Internal Parasites - Jackson County 4

The PracticalGuide
to Equine
Internal Parasites
and Dewormers
Dearhorseowner:
There'sa lot of hypeandmisinformation
floatingaroundabout
thebestwaysto keepyourhorsehealthy it canbe toughsometimes
to
knowwhatto believe.
But let therebeno doubtthatoneofthe mostimportantthings
you cando to helpyourhorselive a healthy,vigorouslite is to protect
- "woms': Thesedestructive
him from theravages
of internalparasites
creatures
takeadvantage
ofthe factthatthey'remostlyhiddenfrom
view out of sight,out of mind.And they thrivein today's
environment,
wherehoNesspendat leastpartof theaverage
day
exposed
to literallymillionsot'parasite
eggsandlarvae.. . just waiting
fbr you to slackoffon yourhorse'sdewormingprogram.Thedamage
theycando is sneakybut canbe significant.By thetimeyour horse
showsoutwardsignsof a severeparasiteinfestation,
he'salready
suffereda greatdeal.That'sthebadnews.
But thegoodnewsis: Parasite
damageis entirelyandeasily
preventable,
with yourchoiceof straightforward
dewomingprograms
usingsafe,effectiveproducts.
All youhaveto do is choosea program
thatfits yoursituation,andstickwith it.
Do you needa collegedegreein parasitology
so youcanchoose
yourhorse'sdewormingprogramwisely?No. All you needis reliable
information,suchaswhatis providedin thisbrochure.It's plain,nutsand-boltstalk abouttheparasites
thatthreaten
yourhorse,andthe
compounds
availableto controlthem,to helpyou separate
thefacts
from thehype.
KarenE.
TABLEOFCONTENTS
For additional copiesof this booklet,pleasecontact:
DEWORMINGGUIDE
Sedes
SpinworksEquineEducational
301W. Osborn
Phoenix,
AZ 85013
i--r
!:-'
Or Call:
-2162
(602)2O'7
(602)20'7-2109(fax)
We will sendup to five additionalcopies
Iree,whilesupplieslast.For orde$ of si^
andmore,pleasecall (602) 207'2162
.1
INTRODUCTION
Parasiteshdvelong beena problem for horsesand horseowners
alike. In the "old days"hoNesbecamelame, lost weight, suffered
severecolic and evendied becauseof woms. Horse ownerstriedjust
abouteverythingimaginableto relievetheir horses'plight of pests,but
oltentimesthe cure was worse than the disease.
Thankfully, advancesin scienceand sanitationhaveallowedus
to contfol thesenasty and unfortunately- naturalpafts of a horse's
life more effectivelywithout inflicting more damageand sufferingon
your belovedcompanion.
Large strongyles,horses'one-timearch enemies,havevery
nearlydisappearedthankslargely to ivermectin.But we must remain
vigilant. Large strongyleshavenot completelydisappearedfrom the
planet,they're simply waiting for us to drop our guard-The best
defenseis continueddiligence.
But with allthe productson the market,it's sometimesvery
difficult to figure out which are the bestfor your horse.This booklet
was designedto help clear up someof the confusion.ln this special
report,you will be given full descriptionsof eachparasitethat plague
our horses,plus a chart showingexactlywhich productscontrol that
pest.Thesepagesare organizedalphabeticallyby common nameofthe
parasite,but the Latin, scientific,nameis also given, so you can
undentandadvertisements
and packagelabeling.
We've also includedsectionson generalcontrol of parasites,the
classificationsofparasitesand dewonnersand evena little horse
anatomy.
Keep this booklet handy when you are evaluatingdewonners.
It'lI help you betterunderstandwhat is bestfor the healthof your horse.
If you haveany questions,ask your vetennarran.
Tlpes of Parasites
A parasiteis anyliving organismthat lives off anotherliving
- in this case,yourhorse.Horsesplay "host"to many
organism
differentpansitesandgetnothinggoodin retumfor theirhospitality.
Therearetwo differentkinds of parasites:intemal andextemal.
Intemalparasites,
or endoparasites,
live happilywithin thehost'sbody.
This bookletfocuseson thoseintemalparasites
significantto
horsesandtheirowners.
Scientific namet Paruscark equ.tun
Commonmme: Ascarids,
Roundwo.ms
Physi@l desoiption of par.site:
Ascarids.
or roundwonns.
a.ea
rigid,heavy'bodied
worm.Adults
canreachup to 50cm long(about
20inches).
[ffect€ of paralite if left untreated:
Ascdidsareespeciaily
dangercus
lo foah aged6 nonlhsor
youngerSeveEinfectionin
hosesthisyoungcanbuildup
quicklyandlead1olilerand lung
da'nago.poor overall growth and
As rhe larvaeare noving through
thebloodsystem,
tbalscan
expe.ience
coughing,fever.
p.eumonia,bleedinglungsand
olher respi.atoryinfeclions.
Asceidsin tbeadultstagelive in
thesmallintestinewherctheycan
causecolic,blockaSe,
ruptured
StageMifecycle:
Adultfemaleascarids
lay eggs
whicharcpassed
in nanureto rhe
paslurewherethey developinto
irlictive larvaein l0 daysto six
weeks.ThehoBeswallowsthe
lanae,whichhatchandbunow
inrolhe wallsof theintestine.
Fromthere.theyarccariedby
thebloodsrcaminlo theliverand
lurgs,thenmoveup theho6e\
windpipe.The honecoDghs
up
thelarvaeandswallowslhem
dgain.Theymarure1oadDltsin
thesmallintestine.
Severelyintbctedfoals may
experience
alternadn8
bolB ol
foul smellingdiarheaand
consripation.
Infecredl'oahcan
loseweight,butmayhavea pot
belliedexpenence.
Theyotien
Hoa the parasite enters the ho$e's
Tbe horeeswallowsascdid ldvae
ashegraas on infectedgas in
Ad!lls
equotun-13
Larvae
lenbendazole
ivermeclin
m0x0ecItn
oxiendazole
oxibendazole
pyrantel
pamoate
ovrantel
tartrale-dailv
pyrantel
lartraie-slngle
I
13rorprolucrbEndnames
Conrror:Seepaqe
Larvae
Sciediitc Mme: (turr.?/,ilts h1t.tt nlut Is.
phccnrenL.C tr.stttrld ldY uP
to 1.000pelc ycll$v egeson the
hosc\ tu,elegsand nmulders.
Moisrurerrd iiidbn ironr thc
ho6e lickins nselfcxusethe eggs
to haLchin aboutscvend.Ys.
G. drdlit hys aboul5(10Yellow
cggs aroundthe chin md thro.l ot
rhe losc.These egesarc !q!
dcpendentor thc ho.s€ lickntB
rhenrro halch.Alier hrlching.
C. ril.srtz/n- hNac urc licked
inr()rhe nrouth.C. ndrdld buros
u n d c r t h es k i nt o t h c m o u L h . l h e E
wanderingthroughlhe noudr i(tr
$out a N)nth bclorc nriSratinglo
rhc sLodNh for olen'inlerire.
CommonnanrerBot flres
Physi.aldcscriplionof parlsile:
.^dultfliesarcb,own.h.iry and
beelikc-wnh onePlir ol wings.
andneasureaboutl/4 . Thc hrvr
(bot)is d$ l/4 longsith d
narcw. hookcdcnddd a brcad.
ft)!.dedLrody.
After! lhreewcckdcvcbPnrenlal
pdiod ir thc nanrth.bot fly larvdc
G. rtt?s/nurrr
of bodrspecics,
andG. rrrali!. Bigrateandallrch
to thc mucu\liningof
nremselves
thehorses stonrrh andrcnrarn
rhee durinrrhewinrcr'Alier
abourl0 nonths.lheYdet.ch
irolr drclinnrgandrrE Pa\s.'lout
of thcbodYlhroughLhefeces.The
hvae burow inlo lhc grounddnd
on the
maturc.Depending
cordilions,ndultsenrcrgcrn three
Adult icmrles
Io l0 rveeks.
deposneCgson rhehotscs lcgs.
.hin,lhroalrnd the
shoulders,
on geogr!Ph!c
lips.Dependrng
locath!, thelil. cycleofbor tlies
i\ nol fixedto only cerrainlLmes
ofthc yelrrnd borlrrvaccanbe
actilc in hoseslnywheretionr
Atrgustto MrY.
Hos the parasiteent€.sthc horse's
EfTcctsor p$asitc if lett un(reated:
Horsesthlt sltw no oulwa.d
signr ol illnesscan be severelY
infesred.Bivins no.lue ol thc
Potenliuldamge occu.nng
inside.Howcver sone ho$cs do
show sig.s of infenaiion,
i.c1udi.g.r intl!med mouth alea
and stomrh irrillition. lnleslltion
with bot l.rvac mly causeholcs
i i l h c s t o n a . hl i n i n S . l f l h c
inlcstrrn)n is sevcE.lhe oPening
liorn thc slomr.h Io drc inlcsLines
mey bc blocked,which.dn c.usc
ifinriotr. ulcea rnd clcn colrc
Thc burowing lNrvlc crn cxrse
small teaB in lhe skin, which can
bccomc inlecred. Divc bombing'
ldult flies causelerlousncss in
tjgg laline beginsin crriy
sumnrcrEggsofrhc diliereDr
dificr in colorrnd
species
e
oxibendazo
-
brandnames
l coniroi see page13lorproducl
5
_r
S.iennfi c nan'e. Ttit host ran8! Ius ar ei
Commonmmer Hairwoms
Physicrl description of parasite:
Theadullwom isriny (0.5cm
long)andhai.like.
Theadultwormoccursin the
slomachandin thesmall
intestine,
initatinganderoding
thenngeFlikeprcjecrions,
or
villi, ofthe gur,drmagingthe
capilldiesa.d lymphvesels
withinrhevilli.
Hor th€ parasite ent€N th€ horse,s
Theho6eeatsgrasses
infected
with eggsof thestomacb
hair
sorm. The eggshabh andthe
laflaetuovei.to tbesrornach
vherc theymaureandIaymore
eggswhicharepa$edin 1he
EfTectsof parasite if teft untreated:
when a horseis infectedwirh
hanwoms. he is usuallyalso
infectedsith otherwoms.
Damagecausedby the hair worm
canbewoNenedby orherworms
in thesystem.
Signsof infecionnay bedark,
foulsmellingdiafthea,because
thedamaeed
villiare unableto
digeslandabsorbproperlyin
If thereis severedamageto the
villi. theunderlying
smallvessels
couldbeddmaged
aswell.
.aljsingbleedinginrorhe
rntestines.
BleedingmayIeadro
anemiaaDdlos ofcondition.
Foalsarcveryopento infection
by hai. worms,sobroodmares
shouldbedewonned
md noled
Trichostrongylus
axei-adulls
lenbendazole
ivermeclin
moxidecltn
oxJendazole
oxibendazole
pamoate
PVrantel
pyranlel
tartrale-daily
lanfate-single
PYrantel
T---
conrrcl:Seepase i s tor produci
Scientilicname:,JrDzg/lrd4 rdrcri
Comonnsme: lntestinalThreadworms
Physicrl d€scription of parasite:
Threadwormsare long and han like. Adults grcw to be 8 to 9 mm
in lenslh(about2/5 inch).
Strges/lifecycle:
Larv@malureto adult worms in
rhesmallintestine.
Infectioncan
occu. by eatinginfetive ldvae
or by penetrarionrhroughthe
skin. lf the larvaeenler the
horse'ssystemthroughits skin,
they moveto the lungs,thenup
the wind pipe wherethey de
coughenup and swallowed.Thel
malurc in the small intestine,
whereadult femaleslay the eggs
that are pased out in the mmue.
Eorr the parasite enters tbe horse's
Th€ infectile laJ!?eof the
threadwom car eitherbe
swallowedby fte horseor lhe
lN& can go throughthe ho6et
skin.Youngfoals can alsobe
exposedto the wom by nD6ing
from their i.fecled Dothers,
--
Eflects of parasite if left untnated:
If the larvaeenterthroughthe skin
the next stopis the lungs,rvhere
bleedinedd
theycancaDse
respnatoryproblems.
Inflammatioa
and6hes can
developwhercthe ldvae
penetraredthe skin,
The wors! damageoccun in
untreatedfoals-InfectedthrouSh
their molheG nilk. they can
sufferdiarhea, weaknes, weighl
los dd failure lo thrive andg.ow
at a normal rate.veterinuians
generallyrecomend deworming
your foal eaily in life and asoften
aseverymonth urtil weaningDiarheain 7-l0 da! old foals
may be causedby inteslinal
threadworms.DewoDing may be
beneficial
in thesecases.
Be very cdeful to Gadyour
dewormer\ label- some
productscannotbe usedon foals
6S
\<WZ::/
l contrcr:seepage13rorproduct
band nam6s
7
Sci{tificnime:,Jr,rn8rl&r
valsala,
S. equinas,S-edentatus
Conmon Dame:LargeStrongyles,
Bloodworms
Physical dsqiption of paruire:
Largesrongyles d€ long. fat
woms with bitingmouths.Since
$ey are full of their equine
victims'blood,theyusuallyarc
reddish-brcwn
in color
St{gen4if€cycle:
Eggsof fte threespeciesof Iarge
srrongylecandevelopinlo
infecdvelarvaeon pasturcin as
little astbiee daysif w.m, noht
conditionsexisr.Oncethe laae
haveb@nswallowed,the larvae
drop their protectivecoatinS,or
"shealh', on thei. bodiesod
mig.areto differenrorgansfor
funher development.The leae
of .ttrcrpkr ,!la..tr, the most
hamflll of the tbree,movero the
hose's aiterieswherc tney'?o
wilh the flow" ofthe blood for
approximalelytwo weeks.Wlen
theyreachthe mesentericaJtery,
the dain anery that foedsthe gut
dea, they stay therefor
approrinately lour nonths while
lhey continuegrowine.Thenthey
retum to th€ ldge inrestine
tbioDghthe.iteries. Oncein the
lmgeinEstine, the iN@ bumw
into the intestinalcavity.Afler six
to eight monrhs.the eorms re
maturcandeggsbeginto pass
itrto the mure. .
moveto theliningof ihe
abdominalcavily wheE lhey form
nodules.The larvaedso fom
nodulesin thegut wall,which
they breat opento seryeasa
dooNay inlo the ldge inrestne.
Hor th€ prrrsite enaersthe horse,s
Largest.ongylelawae live in the
manuc in the grass.When the
ho6e swallowsinfectedgras, the
growing proces of the woms
f,ffects of pamsit€ if left untreat€d:
Of the threespecies,Sr@rsrtur
vrlaarir doesthe mostdamage.
Thafsbecause
thisspecies
uses
anddamages lhe blood system
d it movesaroundth€ horse's
body.During theii wdderings,
the laJvaerough up the walls of the aneries,leaving"tracks" in
thelining.Thesetmcksee
perfect spotsfor blood clors.The
clots breakawayfrom the walls
dd lodge in otherblood vesseis.
blocking the blood flow to rhe
intestinebelow the clot.
The rough walls ofblood vesels
not only promoteblood,clor
development.but also wealen tbe
walls.Ifthe blood-vessel
wall is
weak€nedenougb,il cd burst,
causingimmedialedeath.
If thebloodclotsblockblood
tlow to tbe hind qDartes,
lanenessand/orweakness
caD.
Strcngyl6 eq ausfu\e no\e
to the liver after lhey hav€shed
their protectivecoating.They stay
tl|erefor atprcximately six
weeks,thenmovethroughvarious
abdominatorgds to the large
intestine.Afrer abourninemonrhs,
adult wom lay theAeggs.
Wte. they set up housekeeping
in the large iDt€stine,the worms
literally bite otr piecesof it. This
may teadto severecolic, didhea"
fever md memia nom tle
bleeding"bite wounds"in the
stomach
andintestino.
Strcngybs eddtatB alsomo\e
to $e liver wheretlley r€mainfor
appronmatelynine weks, then
Ldge st ongyleswerc oncethe
mostcomon md mosldangerous
equinepdasite. Tlh is no loneer
trDe,thmks 10educalionof horse
ownersanddiligenlde*omins
praclices
usinghighlyetrective
dewonneF.
As longaswe
continueheseg@dpraclices,
there'severyreasonto beliele
that largestrongyleswill not
resune their role asa major cause
ofcolic. BULifwe let up,they'll
Theothertwo species,,S.
?4rin!r
0d.t edenral4r,
cancauseliver
3. vulgaisadults
S.vulgaisL4arteial
lenbendazole'
ivetmectin
moxidectin
0nenoazore'
oxibendazole*
pyantelpamoate
pyrant€l
tadrate-daily
pyrantel
taftrate'sjn0le
f
'l codot: se€ page13icr p@doct
bEndnames
S.vulgaisL5arterial
'
- S.equinus
S.edentatus
S.edentatus
l|ssue
adults
adults
Scientirtc ''ame: Dictlocauta amfe ldi
Comon namerHolseLungworms
Physical description of psrasite:
Thehose lungwomh longand
slender.measuringaboul2 inches
(251o70 nm).
StlgBnifecycle:
The laae go throughthe walh of
the intestineand into the
circulatory system.They are
carriedin rhecirculatory systen
intorhelungs.wheretheymaruc.
The eggspds thrcughthe horse\
systenthroughthemanure,
How the parasite enters the horset
Femalelungwomslay eggs
conlaininSldvae. The horseeal!
the eggsof the lungwom otr
damPglasses.
pyrantel
larlnte-single
f
10
J
conrrd see paqere tor productband nam€s
Efiects of parasite if left untreaaed:
If thereare largenumbeBof the
larvaeprcsent,the lining of rhe
smallair sacsin thelungs,called
the bronchioles,may becoDe
iniratedcausingthehorseto
havea severecough.difiiculty
breathingand los of appetile.
Thesede signsof bronchitis.
Infectionis lsually ligbt in older
hoses becausethey develop
resistanceto the parasireand
usuallyhaveno signs.Iffoalsde
intlcted,theycoulddieftom a
lungworminfectionbecause
lhey
hrvelessiDmunily.That'swhy
it's a good ideato sepa.ateolder
horsesfrom younSfoah and to
maintaina regulddeworminS
Scientifrcname:Oacl,.eta spp.
Common nam.: NeckThreadworms
How the parasit€ €nters the hoN's
Thehose is bitt€nbYaninfected
midge.The laflae aredePosiled
intothebitewound.TheYlravel
ro fte ligamenlsin the neckand
can also be found in the flexor
anosuspensory
tendons
panicularlyof (he
ligaDenrs,
Physical descfption of Parasite:
Neckthreadwomsde longand
is
coiled.The maleof thesPecies
shoner.being6 to 7 cm longand
the femalebeing up to l{J cm
Stageslifecycle:
Unlikemanyof rheothe.worms
that dlTeclhoses. the neck
hasan indirectlite
lhreadworm
cycle.Thatmeanstbepdasrte
organ'smlo
on another
depends
the
horse.
ln
the caseot
it
to
8et
necklhreadworms,that otber
species
is fie bilingmidge.The
neckthreadwom microfildiae
u.dertheborses
livein rhetissDe
skin and m pjckeduP bYthe
nidge whenil feedson the ho6e
The microfildiae develoPlo
infectivelaNae in fte midge\
mouthsilhin 25 days.Themidge
bitestheho6eagain.
Eficcts of garasite if left unt@ted:
and
Adultwonnsin theliSaments
causeswellingandPain.
tendons
Therecanalsobe bumpsunder
andlendors
theskinon liSaments
causedby the hardeningof dead
worms.Ifthesebumpsdisrblethe
norse,surSerymay be necessary.
of lhe adult*orms
Thepresence
nay alsocauselaDenesmd
swellingof the ligaments.
nay invadethe
The microfilariae
lensof theeye,causingirilation,
blindness.
s*elling andsometines
in thetissue
Themicrofrlariae
underrhe skin may also cause
skiniritalion.
oxibendazole
f
l conlrc: see paqe13lorprcduot
11
ScientificnamerO.rrt/a zqri
Conmon nane: Piiwo,ms
How thr plrasilecntcrs the hone's
Physicaldesoiptionof plrasiie:
Thc fcmalepinwo,n givcsthe
specres
r1sconnnonname,duero
hercnaracteristically
lone.pi.
like tail andluge body.Fehdles
canbc aslonSas 150Dm (abotrr
6 inchct in lengrh.The fiale
piDwormis muchshorter.
reaching
a naximun lenethof 12
mm (abourr/, inch).Pirwom
cggsaE wlirish leilow in color
andad usuallylbundin masscs
ncurthc horses anus.
Thehorsebeconres
intcctedwhen
he irrgests
egesthaLhrvedrcpped
iDrofeedo. water
Dftects of parasite if lelt untreated:
Mostof theeffecLs
of pinworm
iniecriondreon theho6e\
appea..nce
andconrtbrtlelel.
Heavilyinlcctedhorsesmuybe
DeNous
rn'l nly dccrease
earing.
Thesevercitchingnrlcs lhe
horserub hisrailandrumpso
relentlcssly
tharrhetail hairs
br€akofT.Thisconditionis.alled
SlaeeMilecJcle:
Larvrenaturcin thelarye
inlestine.
teedingo11theinteslinrl
liningtbr four lo frvenonrhs.
AdultIehdleworns nove ftom
the1a€eintesrine
r{rrhehorscs
anrl ared.Thee$s shelxysare
covcredwi$ asLickyfluid that
catrses
sevcrcitchirg.
AOUrc
L4larvae
fenbendazole
moxidectin
oxibendazole
pymnlel
pamoate
pyranlel
tarlrate-darly
pyrantel
gle
tartmte-sif
f J
12
conrd seepasetsrorpoductbdndnames
Aho, rubbing.bitingand
scrdtch'ngcan
openup Lheskin ir
thetailandrml!E! ro infecrions.
Sci€ntific name: Clatroslo,ds.
'ftere
arc nearly40 ditferenr
spccies
of wods rhrt makeup
thisgroupconmonlycalled
smaustrongyles.
Comnon name:smallsrrongyles
Physicaldesription of perasite:
Ofienbrighlrcd in color,adllt
worns ranSein sizefron 4 mn
to 26 mm (aboutl/8 inchto
I inch).
StageMifecycle:
Theadultfcnralewornlrys her
eggsin thehone'slargeinlesrine.
Theeggspassfiom theho6e in
mrnur, thenharchinlo lafl.e
andndtnrethroughthreestages,
thelastofwhich,L3, is infeclive
to horses.
Lr ldvae altachlheD
selvesro gras andareeatenby
thehose.Aftera ho6eswalloas
theseldvae, they buflow into the
intestinalwall, matureand
emeryeintothela.geintestine
wheretheyleedandlay egss.
Etlects of parusite if left Dtreated:
infectedwilh
A horseseverely
snall strongyles
cansufferweight
loss,dimheaandcolic.Howevea
nost infesrations
de
'\obclinical",meaningthatthere
de no ontwedsignsof the
damage
thatis occurrirginside.
New researchshowsthat
penetralionof the ho6e s
intestinal
wauby smallstrongyles
contributes
to thediseas€
that
haslraditioDally
beenconnected
to larval€mergence
into fte
largeintestine,
Signsof infection:
areauowed
Ii srnallstrcngyles
to rh.ivein thehorse'ssystem,
hecansufferfromseighl los
(b€cause
nurrients
arcnol beinS
absorbed
inro
his
system
\
los of appetite,
oprimauy),
dianhea.andor colic.
How the parasiteentersthe horse's
Theyenterthehorses sysiem
thrcughthetitouthwhenrhehose
paslure.
greos on larvae-infected
adults
taruaLsages,benzimidaTole
encysted
lale
L3/14larvae qeneml
rcsislant'
fenbendazole
ivermectin
moxidectin
oren0azoe
oxibendazol€
pyranlel
parnoale
pyramer
anrale-oafly
pyranlel
hrlrate-sinqle
f
J Conlb: Se6paq613rbrpoductb€nd names
13
I
S.tennfrcMret Dnschia nEsastotnu&
Habrcnemanuscae
Comnon nme Ldge monLhstomach
Physicaldesription of pr.asit€:
Adult wormsde whitein color
andabout10to 25 mm long
(aboutl/8 inchto I inch).
StageMifecycle:
The ldvae of thesepdasiles de
i.gested by lhe comnon housefly
or stablefly naggots,which
developin manure.
Thewoms
developinsidetheflies'naggots.
Thefliesmaturcandthendeposit
theldvae on thelips,nosrils,
woundsrnd othernatudllymoist
deas of the hose. The laNaemay
stayin thema of thewoundor
may be swallowedby tbe boNe.
HabronenaL3 DraschiaL3
Laruae
Laruae
fenbendazol€
ivermeclin
moxidectin
oxfendazole
oxibendazole
owamer
oamoare
ovrante
lartrate-dailv
owanteL
lanrab-sin0l€
f----l
14
contfur:seepaqe
roiorpoducrb€nd namas
How the parqsite enters the horse's
Ii the horselicks the infesleddea,
the larvaenature in the horse's
stomach.
OtheNis€,theystay
in the wound dd createoozing,
expandrng
sores.
Effects of pa.asit€ if Ieft untrcated:
A sndl woundinfecEdwith
Habloaehn andD6ch ia lN^e
cang.owmuchldger andthe
larvaeprevenlhealing.These
chrcnic,non-healing
woundsarc
commonlycalled'tummer
soreJ.Lane deposited
in the
eyescd caDse
conjDnctivilis
Gweuingof themucusIiningof
the eye lid9. trdae that are eaten
cancauseSasrritis
andthe
fomution of tumorlike growths,
whichnay ruptDre.
Scientilic name: Arlpld.rr' hala petoliata
Common Dame Tapewonns
Physical desoiptioo of parAitel
Tapewomshavefl attened,
bodies.The"head is
segmented
circularin shapeud amed with
four sDcte6.Sone tapeworm
species
canbe aslongas80 cm
(32 inchet.
StageMifecycle:
EgBsdevelopin theintermediate
host,lhe oribatid "gasC mite,
over. two to four monthperiod.
Whentheinfecedmitesare
swallowed,the tapewormsmature
withinthehorsein four to six
Hor the parasite getsinto th€
Horseingestsinfecledmites.
EIIects of parasite if left untr€.ted:
A severecaseof tapewonn
inbstationcancauseinrestinal
initation,whichcanleadto
infl ammadon.bleeding,and./or
ulcersof theintestirc.Fatal
intestinal
blockagecanoccuras
thewoms accDmuiate
at the
junction- three-way
ileocecal
junctionbelweensmallintestine,
ldge intestine.
andcecun(the
horse\ verylargevenionofour
tiny appendix).
ConlrolNote:Curentlyrhercare
no dewormensoldin theUnned
Stareslabeledfor Tapeworm
control.However.
someclinical
lrials havedemonstratedvarying
effecriveness
usingpJlaarel
panadrz dewormers-Consult
yourveterinarian
for h€lpyirh
tlpe{om trearmentandconirol.
Deworming
Methods
Thereareat leastthree
waysyoucandeworn
yourhoffe:oralbroad-spectrum
deworming,
ro1x1ion,
anddailydeworming.
ORAL BROAD-SPECTRUM
DEWORMING
Pastewormershavebecomequitepopulff
amonghorseowners
who maintaina regularschedule
of oraladministration
with a premeasured
syringe
conraining
d broad-specrrum
dewo'merLach.) rintsr
hasa full dosein eithera pasteor a gelcompound.
ROTATION
t your veierinarianrecommendsrotating
dewomersfor your horse,oneof the thingshe or she
maybetrylngto preventis "resislance'l
Resislance
rna
parasire
populJrion
de!elopsbecau.erhe'earer liw
wormsihai may survivetreatmentwith a produci.These
survivors
breedandtheiroffspringinherittheabililyto
survivethatsametypeof dewormerBy rotnling
between
chemicalclasses,
it is hypothesized
thaltbe
first groupof survivorsmay be killed befbretheybreed
Inorewormsthatareresistantto the dewormers.
lfyou choosethismethod,be su.eto rotate
between
differentchemicalclasses,
oryou nraydsk
parasites
losinganybenefitsofrotating.Resislant
are
resistant
to wholeclasses
ofdrugs,notjuslsubclasses
and/orbrandnames.
Forexample.
ifyou re rotatingbetween
an
productandmoxidectin,
youarenot
ivermectin
r$o drferenr
rolalrng
ber$een
chemrcal
ch::es..ince
bothareclassified
asmacrocyclic
laclones.
Research
hasshownthatparasites.
specincally
smallstrongyles.
candevelopstrainsresistani
lo
dewormers.
In fact,resistance
hasbeenshownto occur
with mostoflhe benzimidazoles
andalsoto pyranlel
pamoate.
Thedrugssimplylosetheireftectiveness
whenthishappens.
Thats why yourveterinarian
rnay
product,
recommend
rotationbetweenan ivermectin
suchas ROTECTINo I , and a pyrantelpamoale
product.suchasROTECTINo2. Thesetwo arein two
distincdydiiTerent
chemicalclasses.
As anadded
bonus.ivermectin
containsa boticideandhas
mainiained
its statusasa resistance-free
dewormer
Currentlythereareno dewormers
soldin the
UnitedStateslabeledfor tapeworm
control.However,
someclinicaltrialshavedemonstrated
varying
effecri\cne*usingp),rrr4 pdnutc dewotmer'.
Consultyourveterinarian
fbr helpwith tapeworm
treatment
andconaol.
Whateverthe reasonfo. dewoming, you must
paycarefulattention
to these.rson
andtheparasites
thatareactiveduringrhaliime.ln colderclimares.
bot
season
is at its peakin earlyfall $d latewinter.
However,dependingon thc geographicalregion,bots
problem.A! a minimum.makesure
canbe a year-round
theproducts
in yourrolarionschedule
includea
boticideduringthistirneof yeal
DAILY DEWORMING
STRONGID@C and STRONGID@C 2^.
which containpyranteltartrate.are daily dewormers
administercdin the feed.
Many ho$e ownersuselhe daily methodof
dewoming becauseit deliversconstantchemicalkilling
of parasites.Pafasite larvae are killed before they have a
chanceto reproduce.which decreases
pastureconlami
nation.Ivemectin and moxidectincan also kill
inrmaturepamsjtelawal stagesbeforethey rcproduce.
One potenlial problemwith rhe.daily
dewonningmethodis that it nay be difficuh to be sure
youf honjeis eatingall the deworner wilh his food.
Even if other horsesappear to like the tnsle of the
product,everyhorseis diterent. And in situationswherc
horsescan interact wilh each other at feeding time. your
horsemight get chasedaway kon his neal beforehe's
eatenall his daily dewomer Keepaclose eye on his
daily intaketo makesurehe s gettinghis full dose.
Costcan also be a factor in clroosinga
dewomer progran. A recentstudy conductedby the
Horse ResearchCenterin Ocala,Fl., lbund that singledosepastedewormersare considerablyless expensrve
than daily dewormers.The monthly per ho.secost for
the daily dewormingprograrnin this study was $17.78,
comparedto the $3.33 monthly expensefor the paste
A l s o .p l r a n r e lr a f t a r ed o c . n r h J r e . 1 )
TUBING
ln the noFso-olddays,veiedna.iansrelied on
the practice of "tubing" to gei the dewormers into the
horse'ssystem.The technique,which involvesinseting
a tubethroughthe horse'snost.ils and into the horse's
stomach,is now consideredto be outdated.
'"fhe
tubing technique is rarely used anymorel'
.dd Kffen E. N. Hrye.. D.\.M.'Ihere e orhe.
methods now available thal for most ho.ses are safer
andjust as effective.if not more sol'
Researchhasshown tbal tubing is no more
effectivethanoral dosing- and it's cerlainlynot
worth the risk.l
@FoTECTIN
sa regslered
lrademark
oilrcAnmaNoallh,
lDisa registarcd
@STFoNG
lrademark
0t Ptizer
16
Five Stepsto a Single-Dose
1 , Setthelockonthedisposable
plunger
foryour
horse's
correct
weight.
2, Make
sureyourhorse
hasno
foodinhismouth,
orhemightspit
it out- withhisdewormer.
thesame
3, Face
direction
asyour
horse,
infrontofhisshoulders
withhishead
overyour
shoulder.
Useyourfreehand
tosteady
hishead.
4, Gently
inseft
thesyringe
into
P h(tr d,o tttt t)f naoJ An irt t H & hh
theside
ofthemouth,
behind
theincisors
andcanine
teeth
andinfrontofthecheek
teeth
your
(where
thebitrests
when
horse
iswearing
a bridle).
Itshould
beangled
toward
theback
ofthehorse's
mouth.
5, Push
theplunger
onthesyringe
todeposit
thedewormer
on
thetongue.
17
Deworming
Compounds
There are cunently lbreeclassesof
dcwormersavailablethat are effectiveto lome
dcgreein conlrolling borseparasites:macrocyclic
hctones,pyrimidinesand benzimidazoles.Each
classis likc a hmily, consislingofchenical
conpotrndsthat sharecommon structuresand
cornmonnolecules. However.you shouldnote
thr! effectivencsswithin chemicalclassesvaries.
DETAIS_
DrwonulilG
( p e r e g i s l e r el adb eal n dF 0 ls u m m a r i essi n; g l e - d 0aspep l i c a l i 0 n )
iverneclin
mo{hclin
$||antelltdc
{dallr)
Manldbnnb
0aily
orllenftrole
lenbrndflolc
(1)Four
montlrs
oi ageoro der
provde84daystronqyLe
(2)Forbroadest-speclrum
control,
useivermecln
every
elghtwoeks.
vermecln
hasbeen
shownlo
iecalegq
(Study
on0!ESTF010876'E-US-5-94
thiscontrol
is1orony on0parasileand
shoud notbe
c0unlsuppression
desiqnal
)Noweve(
wilhbroad-s0eclrum
cooiro.
coniused
0arasile
(3)Fourlimesperyearodlyiorstronqyleieca
(!!!_!3rasitc!!!)in0 aberecommendation
l0roveral
egqcounlsuppress0n
Tapeworms
noroqislercd
abelc a msloranyproducts
C0nsullwilhyourveiernaran.
isa reqistered
lrademark
ol Farnam
Compan
es,lnc.;@EoU
N4ECTRIN
sa reqd0r0dlrademark
oiHorse
Neallh
Produclsl
OZIMECTEFIN
is a reqistered
lrademark
0l MerialL miled;TMoUEST
is a lrademark
and@BENZELM
lNis a rcgistered
lrad-onrark
01ForrDodqe
@EoVALAN
Animal
Feallhi
DEisa reqistered
lradomarks
ol Plzeri@SAFE
GUARD
isa regislered
lmdemark
oi Hoechst
Ceanese
@ANTHELC
'CIDEs a regslered
isa resislered
trademark
ol Hoeclrsl
AG;@EoU
lndemark
01A0riLabonlories;
@MANNA
Corp0ration
@PANACUF
PFoFoAL& H0RSE
PELLET
DEW0BIIEF
isa reqistered
tradomark
oi Manna
ProCoQomtion
MECoEoUINEW0RMEB
PELLETiSa
producr
l,VoFlLlER
FINACoLT
ANDH0RSE
sa reqslered
lrademark
ol Purina
Mils, nc.
oj Kaeco
GroupInc.t@PU
18
I
I
I
Debugging
DewormingLabels
What's Lurking In the Fine Print on YOURDewormer?
Make Sure You're Getting
Broad-Spectrum Control
Look caJefullyat the parasite
speciesand stageseachproductsaysit
will control. Somedewormerstarget
only a half dozen internalparasites,
while othersare effectiveagainsta
much broaderrange.
What's ,lor on fte label can
be imponant. too.lf a dewomer
"bots'l for example.
doesn't mention
there'sa reason.Somedewonning
productsdon't havea labelclann for
controlling bots. For a productto
control bo!s, its label must say
"boticide .
To maximize parasite
protectionfor your horse.look for
productsthat off-erbroad-spectrum
conrrol. Ivermectin,for example.is
effectiveagainst34 speciesand stages
of pirrlrsitesand is a boticide. A very
effecliveboticide,ivermectin,conlrols
all stagesoflhe two most common
Bewsreof Age Restrictions
Youngfoalsareparticularly
andthe
at risk from intemalparas;les
consequences
canbe g.ave.Foalscxn
be treatedat 7 daysofage io help
prevent"foal heatdianhea"whichcan
be associatedwith St-.,rs)r,td€s
rresi?ri(intestinal
threadworms).
Anotherexample
is ascdids,
or roundworms.
whichcancause
seriousproblemsfo. foals.
however
Not all dewormers,
arelabeledfor useon youngfoals.
Scanthefineprintfor age.estrictions
product.
beforeselecting
a deworming
is restricted
Moxidectin,for example,
4
againstusein foalsyoungerthan
months.Products
thatarclabeledas
safelbr useon lbals wiihout age
reslrictions
canhelpprotectfoals
duringthiscriticalearlyperjod.And
remember
to checkwhichparasites
are
controlledby yourdewormer
Scrutinize Duration Claims
InvestigateDosageand
WeightInstructions
Dewormingformulations
vary,so readthoselabeldirections
cdrefullyto makesureyou'regiving
theprope.dosefor yourhorse's
weight.Eachsingledosesyringeof
ZIMECTERINcanbe usedto treat
onehorseweighingup to 1,250
pounds;asingledosesyringeof
QUESTtreatshorsesonly up to I,150
pounds;asingledoseof SAFECUARDrreatshorsesup to I,000
pounds.
" Regulardeworming
is a
mustfor effectiveparasileconlrol,"
saidDr KarenHayes.'Thatmeans
estabUshing
a programandstickingto
ir."
Package
instructions
will
specifyhowoftenyou will Deedto
dewom yourhorsefor naximum
effectiveness.
Mostdeworming
productscall for r€application
every
six to eightweeks.
Someproducts
mayciain a
longerduration.
buttakea close
look- you mayfind thattheir
extended
killing powerappliesio only
oneor two parasite
types.QUEST,for
example,
claims84-dayeftectiveness.
bu1tharclaimappliesonly to one
parasite.
Yourhorseis exposed
regularly1()otherparasites
in addilion
1()smallstrongyles
andsbouldbe
dewormedmoreoften to control the
broadest
vectrun of pa]asires.
19
Other Control
Methods
Advancesin scienceand sanitationhavehelpedhorse
ownerscontrol parasileinfestation.Dr. Hayesoffers
thesegeneralrules for keepingthe parasitesunder
>-Whatever dewo.ming method you choose,
use it d;ligently.lf you chooserotational
dewormiDg,be sureto follow the rulesof
thumb detailedon page 16 and administer
the dewomer every six to eight weeks,or
as iDdicatedby laboratoryexam ofyour
horse'smanure.ffyou choosea daily
dewormer. be sure lo add an elTeclive
b o t i c i d ei t ' t r a t e g r cr r m e \ a r l e r ' r r w i . e
per year- to kill bots. lfyou chooseto
dewoffn your horsewitb a broad spectrum
dewormer. mak€ sure the prcduct of choice
t . u l ) j , b r o a d * D e cur m . A d m i r i { e r i r e \ e r y
six to eight weeksor as indicatedt,
laboratoryexam ofyour horse'snanure
(and.again,don'l forget abou! bots).Don l
blindly acceptadverrisingclaims thar
advocatedeworminglessoften, Do matter
what the prod ct is, unlessibere'sproof
thal all ihe parasitcsthatrhreatenyour
horseare elTectivelykilled on that lessstringenlschedule.
>Do not spreadfresh,uncomposted
manureon
grazingpastures.
Compostmanureforat
leasta year.tu.ningit frequentlyto produce
heatneeded
to killthe internalparasire
larvae.Recentstudieshaveshownthal
shredded
newspaper
beddingreaches
highertempemtures
whencomposted
lhan
traditionalstrawor woodshavings,
killing
20
>-Remove
manurefrornyourhorse'sstalldaily.
Someholseownersand veterinarians
recommend
mowingxndchainharowing
to helpexposelarvaeto fie sunandwind,
whichcandry onl thelawaeandkill some
larvae.This rnethodworksbeuerin hoi dry
areas.Beforeyou hanow,contactyour
equineagriculhnalspecialist
and/orlocal
university1odetemineifthis meihodis an
ellbctiveway ro killparasitelarvaein your
>Don't overcrowdpastures.
Expertsadvisea
min;numof oneacreperhorse,moreif
pastures
arethin or soil is poor
>'Rotaiepastur€s
betweencattle,sheepaDd
horses,sinceparasites
aredifferentbetween
:'Wash waterbucketsregularllandreplace
waterdaily.
>Use repellenls
andinsecticides
as
Itts easyto control parasites.
Just remember:
WORK
OBSERVE
REGULAR
MAINTAIN
Regularschedule. Maintain
vigilance.
eatinghabits,
six to eightweeks
SANITATION
Sanitation
methods.
Make
by fecal
Footnotes
L14cdi.ll
rfon
| .o{'.fie.rive
dewo
n ^dE
P?4d
Hup.
Acknowledgements
risheso exrendmanyhedfelilnMks ro
Spinworks
K!€n Hryes.DVM.. andThonasBello,DVM.-Ph.D.,
€quinevelerinria. andpresideni
of Sa.dhillEquine
lor lcndingthct time,trlenr.ard enerCy
to rhis
Cenrer.
pojec! Teny HaqEr or ihe Chdles Duff Adlenhine
Asencyfor hisdesianprcwess:
andChrlstieHeifrenlid
thcpublicilydep.nnentsarFarnanCompanies,
Inc,
providedby
andt(oanimalhoalth.Allparasnephotos
Merial,All Hose photosby DonO CotrnorPhotogtaphy.
21
HorseHealthRecord
Numbers
at a Glance:
Horse:
Notes:
Veterinarian:
Farrier:
Tack & Feed:
Fanier:
Weight:
wdghr:
Farrier:
Weight:
Farrierl
Deworm:
Weight:
Weight:
Weighi:
i
Fanier:
Fanier:
Farrier:
Deworm:
Deworm:
r
Weight:
Weight:
Farier:
Farrier:
Deworml
Deworm:
Weight:
Weighti
t
We;ght:
019SBSpinwo5 Eq! m EdlGtiomlSlr8
.
I
t
,J