnES WILSoN",
Secretary of Agriculture.





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A. D. MNLVIN,
Chief of Bureau.





















CONTENTS.

Page.
Summary ....................................... ......... ............ ...... 5
Introduction ............................................................. 6
Composition of arsenical dips ............................................... 8
The manner in which dips act on ticks ..................................... 9
The action of oils and other substances on ticks........................... 9
Smearing the spiracles- ........................................... 9
Smearing the scutum and mouth parts ............................... 12
Dipping the ticks in oils ............................................ 13
The effect of arsenic on ticks ........................................... 15
Cattle-dipping experiments to ascertain the protective action of arsenical dips. 16
Experiment No. 1.-Cattle exposed to infestation at various intervals from
a few hours to four weeks after dipping ............................... 16
Observations on engorged ticks removed from the animals ........... 17
Discussion of results................................................ 19
Experiment No. 2.-Cattle exposed to infestation 2j hours and two days
after dipping....................................... ................. 23
Discussion of results ......-........................................ 24
Death of animals from arsenical poisoning ........................... 25
Staining of tissues of animals treated with trypan blue ............... 26
Experiment No. 3.-Cattle exposed to infestation five days after dipping. 26
Discussion of results.................................................... 27
The method by which animals are protected against tick infestation........... 27
4













ACTION OF ARSENICAL DIPS IN PROTECTING CATTLE FROM
i -: IFETATION WITH TICKS.
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H H: :SUMMARY.
"bogle.t the factors entering Into the efficacy of dips used against ticks
SDips act both in a direct destructive way and in a protective
",:BK1preventing- infestation. The protective action of a dip may be in the
g a destructive or of a repellent action. The influence of dips on ovi-
and the viability of the -eggs is a factor in efficacy.
..hIneients of homemade arsenical dips and the known or probable
of each Ingredient are discussed.
isVu d -U herein that any protective acttbn that the usual arsenical dips
...e would be expected to be due to a toxic rather than to a repellent
...| alc, iitcbord has-shown that cattle dipped in arsenic are poisonous

!a-e destroyed by dips either by suffocation or by poisoning, or by both
....tests'e"were conducted showing that ticks are suffocated by the closing.
y pratory openings.. spiracless). It was found that practically all en-
ema:les that had :.their spiracles closed with Canada balsam died. In
tEstt of the same sort, in which oils were used, Beaumont oil proved much
ieetive than Canada 'balsam, and cottonseed oil was practically -without

J..t1i the situm and mouth parts of engorged females with oils and vis-
i tancs had no'i.fluence on the mortality, or oviposition, or on the per
ril:i^i ,sb egg hatching.
:sA .. tests in which engorged females were dipped in Beaumont oil and in
hii,. k W ..
9ItII toeed oil the former proved very much more effective than the latter, and
tIII1 ,ii due in all probability to a toxic action. Beaumont oil had a marked
Ihtience l.on0 vl Oibsltion, on the number of eggs deposited, and on the viability of
1i. i. wh.ereas cottonseed oil had no effect.
':... "....^ i. possiblee avenues for the entrance of arsenic into the bodies of ticks are
.. we..., rated, and the porose areas are pointed out as possible vulnerable points
:!." .. ...".
I a;.,.. |te armor of the tick.
^:'H i'Three cattle-dipping experiments were conducted with an arsenical dip con-
: ta1hing 8 pounds of arsenic trioxid to 500 gallons of water, in order to test its
Pti: eetlve action against tick infestation. Seed ticks were placed on the cattle
.at trying p..eriods after they were dipped. In the first experiment the ticks
.,.'w. placed on the cattle at periods ranging from a few hours to four weeks,
$,b^" second from a few hours to two days, and in the third at five days after
"pplg.i It was fobun that the dip rendered no protection when the exposure to
''"it:: dO wds fivb days or- longer after dipping. The limit of protection
UIbertsbzu* .h the experiments was two days. No tests were made covering
Hi... t1ntetiW0 g period between two and five days.
1!,[::T:.i.--A.:Ars pMg w which occurred among the animals in one experiment
appar by undisolved arsenic in the dip. It would therefore
s Mnthat imd lsolvednm arsenic in a dip is highly dangerous.
5
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ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.


It is shown conclusively that the protective action of arsenic is dependent on
its toxic action, and not on a repellent action.
As a result of incidental observations made on engorged female ticks from
animals suffering from Texas fever it was found that the mortality of such
ticks may be very high, as much as 95 per cent. The cause for this is not
known. It may be nutritional in character, due to the changed or impoverished
condition of the blood absorbed, or it may be due to the parasitism of Piro-
plasma bigeminum, the microorganism which is the direct cause of Texas fever.
Observations made for the purpose of determining whether there was any
relationship between the degree of infestation and the time elapsing between the
last dipping and the infestation, and also on the mortality of engorged females
from dipped animals infested subsequently to dipping, as compared with that of
ticks from undipped animals, were inconclusive. Oviposition and viability of
the eggs of these ticks appeared to be unaffected.

INTRODUCTION.
The efficacy of a dip used against such a pest as the cattle tick may
be considered under two heads, namely, its direct destructive action,
and its protective action in preventing reinfestation. (Protective
action may be the result either of a destructive or of a repellent action,
or of both.) These properties are no doubt combined to a certain
degree in all dips that have proved effective against ticks. The rela-
tive importance that they assume, from a practical standpoint, de-
pends on the particular purpose for which dipping is done. If it is
desired to render cattle free of ticks, and they are not to be subjected
to the dangers of reinfestation, the protective value of the dip is of
minor importance. On the other hand, if the purpose is to eradicate
the ticks from a- given area, and the animals are turned back on in-
fested fields subsequent to each treatment, the protective value of a
dip assumes considerable importance. In the former case the pro-
tective properties would be of value only in case the animals should
by accident be subjected to infestation subsequent to dipping, whereas
in the latter case they would play an important part in bringing
about extermination. It is conceivable, though we have no such dips
at present, that a dip might stand low in its direct destructive action
and still prove highly effective in eradication work because of its
protective (repellent) properties.
In addition to the destructive and protective qualities of a dip
another factor must be considered, and that is its influence on ovipo-
sition and on the viability of the eggs deposited. It has been pointed
out in Bulletin 144 of the Bureau of Animal Industry that arsenic
diminishes both the number of eggs deposited by females that survive
and to a marked degree the viability of the eggs. Certain oils also
affect the number of eggs deposited and the viability of the eggs.
Various oils are known to be more or less effective against ticks, and
they all no doubt possess a certain amount of protective value, de-
pendent on their odor, their disagreeable nature, or the destructive

















... sparamn: w maKe wuu ganons o01 aip) were aeaa a mne ena
days, and that in the case of horses 22.5 per cent of the.ticks
4ed. In one experiment in which horses had been frequently
t.e tick mortality was 36.8 per cent among ticks that attached
Ite course of three days.
&I dips containing sodium metarsenite in alkaline solution
Fve.. o a i of .pine tar could not be expected to exert any
on because of their physical nature or their odor, except
~I 4t: aas te tIqr is concerned, the action of which, however, must
.. .....TW ight. Any protective value that such dips have, therefore,
iy depend largely on the toxicity of the arsenic present
t..he skin of dipped animals. Watkins-Pitchford2 found
S arsenical dip above mentioned retarded infestation with
:tisAnd nympJs of the brown tick. The time between treatment
p4n|femttioun Jai not stated, but it was presumably only a few hours.
i 9i0 ra..ttributed the protective action to the paraffin component
4! $h ii p. It was found that dipping did not hinder infestation
a idult of the brown tick, but that the number on cattle sub-
-1jpcted to infestation rapidly decreased as a result of the poisonous
;fq .ct.. f hearsenic present in the skin of the animals.
11^, th.e work of tick suppression and tick eradication in this and
....r ioun^*trieis arsenical dips have proved satisfactory when used
%. .. regular intervals. The strength of the dip and the interval be-
eien.. reatments have been determined with a view of obtaining the
st .results with as little injury to the cattle as possible. The inter-
)i1 b~e~t~ween dippings has rested largely on an empirical basis, except
in| thii, cahsCe of t-atment directed against certain species of sticks of
omp m.;:: :iim.portance in South Africa that drop from their host
W. wusto"~~~..hmolt, in ..which case the period has been based in
^^^on the minimum time the tick has been found to re-
S.:.l.edtol the host. Little is known as to how much the ar-
a.a.. ...tr ni Journal, Pletermsrltburg, vol.: 15, no. 3, Sept., 1910, pp. 312-328.
Ag.uflta .obnal.Union of South Africa, Pretoria, vol. 2. no. 1. July, 1911, pp.
% Rnodl..b a.- Agricultural Journal, Salisbury, vol. 10, no. 3, Feb., 1912, pp. 372-400.
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ACTION O ASENIAL DIPS AGAINST CATTLE TIC .

senical dip plays in a protective way in bringing about the results
that have been attained. It was with a view of determining to what
extent and for how long arsenic protects against infestation that the
experiments detailed in this paper were taken up.
COMPOSITION OF ARSENICAL DIPS.
Arsenic seems to have almost a specific action on ticks. The
arsenical dips in use against ticks as a rule have their arsenic present
in the form of sodium or potassium metarsenite, the former of which,
however, in the presence of bacterial growth, as shown by Fuller,1
gradually becomes oxidized to the arsenate. In the home-made
dips used in this country the only other ingredients are an excess
of" sodium carbonate and pine tar. In formulas that were for-
merly tried in this country, and some now in use in other countries,
there are other ingredients, such as soap and emulsified paraffin
(kerosene).
Watkins-Pitchford 2 has found that paraffin emulsified with soap
in the dip ameliorates its irritative action and that the addition of
emulsified paraffin and glycerin subdues this action still more. It
is not likely that the soap, pine tar, or paraffin exert any important
destructive action on ticks, especially in view of the fact that they
constitute less than 1 per cent of the dip. Watkins-Pitchford 3 found
that the mortality of ticks in the case of two arsenical dips was
raised 1.8 and 5.7 per cent by the addition of soap and paraffin. His
observations, however, were based on too small a number of ticks to
be considered conclusive. All three of the ingredients mentioned
may serve a certain function in causing the arsenic to adhere more
tenaciously to the skin and hair, and the tar and paraffin may
exert a slight amount of repellent action because of their odor and
physical properties. They also serve the purpose of giving the dip a
distinctive character. The soap serves a function in the emulsifica-
tion of the tar or kerosene, depending on which is used, and probably
exerts a certain amount of cleansing effect on the skin.
The excess of sodium carbonate in the two formulas in use in this
country, in which 8 and 10 pounds of white arsenic are used to 24
and 25 pounds, respectively, of sodium carbonate, is considerable.
Whereas only 1.45 parts by weight of sodium carbonate to 1 part of
arsenic are necessary in the formation of sodium metarsenite, in the
above formulas 21 to 3 parts are used to each part of arsenic. How-
ever, this excess of sodium carbonate serves a number of important
purposes. It facilitates the solution of the arsenic, aids in the emul-
'Circular 182, Bureau Animal Industry, U. S. Department of Agriculture. Washington,
1911.
Natal Agricultural Journal, Pietermaritzburg, vol. 12, no. 4, Apr. 30, 1909.
3 Agricultural Journal, Union of South Africa, Pretoria, vol. 2, no. 1, July, 1911, pp. 33-:
79. Rhodesia Agricultural Journal, Salisbury, vol. 10, no. 3, Feb., 1912, pp. 372-400.













poisonea, or Dy a comomanon or Dorn causes. in mte case
......... of such substances as oils it is probable that death is due
Uits tbaion and to a toxic action.
.O.h IyfACTION OF OILS AND OTHER SUBSTANCES ON TICKS.
SMEARING THE SPIRACLES.
i ticks may be suffocated the writer has shown by closing the
hof engorged females of the cattle tick with Canada balsam.
May 19., 1911, 10 engorged females that had already begun to
0 i Jtd their spiracles closed with a drop of balsam. On the
EiMi win day' the ticks were normal in color but were inactive, their
s"trc.ed out straight. On the third day all the ticks had
W" drk and: were dead. No eggs were deposited. In the con-
; loof- 10 ticks 4 died. Many eggs were deposited, 40 per cent
.... *wbio:"i~h hatched.
^i^ order to determine whether the xylol in the balsam may not
l|!1itWil&.played patM in the destruction of the ticks a second test was
m|... y 26 In which the spiracles of 10 engorged females that
begun to oviposit were touched with xylol. One tick turned
S ....All oviposited, and a normal number of eggs were deposited,
IIoI t30 .per cent of which hatched.
:l ';Oa- SeptLember 27, 1912, another lot of 20 engorged females just
fix:: elected had their spiracles touched with Canada balsam. On Sep-
tei ber 30 all of them were dead. In two control lots of 20 engorged
SmslesT a each, collected on the same date, all the ticks remained normal
Ia nd oviposited; 92 and 60 per cent of the eggs hatched.
.i uSept ember 29, 1912, a third lot of 20 engorged females, col-
Iq.. ted 0o September 27,1912, had their spiracles touched with Canada
H :.a.in: Seventeen of the ticks were killed, the remainder deposited
I m. n' al eggs. Eighty-seven per cent of the eggs hatched. In two
S a tMlots of 20 ticks each, collected on the same date as the above
i lo,:0ll oviposited and a usual number of normal eggs were deposited;
W S d 80 per cent of the eggs hatched.
Fr omjhe above tests it may be definitely concluded that a eom-
r- po. olin g of the spiracles of engorged females will lead to their
.detruction. In the case of the three ticks in the last lot that sur-
... .. ....
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4i.::o.4it seems .safe to assume, in view of the number of positive tests,
ti.thlie spiracles were not completely closed.
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hi
10 ACTION OF ARSENIOAL DIPS AGAINST CATTLE TICKS.
Some additional tests were made along the above line with other
oils. On May 13, 1911, eight engorged females that had already
begun to oviposit had their spiracles smeared with Beaumont crude
petroleum. All but one continued oviposition. Three of the ticks
died. Many eggs were deposited, 25 per cent of which hatched. In
a control lot of seven ticks all continued oviposition. Four ticks
died. A fair number of eggs were deposited, about 30 per cent of j
which hatched.
September 27, 1912, 20 engorged females collected on that date
had their spiracles touched with crude Beaumont oil. One (5 per
cent) of the ticks died. It had apparently been injured about the
head when removed from the host. Three ticks remained plump.
Nineteen ticks oviposited, and a normal number of eggs were pro-
duced. Seven per cent of the eggs hatched.
September 27, 1912, 20 engorged females just collected had their
spiracles touched with refined cottonseed oil. None died. All ovi-
posited, and a normal number of eggs were deposited. Ninety-two
per cent of the eggs hatched.
Two control lots of 20 ticks each, collected on the same date as the
above, remained normal. All the ticks oviposited, and a normal
number of eggs were produced; 92 and 60 per cent of the eggs
hatched.
On September 27, 1912, 20 engorged females just collected had their
spiracles touched with Beaumont oil. One (5 per cent) failed to
oviposit. Three (15 per cent) died. A normal number of eggs were
deposited. Twenty per cent of the eggs hatched.
On September 28, 1912, 20 ticks collected on September 27 had
their spiracles touched with refined cottonseed oil. None of the ticks
died. All the ticks oviposited, and a normal number of eggs were
deposited. Ninety per cent of the eggs hatched.
In two control lots of 20 ticks each, collected on the same date as
the above, none died, and all oviposited, a normal number of eggs
being produced; 80 and 92 per cent of the eggs hatched.
On May 26, 1911, 10 engorged females that had begun to oviposit
had their spiracles touched with pine tar. All oviposited, and a
normal number of eggs were deposited, 15 per cent of which hatched.
In the control lot of 10 ticks, all but one oviposited, and five died
without completing oviposition. Many eggs were deposited, 10 per
cent of which hatched.









... ....... T icks
...%i:. .. .::. .: : :: ... .... I y .N m b o f
t.t. o. "" cvpW. NqmT W. f Substance used.
iil .."p .. ... .l"u g..""d.. a p .:i.e" d". 7 ':'y ..

V N--, iv -i ...P. Per ent.
i 8Man........ 25 Beaumont oil.
*7 100 Fa ........... g3 (Control.)
*' | ''' '"": 4 0... 100 .4n0.... ..UDo
S9....**. ... 5 Normal....... 7 Beaumont oiL
I ..... ............ 0 100 .....do........ 92 Cottonseed oiL
.-": -;.... .... 0 100 .....do........ 92 (Control.)
-w: l ....:.'... "...... ........ 0 100 .....do........ 60 Do.
.........'*^ '^- "-----** 15 9 ..... do ........ 20 Beaumont oil.
............. 100 ... ..do ......u.
...."* 0 10 ..-..do........ 90 Cottonseed oil.
.."........ ......... ..........5. 0 100 .. ...do.... 80 (Control.)
............. ........... 0 100 ..... do......... 92 Do.
:,I.. ........ ..... ......... .. ....... 100 ....do....... 15 Pingetar.
..,1 -:,-... '...... ... ... ..... ......50 go90 AM y......... 10 (Control.)

Ai ; nte from the above table that the mortality of the different
i*E oicks treated with Beaumont oil compared with that of the
.0" M. findng g control is iS as follows: 38 per cent, control 57 per cent;
controlss 0 per cent; 15 per cent, control 0 per cent. This
a dtimental effect of the Beaumont oil, but is in marked
tAbt withte results obtained when the spiracles were closed with
ibalsvm, in which ease the mortality was practically 100 per
The| mortality in the case of cottonseed oil was 0. Beaumont
Infore, appears to be much more effective thai cottonseed oil
|', 6 loing the spiracles, although it should be borne in mind that
.. ..ay .be a tiAic effect that entered into the results. It is evident
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EI Beumont oil does not close the spiracles as effectually as Canada

B|' e picentage of ticks in the lots treated with Beaumont oil that
|IA: "ipa1sited, comparedd with the percentage in the corresponding con-
Mri is as fellows: 88 per cent, control 100 per cent; 95 per cent,
-e ntrols 100 per cent; 95 per cent, controls 100 per cent. It appears
. .. r . this that the treatment had a slight effect on oviposition. Cot-
1iOK ei' i ed oil had no effect on the percentage ovipositing. The treat-
I* ,iiemt in no case had any effect on the number of eggs deposited. The
*:z Dercentage of eggs that hatched in the case of the ticks treated with
Z Ieamnont oil, compared with the percentage in the corresponding
I:s ;bntrol lots, is as follows: 25 per cent, control 30 per cent; 7 per cent,
"cli.. tr.lp 60 and 92 per cent; and 20 per dent, controls 80 and 92 per
". .From this it appears that the Beaumont oil applied to the
| %ita clra t have been absorbed to some extent and by this means
..I.... e.rted a detrimental influence on the eggs.
I" ,The percentage of eggs hatching in the case of ticks treated with
,. coto e oil, compared with that of the corresponding controls, is
as.. allowss:,. 92 per cent, controls 60 and 92 per cent; and 90 per cent,
|:; eoflols ,to 92 per cent. It is therefore noted that cottonseed oil
.... ..-. no influene on the eggs.
N, '

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12


ACTION OF ABRENICAL DIPS AGAINST CATTLE TICKS.


SMEARING THE SCUTUM AND MOUTH PARTS.


In order to determine whether the presence of an oil or viscous
substance on the scutum and mouth parts would interfere with ovipo-
sition and the laying of normal eggs, a number of tests were made.
On June 8, 1911, 10 engorged females that had already begun to
oviposit were smeared on the scutum and mouth parts with Beaumont
oil. Eight of the ticks died. All but one of the ticks deposited
some eggs. Only a few eggs were deposited, none of which hatched.
In the control lot of 10 ticks, 6 died. All oviposited. A moderate
number of eggs were deposited, none of which hatched.
On June 8, 1911, 10 engorged ticks that had begun to oviposit were
similarly smeared with Canada balsam. All but one oviposited.
Eight ticks died. A moderate number of eggs were deposited, less
than 1 per cent of which hatched. In the control lot of ticks, six died.
All oviposited. A moderate number of eggs were deposited, none
of which hatched.
On June 8, 1911, 10 engorged females that had begun to oviposit
were smeared on the scutum and mouth parts with pine tar. All
the ticks oviposited. Eight died. A considerable number of eggs
were deposited, 10 per cent of which hatched. In the control lot, con-
sisting of 10 ticks, 6 died. All oviposited. A moderate number of
eggs were deposited, none of which hatched.
September 27, 1912, 20 engorged females just collected were simi-
larly smeared with crude Beaumont oil. All oviposited. A normal
number of eggs were deposited. Fifty per cent of the eggs hatched.
On September 27, 1912, 20 engorged females just collected were
smeared on the scutum and mouth parts with refined cottonseed oil.
One tick became discolored. Two more ticks became discolored
shortly before oviposition was completed. All oviposited. A normal
number of eggs were deposited, and 87 per cent of the eggs hatched.
On September 27, 1912, 20 engorged females just collected were
similarly smeared with Canada balsam. All oviposited. A usual
number of normal eggs were deposited. Seventy-five per cent of
the eggs hatched.
In two control lots of 20 ticks each, collected on the same date as
the above, none died. All oviposited* A normal number of eggs
were deposited; 92 and 60 per cent of the eggs hatched.
On September 27, 1912, the scutum and mouth parts of 20 engorged
females just collected were smeared with crude Beaumont oil. One
tick (5 per cent) died and one became abnormal in appearance. All
but one oviposited. A normal number of eggs were deposited.
Eighty-five per cent of the eggs hatched.
On September 28, 1912, the scutum and mouth parts of 20 engorged
females collected on the previous day were smeared with refined


,. *;








':i
1
,:
.*
"i
."
:









i saem1's ,u e- of eggs were deposited. N inetyaidve per

ber:291 1912, the scutum and mouth parts of 20 engorged
ci:: e d: September 27 were smeared with Canada bal-
'1N :Jtt tiCks lived and oviposited. A usual number of normal
deSPosited. Fifty per cent of the eggs hatched.
oewitrol lots of 20 ticks each, collected on the same date as
none died. All oviposited and a normal number of eggs
I poted ; 92 and 80 per cent of the eggs hatched.

of. tets in which the scutum and mouth parts of engorged females
were smseared with oils.
77Hi
lE|!j '+.... Mortal- Ticks ovi- Number:of eggs Eggs
ti6f test. I 4+. Tlnjd1ISubstance used.
..i: ... .ty.1 positing deposited. hatched.
-..A..... U:h,.. .. .... .... .. U ,=
ii ..". .. i:.:. : :. ":...
..l... . Per cest. Percent. Percent.
iBi: - ......- ...- ..80 1 90 A few................ 0 Beaumont oil.
l i*; 0it... ... ....... 6 1I00 Moderate.............. 0 (Control.)
8 g .anada bsam.
0.................... 80 90 -..... --........ ()
i!E . ..60 10)0 .....do .............. d-0 (Control.)
H 80 100 Considerable 10 tue tar.
jIP J'$M*ar^~ 60 100 Moderate............-.*0 (Control.)
Ali;!: i!! : W.-A....: ...... ....... D0 : 100 M d r t . . .


7. .... 100 Normal............. 50 Beaumont oil.
,::.. ..... .................... 1 0 0 do. ............. 87 (Cottonseed ol .
':,, ... ; ............. 0 100 .....do..............75 Canada balsam.
S. ..........do...............92 (Control)
.,..............."0 100 .. do .............. 60 Do.
... ....= .... .. .. . .. . ................

... ..............5 95. -do..............5 85 Beaumont oil.
.. ::........:i2"..... s'"80 .....do.............. 95 Cottonseed oil.
.......:.:-. ............ ....... *0 '100 .....do .............. 50 Canada balsam.
i |:.&.1... ....... ..... 100 do.............. 92 (Control.)
ryl a .............~~ 1 .......... .do ............... 80 Do.
''"" ...... .. .. Less than per cent.o
..""' "r .* .. 'Three (15 per cent) became discolored.
One more (5 per cent) became abnormal in appearance.

II li the tfsts in the above table, started on June 8, 1911, the high
mortalit ;o',f' the ticks was no doubt due to the fact that they had
t' :..:. . ..... .. . itSyn ~ c n ,-


be -sent in., fro the South and in consequence had been injured to
|| a certain extent. A comparison of the mortality of the treated ticks
S"sith that of the correspontding controls indicates that the treatment
b| p4syed nO important part, if any, in determining the percentage of
; orMtality. It is likewise apparent that the treatment had practically
I itllfinence on the number ovipositing and on the number of eggs
depoeited, and, so far as can be determined, the same seems to be
y -, W ti ri'trm egard t6 the viability of the eggs.

Ak.i)4r Dt* flIPPING THE TICKS IN OILS.
r,. Atn e of tests were made in which ticks were dipped in crude
, *",,utont oil and in refinedbott onseed oil.'
Ohim t* Spteb.r 27, 1912, 20 hntgoged females just collected were
S Elen (12?) oviposited. Eight
:::iiii .'d*- e Bneanumbe wontin OIL Elv n the21 numbier. oEight-





14 ACTION OF AREICAL DIPS AWANST CATTLE TICKS. 4'.

(40 per cent) died. Only a small number of eggs were deposit
part of which shriveled. Less than 1 per cent of the eggs hatched. .....
On September 27, 1912, 20 engorged females just collected were -
dipped in refined cottonseed oil. One tick (5 per cent) died. All |
oviposited. A normal number of eggs were deposited. Ninety per '
cent of the eggs hatched. *
In two control lots collected on September 27, consisting. of O20
ticks each, none died. All oviposited and a normal number of eggs
were deposited; 92 and 60 per cent of the eggs hatched.
September 27, 1912, 20 engorged females just collected were dipped "
in Beaumont crude petroleum. Thirteen ticks (65 per cent) ovi- 4
posited. Eight ticks (40 per cent) died. Several others became
abnormal in appearance. Only a few eggs were deposited, about
half of which shriveled. Less than 1 per cent of the eggs hatched.
September 28, 1912, 20 engorged females collected the previous day
were dipped in refined cottonseed oil. All but one tick remained
normal. A normal number of eggs were deposited, some of which
shriveled. Eighty-five per cent of the eggs hatched.
In two control lots of 20 ticks each, collected on September 27,
1912, all oviposited. A normal number of eggs were deposited; 92
and 80 per cent of the eggs hatched.

Summary of tests in which engorged ticks were dipped in oils.
Date of tst. Mor- Ticks ovi- Number of eggs Eggs o used.
Date of testality. positing. deposited, hatched.

Per cent. Per cent. Per cent.
September 27, 1912 ............. 40 55 Small ...--............ (1) Beaumont oil.
Do ....................... 5 100 Normal ............. 90 Cottonseed oil.
Do ........................ 0 100 .....do .............. 92 (Control.)
Do .........- .............. 0 100 ..... do .............. 60 Do.
Do ........................ 240 65 Few................ (1) Beaumont oil.
September 28, 1912 ............ 30 .......... Normal ............. 85 Cottonseed oil.
September 27, 1912 ............ 0 100 .....do .............. 92 (Control.)
Do....................... 0 100 .....do .............. 80 Do.
I Less than 1 per cent.
2 Others became abnormal in appearance.
3 One tick (5 per cent) became abnormal in appearance.

In the foregoing table it is noted that the mortality in the case of
ticks dipped in Beaumont oil was 40 per cent in both tests, and in the
case of ticks dipped in cottonseed oil it was 5 per cent and 0 per cent.
Beaumont oil is therefore shown to have a greater destructive action
than cottonseed oil, and this is probably due largely to a toxic action
of some kind, since in the tests in which the spiracles were touched
with Beaumont oil this oil was shown to be much less effective than
in the present tests. Beaumont oil reduced the percentage of females
ovipositing and the number of eggs deposited. Cottonseed oil had
no influence on oviposition or on the number of eggs deposited. The
percentage of eggs hatching in the case of the ticks dipped in Beau-




















iriu of Animal industry, the possible ways are (1) through the
( 2) through the breathing pores; (3) through other opeb-
jjj the -body; or (4) by absorption through the cuticle. Arsenic
.. ... .. g by way of the mouth may enter in two ways, namely,
S o. ..r indirectly through the blood or lymph. Under other
fthebody may be mentioned the anus, the genital pore in
Si:i.::tieks, "the cephalic gland in the female and nymph, and glan-
Wo Ingrs. in the cuticle.
KKA.I sft"not likely that any dip enters the body through the anus or
v#a openings, as these are kept tightly closed. The cephalic
Sl."ie".e lcate4 beneath the scutum and having its opening situated
4L, O soft chitin between the scutum and the base of the rostrum,
I&:::,, possible point of entrance. This gland secretes a viscous
i44 which causes the eggs to adhere together and protects them from
lo . of moisture by evaporation. Anything that would interfere
i;th the function of this gland would affect materially the viability
K 1 of4Ae egg deposited. The openings of the tegumentary glands,
Wi c i h are numerous, furnish another means of entrance of arsenic
An [,!l .,, .. ...... .. ...
tIIo: ..gh the chitinous covering of the body.
TIK"he porose areas, two in number, located on the dorsal side of the
II base of the rostrum, furnish another possible point of entrance in the
|, case of adult females. According to Bonnet1 the punctations of
iP ese areas are pores passing through the chitin, each of which com-
I ,,univates with an exposed nerve cell lying beneath the chitinous coy-
..gi!?, V and which is the termination of one of the fibers of a nerve
4ill aceat to the area. As these nerve cells are without cell membranes
K.: 44uprtc ted in any way, it would appear that the porose
II: areas constitute a most vulnerable point in the body of the tick for
tfe entrance of arsenic.
at:. ti.". Aa..e1e. kweherchesm ur 'aatomle compare et le dTveloppement des
^*Kfji4h 4flj~e~Us de l'UniversitE 4e Lyon, m6 m, I: -.m m6d, fuae. 20. Lyon and Paris.

"'1W"
i% i .... .. .. .. ... ... ..... .
........ i~l. ..... i i ii ; ..... .. . . ... .... ...





16 ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.

CATTLE-DIPPING EXPERIMENTS TO ASCERTAIN THE PROTECTIVE
ACTION OF ARSENICAL DIPS.
I
EXPERIMENT NO. 1.--CATTLE EXPOSED TO INFESTATION AT VARIOUS INTER-
VALS FROM A FEW HOURS TO FOUR WEEKS AFTER DIPPING.
In this experiment the arsenical dip used was made on April 9,1912.
No pine tar was used, for the purpose of avoiding any repellent
action that it might contribute to the dip. The dip was made in the
usual way, the formula being 8 pounds arsenic trioxid and 24 pounds
of sodium carbonate to 500 gallons of dip. Samples of the dip were
taken on three dates for analysis. The analyses 1 follow:
Analyses of arsenical dip used in experiment No. 1.
Date. Actual Total
Asegs. AseO,.

1912. Per ce at. Per cent.
A r. 29 ....................................................................... . .. 0.1847 0.1851
ay 16 .............................................................................. .1841 .1901
June20............................................................................. 1229 .2022

It is seen that at the time of the first dipping there was present
in the bath 0.1847 per cent of As203 and a total amount of arsenic
equivalent to 0.1851 per cent of arsenic trioxid, and on June 20, two
days after the last dipping, 0.1229 per cent of As203 and a total
amount equivalent to 0.2022 per cent arsenic trioxid. The actual
amount of As2O3 present had decreased during the course of the dip-
ping about one-third through oxidation, and the percentage of total
arsenic had increased slightly as a result of evaporation.
Each animal was kept in the dip two minutes.
There were 12 animals (calves) in the experiment, all being north-
ern cattle nonimmunee). Each animal was infested with the seed
ticks hatched from 2j grams of eggs. The seed ticks used were the
progeny of engorged females (Margaropus annulatus) collected at
Fort Worth, Tex.. May 3, 1912.
Previous to the time the calves were infested they were kept irn a
yard provided with shelter, which they might seek when they desired.
On the day of infestation (June 18) they were removed to another
yard where there was no shelter and kept there until the following
noon, when they were placed under cover, where they remained unti!
the lose of the experiment. During the night and the forenoon fol-
lowing infestation the animals were out in a light rain.
Lot 1. Calves Nos. 942 and 947.-June 18, 1912, the calves were dipped once in
an arsenical dip containing a total amount of arsenic equivalent to 0.2022 per
cent As20, and containing arsenic in the form of ASO3 to the extent of 0.1229
7 All analyses referred to in this bulletin were made by the Blochemic Division of the
Bureau of Animal Industry.


































y(and 21), at intervals of two weeks, inical dip. Four weeks
the last dipping (June 18) they were infested with seed ticks. Calf 943
.:... ....heavily infested with ticks and calf 945 acquired a moderate infestation.
.. .rac....... ed. Texas fever, and calf 945 died July 8. The stages present were
:..:: i--and young adults. In the case of calf 948 the last tick was collected
: August 3, and in all 5,715 ticks were removed.
J: ...tn (control). Calves Nos. 4,6 and 950.-These animals were not dipped.
T' were infested with seed ticks on the same date as the other lots (June 18).
:;Both anhuals became heavily infested with ticks and contracted Texas fever.
Calf 946 died July 6. It was heavily infested with nymphs and young adults.
O" .950 was nearly dead July 15 and was killed. Up to the time the animal
*. a killed, 2,960 adult ticks had been collected.

S,. OBSERVATIONS ON ENGORGED TICKS REMOVED FBOM THE ANIMALS.
ee;," ticks were kept in Petri dishes.

I iJifh ryem2ned from. 04 (lot 4).-July 12, 70 engorged and nearly en-
401d1 ticks zwiovedL AU but one of the ticks deposited eggs. 1A good many
i:.eggs shriveled. Most of the ticks died either without ovipositing or before ovi-
ii position:: was completedL About 00 per cent of the eggs hatched.
.. 't. .., .13. ea gorged icks ..rznoved. All but one oviposited. Some eggs
i veled. Thirty-one per cent of the ticks.died either without ovipositing or
bDow oe..:Oslion. was completed. About 10 per cent of the eggs hatched.
|;,, 1, M epgo..:lrxgked and neezry engorged ticks removed. All oviposited ex-
," c.. pt..... Ci foAr per cent q the s died either without ovipositid g or
W.,pol ton.. was completed. About 95 per cent of the eggs hatched. .
. ... ..






18 ACTION OF ABSENICAL DIPS AGAINST CATTLE TICKS.

July 17, 15 engorged ticks removed for study. All oviposited. Seventy-three
per cent of the ticks died before oviposition was completed. About 10 per cent
of the eggs hatched.
July 18, 20 engorged females removed. All oviposited. Sixty per cent died
before oviposition was completed. About 50 per cent of the eggs hatched.
July 19, 25 engorged and nearly engorged ticks removed. All but one ovi-
posited. Small number of eggs deposited. Eggs were scattered and many
shriveled. Twenty-four per cent of the ticks died either without ovipositing or
before oviposition was completed. Less than 1 per cent of the eggs hatched.
Ticks removed from calf 949 (lot 5).-July 12, removed 336 engorged and
nearly engorged ticks. Lot No. 1 of 100 ticks: All but two oviposited. About
half of the ticks died either without ovipositing or before oviposition was com-
pleted. About 95 per cent of the eggs hatched. Lot No. 2 of 100 ticks: All but
one oviposited. About 50 per cent of the ticks died either without ovipositing
or before oviposition was completed. About 95 per cent of the eggs hatched.
Lot No. 3 of 136 ticks: All but three oviposited. About half of the ticks died
either without ovipositing or before oviposition was completed. About 90 per
cent of the eggs hatched.
July 15, removed 49 engorged ticks. All oviposited. About 33 per cent of the
ticks died before oviposition was completed. About 95 per cent of the eggs
hatched.
July 16, removed 119 engorged females. All but six oviposited. About 65
per cent of the ticks died either without ovipositing or before oviposition was
completed. About 85 per cent of the eggs hatched.
July 17, removed 30 engorged ticks. All oviposited. About 30 per cent died
before oviposition was completed. About 90 per cent of the eggs hatched.
July 18, removed 30 engorged females. All oviposited but one. Forty-three
per cent died either without ovipositing or before oviposition was completed.
About 95 per cent of the eggs hatched.
July 19, removed 118 engorged and nearly engorged females. All oviposited.
About 33 per cent died before oviposition was completed. About 90 per cent of
the eggs hatched.
Ticks removed from. calf 943 (lot 6).-July 12, removed 200 engorged and
nearly engorged ticks. Lot No. 1 of 100 ticks: All but five ticks oviposited.
About 65 per cent of the ticks died either without ovipositing or before oviposi-
tion was completed. About 95 per cent of the eggs hatched. Lot No. 2 of 100
ticks: All oviposited. About half of the ticks died before oviposition was com-
pleted. About 95 per cent of the eggs hatched.
July 15, removed 35 engorged ticks. All oviposited but one. More than half
of the ticks died either without ovipositing or before oviposition was completed.
About 95 per cent of the eggs hatched.
July 16, removed 116 ticks. All but five oviposited. About half of the ticks
died either without ovipositing or before oviposition was completed. About 95
per cent of the eggs hatched.
July 17, removed 20 engorged females. All oviposited. Thirty per cent of
the ticks died before oviposition was completed. About 25 per cent of the eggs
hatched.
July 18, removed 30 engorged ticks. All but one oviposited. Ten per cent of
the ticks died either without ovipositing or before oviposition was completed.
About 75 per cent of the eggs hatched.
July 19, removed 49 engorged and nearly engorged females. All but one ovi-
posited. Fourteen per cent of the ticks died either without ovipositing or before
oviposition was completed. About 50 per cent of the eggs hatched.
Ticks removed from calf 950 (lot 3, control).-July 12, removed 200 engorged
and nearly engorged ticks. Lot No. 1 of 100 ticks: All oviposited. Ninety-seven

































Mi-"; (lot 3) both animals became infested with ticks and died of
!iigi',::. ix: a f-ver.
~E' effect on the ticks.-Observations were made from time to time on
S the animals for the purpose of noting any ticks that might show
.evidence of arsenical poisoning. Only a very few dead and abnor-
1 mal ticks were found. A few dead females were noted on calf 949,
I.". good many abnormal young females, and a few dead ticks on
: calf 943, and some abnormal young females on calf 945. It is possi-
,le that these ticks were affected by arsenic absorbed from the skin
i of the animal, but their number, compared with the total number of
t. 'icks present, was so sinall that it may be said that the arsenic, if
t "ive at all, had a negligible effect on the nymphal and adult stages
of the tick. Whether this was also true of the larval stage of the
16 9t "nt" besaid, sine it was not practicable to make observations
n 6: sa, ineeit.
this stage odn account of their small size and the difficulty in find-
ii "r u z u a r .
~them.
,, .. .. .. .... . .. ::
4'A:.. ,xbif itresting abnormality was found in, some engorged females
...dke..fr .i to of the dipped animals. Ten of them were taken from
*kInbn&fn61m ctalf These ticks were plump and trans-





20 ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.

parent. The dark intestinal branches and the Malphigian tubes
could be plainly seen lying in the lower portion of the body cavity.
On puncturing the body wall a clear fluid issued from the body
cavity. Five of the ticks from calf 949 were set aside for special
observation. All began ovipositing, but egg-laying progressed very
slowly and only a few eggs were deposited. None of the eggs
hatched, although some of them developed nearly to the point of
hatching.
Nothing final was determined with regard to whether there is any
relation between the number of ticks developing on animals and the
duration of the interval elapsing between the last dipping and the
date of infestation.
For the purpose of obtaining data on this point approximately the
same number of ticks were placed on all the cattle-that is, larvae
that hatched from 21 grams of eggs. In the case of the two animals
infested one week after the last dipping (lot 4), one became heavily
infested and the other lightly infested; in the case of those infested
two weeks after the final dipping (lot 5), one became moderately
infested and the other heavily infested; and in the case of the two
animals infested four weeks after the last dipping (lot 6), the result
was the same, one becoming heavily infested and the other moder-
ately infested. The two control animals became heavily infested
with ticks.
An attempt was made to obtain additional and more definite in-
formation on the above point by collecting as far as possible all the
engorged ticks maturing on the animals. This was interfered with,
however, by the death of five of the eight animals that became in-
fested, including the two control animals. The results from the
three animals that survived are as follows:
Number of engorged female ticks collected from surviving animals.


While it would appear from this that the infestation becomes in-
tensified as the interval increases following the last dipping, the
data are not adequate for drawing conclusions on this point.
The observations made on the engorged females removed at inter-
vals from the animals (p. 17) were for the purpose of determining
whether any arsenic absorbed by the tick might destroy it after it


Interval
between Number of
No. of last dip- engorged
animal, ping and females
infestation collected.
(weeks).

944 1 906
949 2 4,884
943 4 5,715













































.", : I


:, The mortality here is not nearly as high as in the above instances.

tl unfortunately no ticks from animals not suffering from fever were
i : ::. : .... :.. .. .. . .:: . ..
, bialtble for controls, but it is known as the result of a wide expen-
,.. .with ticks from normal animals that theimortality is abnormally


'The percentage of the engorged females that oviposited is given
'" .. tn U ..following table. 7The ticks were collected from each animal
fi .. July l to 19, inclusive, and kept under observation.

.. *" ..' *"; Percentage of engorged ticks ovipositing.
:A .- '?A A ^ l" .... - . ' ......... . H -. .. __ _, ._


"i:;!:!.:1. '-* :: :*" :' " '* .'; j ~ e = 'r '

A... '. k. : : ..:, ... .m ." . ...... .. .. .
.. .l.S .. . . ...ot ..from" - a -




.. .... . ... ". . . . .... ..:.'.' .. ,. ... ..... .'. .. ..
R7':ii. ". .: ." .':d" ... .. .: . ". .. .. . . . . .."
:!!!!: i: 2" .. ;,;.. :- j .... .... .. . .. .. . l... .....t .. .... ... .
Li:"" -H--. '. ., -, ,.-: --.- --. . .-. .. . ... . . . .


Number of T..orvi-
ticksB. pdtfntg.
_ _ I _ _ _


198
450
2S6


Per cent.
96
98
97
9.


1 . .:......... "


Per cent.
808 1,277 10
792 665 12
684 978 7
08 579 17
742 372 32


Moi :..
!IB .5 :" M ': f *.

E:::i ;: ::. '- v




::39

22 ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.

It is noted from the above table that the ticks ovipositing from
the dipped animals range from 1 to. 3 per cent lower than those
from the undipped animal (control). This difference, however, is
so slight as to have no significance, and it may be concluded that
any arsenic absorbed by the ticks failed to be sufficiently active to
prevent oviposition.
The percentage of eggs hatched in the case of the various lots of
ticks collected from animals that survived long enough for ticks to
mature is as follows:

Percentage of eggs hatching.

Calf 944 Calf 949 Calf943 Cal 950
Date collected. (lot 4). (lot 5). (lot 6). contSo).

Percent. Percent. Percent. Percent.
July 12............................................... 60 95,95,and90 95 and95 90 and90
July 15 ............................................... 10 95 95 90
July 16............................................... 95 85 95 ............
July 17............................................... 10 90 25 ............
July 18 ...----------... ----.... ----.----------..------------.. 50 95 75 ............
July 19 --..-----------------........-..... --------- ...------------ 1 90 50 ............

The percentage in the three dipped animals (944, 949, and 943)
ranged from 1 to 95, 85 to 95, and 25 to 95, respectively, as com-
pared with 90 per cent in the three lots from the control animal.
Because of the fact that it was necessary to kill the only remaining
control animal (calf 950) on July 15, there were no undipped ticks
available for comparison with those collected from the dipped animals
on July 16 to 19, inclusive.
By comparing the percentages for the dipped animals with those
of the control for July 12 and 15, it is noted that the percentage of
eggs hatching from ticks from calf 944, infested one week after
dipping, is low, while the percentage for each of the other two
animals, infested two and four weeks after dipping, is normal. It
is noted that in general the percentages for the remaining dates range
lower for calf 944 than for the other animals. Unfortunately the
percentages for the dipped animals can not be averaged for purposes
of comparison, because the number of eggs in the different lots varied
greatly.
It is evident, however, that while arsenic may have been responsible
for a decrease in the viability of the eggs in the case of calf 944, there
has been no such effect in the case of the ticks from the other two
clipped animals, and, on the whole, it seems safe to conclude that
arsenic has played no important part in determining the percentage
of eggs that hatched.
It should be borne in mind that this result is not contrary to those
recorded in Bulletin 144 of the Bureau of Animal Industry, where
ticks subjected to the direct influence of arsenic were found to lay eggs













A having shown by experiment No. 1 that arsenic has a pro-
action which lasts for less than a week, it was determined to
Suc.. '&other experiment for the purpose of determining the length
0.4OF ..-att arsenic will protect. It was also thought necessary to
thetests showing that arsenic protected against immediate in-
... -Ak since there was a possibility that the results obtained
4 bii t: have been accidental. One thing that threw doubt on the
fla otioned result was the fact that the animals, following the
Slppig and the infestation (carried out on the same day), were
-islow rain, which it was thought might have kept the arsenic
In ^ solution on the skin and created a condition much as if the ticks
hd.i been subjected for some hours to an arsenical dip. In order to
*hii- is possibility in the following experiment, the dipped ani-
...M soon as dry, were placed at once under shelter and kept
ii :: : '" .:! : .i .. .. ......
m:4 _Until, the close of the experiment..
j:.u eiu.perimeat. No. 1 the animals were kept submerged in the dip
'- i twod minutes. As this is longer than an animal remains in the dip
lhnpa.@" .ssing through the ordinary dipping vat, it was determined in
ti fol.owiu experiment, in addition to dipping animals for 2
lu,.t.imt to dip others for 20 seconds, which comes nearer to'the time
S rquinred to pass through a vat.
S The .dip used in experiment No. 2 was made on July 29. It was
made according to the usual formula of 8 pounds of arsenic to the
Ilii:.: gallons. An analysis of a sampletaken on the date the dip was
x ade.. showed it to contain 0.1652 per cent arsenic trioxid. As in
pzp priment No 1, no pine tar was used. Twelve calves were used in
S-the .experiment, divided into five lots as described below. All of the
S.cattle were dipped on August 1. Lots 1, 2, and 5 were infested with
I: b e progeny of-female ticks collected at Fort Worth, Tex., June 24,
I1912. -Lots 3 and 4 were infested with the progeny of females re-
,.eived from Fort Worth, June 29, 1912.
..... ' .!.. *:: : [..if .:* x" '" .. r* : "
4$ ..o 1. Oalves Nro. 957, 9.47, snd 958.-Dipped two minutes in an arsenical
p .. Infested with seed ticks two and one-half hours after dipping. No ticks
b||. elopd. Calves 957 and 947 developed no fever. Calf 968 showed a tern-
i....m'1 .aland'In all probability had an attack of Texas fbver. Calf 947 follow-
dipping msuffered from. anorexia and blet. On August 26 the animal de-
ia oped. a gastric fistula located. on the underside of the abdomen. Food and
...drops of liquid were Issuing from it. On August 29 the animal was killed. The
fitula was fQund to extend ipto the fourth stomach. The mucous folds in the
*i i~~4t flie fistula were hypertrophled, hemorrhagic, and sloughing away.

........: . ..






ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.


Lot 2. Calves Nos. 927, 939, and 928.-Dipped 20 seconds in an arsenical dip.
Infested with seed ticks two and one-half hours after dipping. No ticks de-
veloped on these animals. There was no fever. Calf 939 died August 20. On
post-mortem there was an enteritis, principally of small intestine and cecum.
There was congestion of lungs and a slight congestion of kidneys. Smears from
spleen and liver contained no piroplasma.
Lot 8. Calves Nos. 955 and 942.-Dipped two minutes in an arsenical dip.
Infested two days after dipping (August 3) with seed ticks. No ticks de-
veloped on these animals. Calf 942 showed a rise in temperature from the
ninth to the twelfth day after infestation. On August 6 calf 955 died of
arsenical poisoning. The liver was yellow (fatty degeneration) and very
friable. There were large hemorrhages in the endocardium of the right side,
also large hemorrhagic areas in all four stomachs. An enteritis was present.
There were edematous areas in wall of stomach and intestine. The capsule of
the spleen was much injected. All blood vessels were injected and the blood
was very dark. There were no lesions in the mouth.
Found a number of larvae on the skin, all of which were dead. Two of these
were observed with certainty to be attached.
Lot 4. Calves Nos. 956 and 941.-Dipped 20 seconds in an arsenical dip. In-
fested with seed ticks two days after dipping (August 3).
August 16 found a very young nymph on calf 941.
August 20 removed above tick for examination, and determined that it was
a specimen of Margaropus annulatus. No other ticks were found. No ticks
developed on calf 956. This animal showed a temperature from the sixth to
the twelfth day. Calf 941 showed no temperature.
Lot 5 (control). Calves Nos. 926 and 938.-Undipped. August 1 infested, with
seed ticks. Both of these animals became heavily infested with ticks and
showed a rise in temperature. Calf 926 was down August 22. Had been down
since the previous day. The animal was greatly emaciated. It was killed.
Heavily infested with ticks. There were no lesions of Texas fever. Smears
from liver and" spleen contained no piroplasma. On August 16 both of the
above animals were treated with a subcutaneous injection of 150 c. c. of a 1
per cent solution of trypan blue. Calf 938 was killed August 30 for the pur-
pose of noting whether the stain froni the trypan blue still persisted. On post-
mortem both carcasses were found to be extensively stained. The parts stained
were as follows: The skin; subcultaneous and intermuscular connective tissue:
parietal and visceral pleura and the peritoneum; epicardium, endocardium, and
pericardium; trachea; bronchi and smaller air tubes; cartilage of joints;
capsule and trabeculke of spleen; cortex of kidneys, and the veins and arteries.
A pale-bluish fluid was noted in some of the mesenteric lymph glands.
The post-mortems were made 6 and 14 days after the trypan-blue solution
was injected.
DISCUSSION OF RESULTS.

It is noted from the above results that animals when dipped once
in an arsenical dip for two minutes (lot 1) and for 20 seconds
(lot 2) were protected from infestation when exposed two and one-
half hours after dipping. This occurred when the animals were not
exposed to rain and the arsenic on the skin was not kept in a more
or less dissolved state for some time, as was probably the case in
experiment No. 1.
It is also seen (lots 3 and 4) that animals dipped for two minutes
and for 20 seconds were protected from infestation when exposed two


24
















































glowed nmOugh to cause poisoning. Support is lent to this view
ie1 fat that much, difficulty was experienced in dissolving the





26 ACTION OF ARSENICAL DIPS AGAINST CATTLE TICKS.

arsenic, because the water was not kept boiling. After ail -the
arsenic had apparently gone into solution and the strong solution
was added to the water in the vat, clumps of white particles were
seen floating in the water. The writer at the time assumed these to j
be masses of calcium carbonate thrown down by the sodium carbon-
ate. It was shown that this could not have been the case, however,
by observations made when the batch of dip was prepared for the
next experiment (No. 3). Water from the same source was used,
and no such precipitate was thrown down by the sodium carbonate.
The only conclusion that remains, and this is supported by the
analysis referred to above, is that the particles observed were undis-
solved arsenic. If the conclusions here drawn with regard to the
cause of the poisoning are correct, the extreme danger of havilig
undissolved arsenic in a dip is indicated, and it is possible that an
explanation of losses in certain instances has been furnished.

STAINING OF TISSUES OF ANIMALS TREATED WITH TRYPAN BLUE.

The extensive and intense staining of the tissues of animals treated
with subcutaneous injections of a 1 per cent.solution of trypan blue
has been previously noted in the post-mortems of animals Nos.'926
and 938. The post-mortems were made 6 and 14 days after the
treatment. It would be of some practical interest to determine how
long the staining will persist in treated animals, since it appears that
it might interfere with the use of animals for beef purposes for a
considerable period.
S
EXPERIMENT NO. 3.-CATTLE EXPOSED TO INFESTATION FIVE DAYS AFTER
DIPPING.

Following experiment No4&.another was undertaken to determine
whether arsenic will protect animals from infestation five days after
dipping.
The dip used in experiment No. 3 was made up in the proportions
of 8 pounds of arsenic trioxid and 24 pounds of sodium carbonate to
500 gallons of water. No pine tar was used. The dip was made
August 29, and an analysis showed it to contain 0.1869 per cent of
arsenic trioxid. The results of the experiment were as follows:
Lot 1. Cattle Nos. 830 and 860.-Dipped August 29, 20 seconds. September
4 (five days later) infested cattle with progeny of ticks collected August 8,
1912. at Fort Worth, Tex. Both animals became grossly infested with ticks
and contracted Texas fever. On September 20 animal 830 died. Post-mortem
showed typical lesions of Texas fever.
Lot 2 (control). Cattle Nos. 855 and 858.-Undipped. September 4 infested
with progeny of ticks collected August 8 at Fort Worth, Tex. Both animals
became grossly infested with. ticks and contracted Texas fever.
































:h ....a LW. iuilIn s UueI L) IU iW lt U tai1g Kieiu aunu nUl Lo LLUWe'r
'bei.9ng repelled. The animals when seed ticks were applied to them
' W"ere.. placed in a special pen set aside for that purpose, and several
. hours later, after the ticks had had time to attach themselves, were
A; lced in the tick-free pens they were to occupy during the experiment.
i: I:: arsenicc possessed simply a repellent action effective for two days,
*I complete protection would not have resulted as occurred in the ex-
per iments, since the larvi would iher have wandered about over
S the hair of the animals or have become dislodged, only to become
attached later when the repellent action of the dip had ceased to be
S effective. It is therefore seen that *|we were dealing with a re-
fellent action instead of a toxic action at least a certain degree of
infestation must have resulted in the case of all of the dipped ani-
.mals, unless, of course, all the seed ticks left the animals between
te time the ticks were applied and the animals were placed in their
*. permanent pens, a possibility that is too remote to be worthy of
consideration.
". ..



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:li" ADDITIONAL COPIES of this publication
. .. ,A. may be procured from the SUPEBINTEND-
t,, X OF DOCU,]TS, Government Prnting
i-/ : Office, Wahington,, D. C., at 6 cents per copy

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