Manual de Parasitos Internos

8/9/2019 Manual de Parasitos Internos

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INTERNAL PARASITES OF DOGS AND CATS

DIAGNOSTIC MANUAL

Developed with Dr. Byron BlagburnCollege of Veterinary Medicine

Auburn University


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Parasitology is a fascinating field, especially when exploring the intricate mechanisms by which parasitespropagate. In the fast-paced veterinary clinic environment, the study of parasitology too often becomes routineand mundanewe simply perform yet another fecal examination and dutifully record the results.

I invite you to step out of this routine and rediscover the amazing life cycles of these remarkable organisms.

Challenge yourself to not only identify a hookworm egg by genus alone, but by species. Explore the complexrelationships between parasites and their intermediate and definitive hosts.

This diagnostic manual is designed to be an informative source for the identification and exploration of internalparasites.To be of most benefit to veterinarians and technicians, the manual was designed to be convenient andeasy to use. As youll see,the parasites described in this manual have been divided into two groups accordingto the material (i.e., feces or blood) tested for infection.Additional sections are devoted to pseudoparasites(specimens frequently mistaken for parasites), parasite life cycles and practical, time-saving diagnostic procedures.In addition, you will find guidelines for parasite prevention in dogs and cats developed by the Companion

Animal Parasite Council, plus a handy index.

All of the information provided here is brief and to the point.Wherever possible,symbols are used to convey

key information (see the key at left).

We would like to acknowledge Professor Byron Blagburn,Department of Pathobiology, College of VeterinaryMedicine,Auburn University, for providing astute technical assistance and one-of-a-kind illustrative material forthis manual.

Novartis is pleased to provide you with this laboratory manual to assist with diagnosis of common parasites indogs and cats.We hope it speeds your daily tasks of fecal examination and parasite identification and helps youeducate your clients on risks and prevention of internal parasites.We are honored to work with you toward themost important goal:a happy, healthy pet.

David G. Stansfield, BVSc, MRCVS Jason Drake, DVMDirector, Professional Services Professional ServicesNovartis Animal Health US, Inc. Novartis Animal Health US, Inc.

For inquiries concerning parasite identification or diagnosis, please call our Novartis 24-hour professionalservices number,1-800-637-0281.

INTRODUCTION

SCALE

Throughout this manual, you willfind icons that indicate the speciesaffected by individual parasites (seedefinitions for the species iconsbelow), plus drawings that providerelative size comparisons. In eachkey, a simple drawing of the parasitebeing discussed will be shown nextto a Toxocara spp. egg drawing.

Indicates theparasiteinfects dogs.

Indicates theparasiteinfects cats.

Indicates that oneor more stages inthe life cycle ofthe parasite caninfect humans.


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Parasites found in blood 5Nematodes 6

Parasites found in feces 9Parasites of the gastrointestinal tract

Cestodes 10Nematodes 16Protozoa 22

Parasites of the respiratory tractNematodes 26

Trematodes 27Parasites of the urinary tract

Nematodes 28

Pseudoparasites 29

CONTENTS

Parasite life cycles 35Cestodes 36

Nematodes 39Protozoa 44

Diagnostic techniques 47Direct Smear 48Sedimentation 49Flotation 50

Companion Animal ParasiteCouncil (CAPC) guidelines 55

Index 58


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PARASITES FOUND IN BLOOD

NematodesAcanthocheilonema(Dipetalonema) reconditum 6

Dirofilaria immitis 7

PARASITES FOUND IN BLOOD


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6

Acanthocheilonema(Dipetalonema) reconditum

Note the characteristic smaller size and blunt anteriorend of microfilariae ofA. reconditum (top) and thecharacteristic tapering anterior end of microfilariae of

D.immitis (bottom).

Characteristics of microfilariaeofD. immitisand A. reconditum

Dirofilaria Acanthocheilonemaimmitis reconditum

Length 307322 m 246293 m(310 m average) (280 m average)

Width (13 of length6.17.2 m 4.7 5.8 mfrom anterior end)

Shape of head Tapered Blunted

Cellularity ofCellular Clear spaceanterior end

Condition of tail Straight Button hookshaped in some

(artifact offormalin fixation)

Motility in Stationary Progressivedirect smear of (tends to moveanticoagulated out of fieldwhole blood of view)

PARASITES FOUND IN BLOOD INTERNAL PARASITES OF DOGS AND CATS


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7

AdultD. immitis in the right ventricleof the heart.

Dirofilaria immitis

Microfilariae ofD.immitis as seen on a membrane filtrationtest. Note: Circulating microfilariae are very rarely observed inthe cat.

Dirofilaria immitis


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PARASITES FOUND IN FECES

PARASITES OF THEGASTROINTESTINAL TRACTCestodesDipylidium caninum 10Echinococcus spp. 14Taenia spp. 15

NematodesAncylostoma caninum 16Ancylostoma tubaeforme 17

Uncinaria stenocephala 18Physaloptera spp. 19Toxascaris leonina 20Toxocara canis 20Toxocara cati 20Trichuris vulpis 21

ProtozoaGiardia spp. 22Isospora (Cystoisospora) spp. 23

Toxoplasma gondii 25Cryptosporidium spp. 25

PARASITES OF THERESPIRATORY TRACTNematodesAelurostrongylus abstrusus 26Eucoleus (Capillaria) aerophilus 26

TrematodesParagonimus kellicotti 27

PARASITES OF

THE URINARY TRACTNematodesPearsonema (Capillaria) feliscati 28Pearsonema (Capillaria) plica 28



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10

PARASITES FOUND IN FECES INTERNAL PARASITES OF DOGS AND CATS

Egg packet ofD.caninum

Dipylidium caninum

PARASITES OF THE GASTROINTESTINAL TRACT CESTODES

Comparison of adultD.caninumwith a canine roundworm.

Dipylidium caninum

SCAL

E


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Dipylidium caninum

Parasites of the GASTROINTESTINAL TRACT CESTODES

DriedD.caninum segments; sometimes found by pet owners.

Dipylidium caninum

AdultD.caninum. Note that the segments arelonger than they are wide.Dried proglottids(segments) are sometimes brought in foridentification by pet owners.


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Dipylidium caninum Taenia pisiformis*

INTERNAL PARASITES OF DOGS AND CATSPARASITES FOUND IN FECES

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Comparison of common tapeworms in dogs and cats

*A similar tapeworm, Taenia (syn. Hydatigera) taeniaeformis infects cats. It resembles T. pisiformis.

Both Dipylidium and Taenia tapeworms are generally nonpathogenic to dogs or cats. Rarely, heavy

infections can cause soft or diarrheic feces, restlessness, abdominal pain, dull coat, and excessivegrooming of the perineum due to pruritus. Dipylidium caninum can infect humans, particularly smallchildren, resulting in similar clinical signs.

Disease potential indogs or cats

NoYes, usually small childrenZoonotic potential

Individual eggs consist of a hexacanth embryowithin a radially striated embryophore. Eggs(3040 m) are usually passed individually in feces.Eggs ofT. pisiformis cannot be distinguished fromeggs of other Taenia spp., or from those ofEchinococcus spp.

Individual eggs consist of a hexacanth (6-hooked)embryo within a thin embryophore (shell); individualeggs are contained in packets of 330 eggs. Eggpackets (200300 m) are passed in feces or retainedwithin proglottids.

Structure of eggs

Mature proglottids are square to rectangular, witha single set of reproductive organs opening into

alternating unilateral pores. Gravid proglottidstend to be rectangular and more elongated.

Oblong (resemble cucumber seed), with two sets ofreproductive organs opening into bilateral pores;

proglottids are often motile. Dried proglottidsresemble rice grains.

Structure of mature/gravid proglottids(tapeworm segments)

Large rostellum with a double row of large hooks;rostellum is surrounded by 4 suckers

Small rostellum (attachment device) armed with manysmall hooks; rostellum is surrounded by 4 suckers

Structure of head

Large; 0.62 meters (1.96.6 feet)Small; 0.2 0.8 meters (0.6 2.6 feet)Size

RabbitsFleas, liceIntermediate host

DogDog, cat, rarely humansDefinitive host

Dog - Rabbit tapewormCucumber seed tapewormCommon name


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Selected tapeworms of veterinary importance

*All tapeworms inhabit the small intestine of the definitive host.

Tapeworm Species Definitive Hosts* Intermediate Hosts Larval Stage; Site of Larval Tapeworm Development

Dipylidium caninum Canids, felids, Flea, louse Cysticercoid; body cavity of insectsrarely humans

Taenia pisiformis Canids Rabbits Cysticercus; abdominal cavity and liver of rabbits

Taenia hydatigena Canids Livestock Cysticercus; abdominal cavity and liver of livestockTaenia ovis Canids Sheep, goats Cysticercus; musculature of intermediate hosts

Taenia multiceps Canids Sheep, cattle, humans Coenurus; brain and spinal cord of intermediate hosts

Taenia serialis Canids Rabbits, rodents, Coenurus; connective tissue of rabbits,rarely humans rodents and rarely humans

Taenia taeniaeformis Felids Rodents Strobilocercus; liver of rodents

Mesocestoides spp. Canids, felids Coprophilic insect Tetrathyridium in insect or mite and inor mite (1st host); abdominal cavity and liver of vertebratesmammals, reptiles,frogs, birds (2nd host)

Echinococcus granulosus Canids Livestock, humans Unilocular hydatid cyst; liver, lungs

Echinococcus multilocularis Canids, rarely felids Rodents, humans, Multilocular hydatid; liver, lungsrarely pig, horse

Spirometra mansonoides Felids, canids, Copepods (1st host); Procercoid (body cavity of copepods); plerocercoidraccoons many verterbrates (body musculature and subcutaneous fascia of

except fish (2nd hosts) vertebrates)

Diphyllobothrium latum Humans, canids, Copepods (1st host); Procercoid (body cavity of copepods); plerocercoidfelids, porcids fish (2nd host); several (abdominal cavity, musculature of fish)

paratenic hosts


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Eggs ofE. granulosus

Echinococcusspp.

AdultE. granulosus.AlthoughE. granulosusoccurs only in thedog,other species of

Echinococcus appearin dogs and cats.

Parasites of the GASTROINTESTINAL TRACT CESTODESS

CALE


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Eggs ofT.pisiformisNote: Cats are host tootherTaenia spp.

Adult T.pisiformis.Note the difference insegment shape comparedto adultD.caninum.

Taenia spp.

Parasites of the GASTROINTESTINAL TRACT CESTODESS

CALE


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Egg ofA. caninum

Ancylostoma caninum Ancylostoma caninum

Anterior end of adultA. caninum.Note the three pairs of ventral teeth.

Parasites of the GASTROINTESTINAL TRACT NEMATODESS

CALE


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Egg ofA. tubaeforme

Ancylostoma tubaeforme


CALE

PARASITES FOUND IN C S


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Egg ofU.stenocephala

Uncinaria stenocephala Uncinaria stenocephala

Note the differences in size between U.stenocephala (upperright) and A. caninum (lower left).


CALE


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Physaloptera spp.

Embryonated eggs ofPhysaloptera spp.(stomach worm)


CALE

S S S C SPARASITES FOUND IN FECES


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Egg ofT.leonina

Toxascaris leonina Toxocara canis

Egg ofT. canis

Toxocara cati

Egg ofT.catiNote the size is about10 percent smallerthan the T.canis egg.

Parasites of the GASTROINTESTINAL TRACT NEMATODES1 2 3S

CALE

1: T. canis

2: T. leonina

3: T. cati


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Egg ofT.vulpis

SCALE

Trichuris vulpis Trichuris vulpis

Adults ofT.vulpis Note how the lash-like anterior endsare laced through the mucosa.

Parasites of the GASTROINTESTINAL TRACT NEMATODES



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Motile trophozoite ofGiardia spp.(iodine stain)

Giardia spp. Giardia spp.

Cyst ofGiardia spp. (iodine stain)

Parasites of the GASTROINTESTINAL TRACT PROTOZOAS

CALE

1 2

1: trophozoite

2: cyst


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Nonsporulated oocysts ofI. canis Nonsporulated oocysts ofI. ohioensis

Isospora (Cystoisospora)spp.

Parasites of the GASTROINTESTINAL TRACT PROTOZOA21S

CALE

1: I. canis

2: I. ohioensis



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Parasites of the GASTROINTESTINAL TRACT PROTOZOA

Isospora (Cystoisospora)spp.

Nonsporulated oocysts ofI. felis Nonsporulated oocystsofI. rivolta

21SCALE

1: I. felis

2: I. rivolta


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Nonsporulated oocysts ofT.gondiiCompare the size ofT.gondiitoI. felis inthe background.

21SCALE

Toxoplasma gondii

Parasites of the GASTROINTESTINAL TRACT PROTOZOA

Cryptosporidium spp.

Sporulated oocysts ofCryptosporidium spp.

1: T. gondii

2: Cryptosporidium spp.



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Larva ofA.abstrususNote dorsal appendage on tail of larva.

Aelurostrongylus abstrusus

Parasites of the RESPIRATORY TRACT NEMATODES

Egg ofE.aerophila

Eucoleus (Capillaria) aerophilus

SCALE

1 2

1: A. abstrusus

2: E. aerophilus


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Egg ofP. kellicotti. Note the collar surroundingthe operculum.

Paragonimus kellicotti

Parasites of the RESPIRATORY TRACT TREMATODESSCALE



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Egg of aP. plica from urinary sedimentation

Pearsonema (Capillaria) plica

Stained egg ofP. feliscatifrom urinary sedimentation

Pearsonema (Capillaria) feliscati

Parasites of the URINARY TRACT NEMATODES21S

CALE

1: P. feliscati

2: P. plica


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PSEUDOPARASITES

PseudoparasitesAlternaria spp. 30Free-living nematode 31Grain mite egg 32Planarian 32Pollen granules 33

Spurious parasiteMonocystis lumbricior

Rhyncocystis pilosa spore 34

Pseudoparasites are specimens found in feces or blood that are mistaken for parasites.(For the purpose of this manual, only examples of pseudoparasites found in fecesare included.) Pseudoparasites can be differentiated from spurious parasites,which areparasites of a host other than the host under examination.For example,dogs andcats often consume feces of other vertebrate animals or consume invertebrates and willsometimes excrete stages of parasites unique to their prey.Monocystis lumbriciis anexample of a spurious parasite.While it is a true parasite of earthworms, dogs and catscan ingest earthworms, causingM. lumbricito appear in fecal examinations.

PSEUDOPARASITES


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These conidia are common environmental fungal contaminants.

PSEUDOPARASITES INTERNAL PARASITES OF DOGS AND CATS

Alternaria spp.

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These pseudoparasites are often recovered from feces collected from the ground.Note the bulbed esophagus.

Free-living nematode

INTERNAL PARASITES OF DOGS AND CATSPSEUDOPARASITES


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32

Dogs and cats ingest these eggs by eating mite-infested food.Eggs are often recovered during fecal flotation.

Grain mite egg

This free-living flatworm is not a parasite but crawls into waterdishes kept outside. It can then be ingested and issometimes regurgitated by dogs and cats.

Planarian


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33

Pine pollen

Pollen granules Pollen granules

Tree pollen

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These spurious parasites often infect earthworms;dogsand cats may ingest earthworms. In fecal flotations, thespore is similar in appearance to eggs ofT.vulpis, although

much smaller.

Monocystis lumbriciorRhyncocystis pilosa spores


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PARASITE LIFE CYCLES

Cestodes

Dipylidium caninum 36Echinococcus spp. 37Taenia spp. 38

Nematodes

Aelurostrongylus abstrusus 39Ancylostoma spp. 40

Uncinaria stenocephala 40Dirofilaria immitis 41Toxascaris leonina 42Toxocara canis 42Toxocara cati 42Trichuris vulpis 43

Protozoa

Isospora (Cystoisospora) spp. 44Giardia spp. 45

Toxoplasma gondii 46

PARASITE LIFE CYCLES


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Posterior (gravid) segments

or individual egg packetsare passed in feces

Adult worms in small intestine

Eggs ingested

by larval flea*

*On occasion, the dog louse, Trichodectes canis,serves as an intermediate host forDipylidium caninum.

Segments and egg packets infeces and on fur in perineal area

Larval flea

develops

into adult flea

Infected adult

flea ingestedby dog or cat

Tapeworm eggdevelops into infective

tapeworm larval stage

by the time the adult flea develops

DIPYLIDIUM CANINUM

Prepatent period: 1421 days

INTERNAL PARASITES OF DOGS AND CATSPARASITE LIFE CYCLES

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Eggs in feces

Posterior segments

of adult wormspass in feces

Eggs are releasedfrom segments

Adult worms insmall intestine

Eggs ingested byintermediate host

Tissues of intermediate

host ingested bydog or cat


ECHINOCOCCUSspp.

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Adult worms insmall intestine

Posterior segments ofadult worms or eggs

are passed in feces

Tissues ofintermediatehost ingestedby dog or cat

Eggs ingested byintermediate host (mouse,

rabbit, squirrel, etc.)


Eggs releasedfrom segments orare free in feces

TAENIA spp.

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Larvae moveto intestine

via tracheal

migration

Adult worms inlung produce eggs;larvae hatchfrom eggs

Larvae arepassed in feces

Tissues of transport

hosts ingestedby cat

Tissues ofintermediatehost ingestedby cat

Transporthost ingestsintermediate host

AELUROSTRONGYLUS

ABSTRUSUS

Larvae ingested by intermediate

hosts (snails and slugs)


ONLY

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Nonembryonated eggspass in feces

Adult worms lay eggsin small intestine

Larvae migrate via lungsor directly to the intestineand mature to adult


Infective larvaepenetrate skin

Infected larvaeingested bydog or cat

Transmission routes to offspring*

Eggs embryonate and hatch;larvae undergo two moltsto infective third-stage larvae

ANCYLOSTOMA spp.

UNCINARIA STENOCEPHALA

*Ancylostoma spp.: Transmammaryroute is the principal route oftransmission. Transplacental transmissionoccurs rarely, if at all.

Uncinaria spp.: Apparently these parasites arenot transmitted by either transplacental ortransmammory routes.

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Note: A. caninum

can infect humans

A.caninum produces about20,000 eggs per day


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Note: Infective larvae reach theheart and lungs about 3 monthsafter being transmitted to theanimal by a bite from a carriermosquito. A positive bloodtest will be achieved after66.5 months, when infectivelarvae have matured intoadult heartworms.

DIROFILARIA IMMITIS


Mosquito ingests microfilariaewith blood meal

Larvae mature into adults in heart; femaleadult worms release microfilariae in blood

Mosquitobites dog or catand transmitsinfective larvae

Microfilariae develop inmosquito to infective larvae.Development in the mosquito istemperature-dependent; infective

larvae can develop in 8 days at 30C

Effects of immature heartworms:

Disease associated withDirofilaria immitis maynot be limited to mature adult worms.Immatureheartworms (L5 stages) generally arrive in theheart between 70 and 100 days.These small worms

(approx.1.5 cm) are carried by the f low of bloodto the distal pulmonary arteries. Inflammatoryevents associated with these and maturing laterstages include peri-arteritis,interstitial edema andinflammatory interstitial disease.These immatureworms in the pulmonary vessels are notdetectable by veterinarians with availableheartworm tests.

Effects of adult heartworms:

Presence of adult worms in the rightheart and pulmonary arteries results inthe more commonly observed diseasesyndrome.The physical presence ofadult worms can lead to inflammation

and proliferation of the arterial walls(villous endarteritis). Death of adultworms and resulting embolic wormfragments can trigger a cascade ofinflammatory events leading tothrombosis and decreased bloodflow to the lungs. In severe,longstanding infections,ventricularhypertrophy and classical rightheart failure are observed.



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Nonembryonated eggspass in feces

Adult worms lay eggs insmall intestine

Prepatent periods:T. leonina: 74 daysT. canis: 2835 daysT. cati: 21 days

Embryonatedeggs ingestedby dog or cat

Embryonated eggs ingestedby intermediate host

Tissues ofintermediatehost ingestedby dog or cat

Transmission routesto offspring*

*T. canis: Transplacental or transmammary T. cati: Transmammary

Embryonated eggs survive for longperiods in contaminated environments

Eggs embryonate

TOXASCARIS LEONINA

TOXOCARA CANIS

TOXOCARA CATI

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Adult T.canis produce25,00085,000 nonembryonatedeggs per day.

Adult T.catiproduce19,00024,000 eggs per day.

Note:Toxocara spp.can infect humans.


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ONLY

Eggs are passedin feces; eggs may beshed intermittently

Adult worms lay eggs incecum or large intestine

Embryonatedeggs in feces

Embryonatedeggs ingestedby dog

Prepatent period: 1112 weeks

Embryonatedeggs can survive

for years inthe environment

Eggs embryonate

TRICHURIS VULPIS

43

Each female T.vulpis produces anaverage of 2,035 eggs per day.



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Asexual and sexual stagesdevelop in intestines

Nonsporulated oocystspassed in feces

Tissues ofintermediatehosts ingestedby cat or dog

Sporulatedoocysts

ingestedby cator dog

Sporulated oocystsingested byintermediate host

ISOSPORA (CYSTOISOSPORA)spp.

Oocysts sporulatein environment


44


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Infective cysts are

passed in feces

Trophozoites develop toinfective cyst stage as they passto the large intestine

Cysts ingestedby dog or cat

Cysts are presentin contaminatedenvironments,including food,

water and fomites


GIARDIA spp.

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Development of the parasite

in the intestine of the cat leadsto development of oocysts

Nonsporulated oocystspassed in feces

Tissues ofintermediatehosts ingestedby cat

Sporulatedoocystsingestedby cat

Sporulated oocystsingested by many potentialintermediate hosts

Human exposure through catfeces or consumption of rawor undercooked meat

TOXOPLASMA GONDII

Oocysts sporulatein environment


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DIAGNOSTIC TECHNIQUES

Direct Smear 48Sedimentation 49Flotation 50

Do not underestimate the importance of accurately conducting fecal examinations.Internal parasites that can be detected by fecal examination remain prevalent in U.S.dogs and cats; some of these are important zoonotic agents.

The following descriptions will help choose the most appropriate diagnostic procedure.You will also find guidelines and techniques to help achieve the greatest success whileconducting these procedures.

DIAGNOSTIC TECHNIQUES

G C


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DIAGNOSTIC TECHNIQUES INTERNAL PARASITES OF DOGS AND CATS

48

The direct smear technique is most appropriate when:

You suspect protozoa that can be demonstrated as active motile stages

(e.g.,Giardia or trichomonads). You suspect a parasite that passes motile larval stages in feces.

Flotation solution might distort the parasite stages you wish to detect.

Notes:

Many larvae also can be recovered in a flotation procedure.

The direct smear procedure is convenient and fast, but has low

sensitivity due to the small amount of feces used and the amount of

debris on the slide.

Direct smear procedure:

1. Apply a small amount of fresh feces to water or saline solution on

a slide and mix thoroughly.

2. Add a coverslip.

3. Examine the entire slide.Thickness of the smear should allow

reading newsprint placed beneath it.

Note:

Iodine can be added to the direct smear at the coverslip margin to

stain motile protozoa, cysts or larvae or for flotation techniques,

the coverslip can be added to a drop of iodine already placed on

the slide.

Direct Smear


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49

The sedimentation procedure is most appropriate when:

Parasite stages are too heavy to float in standard flotation solutions

(e.g.,heavy operculated fluke eggs or larvae of lungworms).

Flotation solutions may distort the parasite stages you wish to detect.

Notes:

Centrifuging sedimentation samples can increase test speed and

improve performance.

Some larvae can be recovered in a flotation procedure.

A sedimentation preparation can be difficult to read due to largeamounts of debris on the slide.

Sedimentation procedure:

1. Centrifuge or let preparation stand until sediment forms.2. Remove most of the liquid above the sediment.

3. Place a drop of the sediment on a slide, then add a cover-slip and examine.

Sedimentation

Sample preparation forsedimentation

Simple straining procedures canseparate large debris from para-sites and from smaller debris.

1. Mix feces thoroughlywith water in a cleandisposable cup.

2. Pour the mixture throughgauze sponges or a strainerinto a second clean cup.

3. Add the strained mixture toa tube.

INTERNAL PARASITES OF DOGS AND CATSDIAGNOSTIC TECHNIQUES


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50

Simple flotation is most appropriate when:

You want better sensitivity than can be provided in a direct smear.

A centrifuge is not available or feasible.

Notes:

Simple flotation improves sensitivity over direct smear when a smallamount of feces is being tested.

Simple flotation provides less sensitivity than flotation using centrifugation.

Simple flotation procedure:1. Mix feces and flotation solution (see sidebar at left) and pour into

a tube.

2. Add flotation solution to form a meniscus.3. Add coverslip and wait 15 minutes.

4. Remove coverslip,place on slide and examine.

Simple flotation

Flotation solutionguidelines

Desired specific gravity ofa fecal flotation solution is1.181.20, measured with ahydrometer.

Common parasite eggs havespecific gravities between1.06 and 1.20.

Remember that simpleflotation may underestimateor misdiagnose low parasite

burdens.

Sample preparationfor flotationSimple straining procedures canseparate large debris from para-sites and from smaller debris.

1. Mix feces thoroughly withflotation solution in a cleandisposable cup. Try to use atleast 1 gram of fresh feces.

2. Pour the mixture through

gauze sponges or a strainerinto a second clean cup.



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Flotation solutionguidelines

Desired specific gravity of a fecalflotation solution is 1.181.20,

measured with a hydrometer. Common parasite eggs havespecific gravities between1.06 and 1.20.

Sample preparationfor flotationSimple straining procedures canseparate large debris from para-sites and from smaller debris.

1. Mix feces thoroughly withflotation solution in a clean dis-posable cup. Try to use at least

1 gram of fresh feces (a cubeabout 12 inch on each side).

2. Pour the mixture throughgauze sponges or a strainerinto a second clean cup.


Centrifugal flotation is most appropriate when:

Sensitivity is the most important criteria in selecting a fecal examination procedure.

Notes:

Increased test sensitivity will improve accuracy in recovering fecal stages from

animals with low parasite burdens.

Centrifugal flotation is the most sensitive fecal concentration procedure available to

the veterinarian.

Centrifugal flotation procedure with a swinging bucket centrifuge:

1. Mix feces and flotation solution (see sidebar at left) and pour into acentrifuge tube.

2. Place sample in centrifuge tube holder.3.Add f lotation solution to form a meniscus and place a coverslip on the tube.

4 Spin at 1,200 rpm for 10 minutes.

5 Stop centrifuge, remove coverslip,place on slide and examine.

Centrifugal flotation procedure with a fixed-angle centrifuge:

1. Mix feces and flotation solution (see sidebar at left) and pour into acentrifuge tube, filling to within 1/2 to 1 inch of the top.

2. Place sample in centrifuge tube holder.

3. Spin at 1,200 rpm for 5 minutes.4. Stop centrifuge, place sample upright in a tube holder and add flotation

solution to form a meniscus.5.Add a coverslip and let stand for 10 minutes.

6. Remove coverslip,place on slide and examine.

Centrifugal flotation

INTERNAL PARASITES OF DOGS AND CATSDIAGNOSTIC TECHNIQUES


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Common fecal flotation solutions

PreparationFlotation Specific (hot water) Comments

Water 1.00 (standard Not applicable Not applicablefor comparison)

Sodium chloride 1.20 approx. 400 g/liter Inexpensive;forms crystals on slide.

Sodium nitrate 1.181.20 approx. 400 g/liter Good all-purpose solution;forms crystals on slide.

Zinc sulfate 1.181.20 approx. 371 g/liter Good all-purpose solution; excellent for protozoa.Best general-purpose specific gravity = 1.181.20;forms crystals on slide.

1.29 approx. 700 g/liter Will levitate heavy debris and parasites.Forms crystals more rapidly.

Magnesium sulfate 1.27 approx. 500 g/liter Good all-purpose solution.Will levitate heavy debris and parasites.

Sheathers sucrose 1.27 approx. 1,278 g/liter Excellent all-purpose solution; Add 6 ml phenol orformaldehyde to inhibit microbial growth; sticky solutionattracts flies and other pests; this viscosity requireslonger incubation time in simple flotation. Does notcrystallize or distort specimens if samples are held.


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Specific gravities of selectedparasites of companion animals*

*Modified from Payne PA and Dryden MW. DVM Best Practices, March 2003, pp. 811.

Parasite Common Name Specific Gravity

Ancylostoma spp. hookworm 1.06

Physaloptera spp. stomach worm 1.24

Taenia spp. taeniid tapeworm 1.23

Toxocara canis canine roundworm 1.09

Toxocara cati feline roundworm 1.10

Trichuris vulpis canine whipworm 1.15


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CAPC GUIDELINES

The Companion Animal Parasite Council (CAPC) is an independent council of U.S.veterinary,governmental and association thought leaders brought together to createguidelines for optimal control of internal and external parasites that threaten thehealth of pets and people. For more information on CAPC,go to www.capcvet.org.

CAPC GUIDELINES

CAPC GUIDELINES INTERNAL PARASITES OF DOGS AND CATS


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CAPC GUIDELINES INTERNAL PARASITES OF DOGS AND CATS

Administer year-round treatment with broad-

spectrum heartworm anthelmintics that have

activity against parasites with zoonotic potential.

Administer preventive flea and/or tick products as

soon after birth as possible (consistent with label

claims) for the life of the pet.

Conduct annual physical examination with completehistory.

Conduct periodic (annual is ideal) heartworm infectiontesting in dogs and periodic testing in cats.

Feed pets cooked or prepared food (not raw meat) and

provide fresh,potable water.

Conduct fecal examinations two to four times during

the first year of life and one to two times per year inadults,depending on patient health and lifestyle factors.

Administer anthelmintic treatment of puppies at 2, 4, 6and 8 weeks of age, followed by administration of a

monthly preventive.

Administer biweekly anthelmintic treatment of kittensbetween 3 and 9 weeks of age, followed by administra-

tion of a monthly preventive.

Treat nursing bitches and queens along with their off-

spring.

Tailor parasite prevention programs to geographic, sea-

sonal and lifestyle factors.

GUIDELINES FOR CONTROLLING PARASITES IN DOGS AND CATS

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In the absence of optimal year-round

heartworm preventive/intestinal parasite

combination products, use the following protocol:

Deworm puppies and kittens at 2, 4, 6 and 8 weeks of

age and then again monthly until 6 months of age.

In kittens,begin biweekly anthelmintic treatment

between 3 and 9 weeks of age and then treat monthlyuntil 6 months of age.

Conduct fecal examinations two to four times a year inadult pets,depending on patient health and lifestyle

factors,and treat with appropriate parasiticides.

Test for heartworm status yearly in dogs and/or beforestarting preventive medications.

INTERNAL PARASITES OF DOGS AND CATSINDEX


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LifeParasites Identification Cycles

Acanthocheilonema (Dipetalonema) reconditum 6

Aelurostrongylus abstrusus 26 39

Ancylostoma caninum 16 40Ancylostoma tubaeforme 17 40

Cryptosporidium spp. 25

Dipylidium caninum 10 36

Dirofilaria immitis 7 41

Echinococcus spp. 14 37

Eucoleus (Capillaria) aerophila 26

Giardia spp. 22 45

Isospora (Cystoisospora) spp. 23 44

Paragonimus kellicotti 27

Pearsonema (Capillaria) feliscati 28Pearsonema (Capillaria) plica 28

Physaloptera spp. 19

Taenia spp. 15 38

Toxascaris leonina 20 42

Toxocara canis 20 42

Toxocara cati 20 42

Toxoplasma gondii 25 46

Trichuris vulpis 21 43

Uncinaria stenocephala 18 40

Pseudoparasites Identification

Alternaria spp. 30

Free-living nematode 31

Grain mite egg 32Planarium 32

Pollen granules 33

Spurious Parasite Identification

Monocystis lumbricior

Rhynococystis pilosa spore 34

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INSIDE BACK COVER


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2004 Novartis Animal Health US, Inc. COR 030022B

Manual de Parasitos Internos

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