Pfizer Parasite Atlas

8/11/2019 Pfizer Parasite Atlas

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PFIZER ATLAS OFVETERINARY CLINICAL

PARASITOLOGY


2/25

Byron L. Blagburn, MS, PhD

College of Veterinary Medicine

Auburn University

Michael W. Dryden, DVM, PhD

College of Veterinary Medicine

Kansas State University

Editors

Animal Health

PFIZER ATLAS OFVETERINARY CLINICAL

PARASITOLOGY

ISBN 0-9678005-3-6


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CONTENTS

Published by The Gloyd Group, Inc.Wilmington, Delaware

Medical illustrations created by Allison Lucas Wright, MS, CMI

and Gene Nunnally Wright, MS, CMI, Athens, Georgia

All photographs courtesy of Byron L. Blagburn, MS, PhD

1999 by Pfizer Inc.All rights reserved. First printing, 2000

Printed in the United States of America.

INTERNAL PARASITES 345 ............Heartworms, Canine

67 ............Heartworms, Feline

89 ............Hookworms

1011............Whipworms

1213 ............Roundworms

1415............DipylidiumTapeworms

1617............Taenia Tapeworms

18 ............Giardia

EXTERNAL PARASITES 192021 ............Fleas

22 ............American Dog Ticks

23 ............Brown Dog Ticks

24 ............Deer Ticks25 ............Common Ticks Compared

26 ............Ear Mites

27 ............DemodexMites

28 ............Cheyletiella Mites

29 ............SarcoptesMites

INTERNAL ORGANS (Canine & Feline) 30-31

UNDER THE MICROSCOPE 333445 ............Photographic aids to identifying common parasites and

pseudoparasites as seen in blood, feces, and urine

The hosts for each parasite are identified at the top of each page

by the following icons representing dog, cat, and/or human hosts.


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INTERNAL PARASITES45 Heartworms, Canine

67 Heartworms, Feline

89 Hookworms

1011 Whipworms

1213 Roundworms

1415 DipylidiumTapeworms

1617 Taenia Tapeworms

18 Giardia


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HEARTWORMSCANINEDirofilaria immitis

4

HEARTWORMSCANINEDirofilaria immitis

INTERNAL

PAR

ASITES

HEARTWORMS

WHIPWORMS

TAPEWORMS

HOOKWORMS

ROUNDWOR

MS

GIARDIA

CANINE HEARTWORM INFECTION

Dog heart infected withadult heartworms

Normal dog heart

A mosquito deposits

heartworm larvaevia saliva puddleinto bloodstream.

A mosquito becomes a heartwormintermediate host by ingesting microfilariae

while biting an infected host.

Adult heartworms live in

the right ventricle andpulmonary artery.**

CANINE HEARTWORM*

Larvae develop intissues and migrate

to the heart wherethey mature to

adult worms.

Length of Life Cycle = Approximately 6 Months

Fertilized adult

female heartwormsrelease microfilariae

into the blood.

* Although rare, humans may develop

pulmonary lesions if infected with D. immitis.

** Adult worm is sometimes found at

ectopic sites, eg, eye, skin, or body cavity.


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6

HEARTWORMSFELINEDirofilaria immitis

INTERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOK

WORMS

ROUNDWORMS

GIARDIA

HEARTWORMSFELINEDirofilaria immitis

Feline heart and lungs infectedwith adult heartworms.**

FELINE HEARTWORM* FELINE HEARTWORM INFECTION

Cat heart and lungsinfected with adult

heartworms

Normal catheart and lungs

Length of Life Cycle = Approximately 8 Months

A mosquito depositsheartworm larvae

via saliva puddleinto bloodstream.

A mosquito becomes a heartwormintermediate host by ingesting microfilariae

while biting an infected host.

Larvae develop intissues and migrate

to the heart wherethey mature to

adult worms

however, many ofthe larvae do notreach maturity in

cats.

Fertilized adult

female heartwormsrelease microfilariae

into the blood.Microfilariae aredifficult to detect

because they are

few in number andare present in bloodfor a short time.

* Although rare, humans may develop

pulmonary lesions if infected with D. immitis.

** Adult worm is sometimes found at ectopic sites, eg,

peripheral arteries, body cavity, or central nervous system.


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8

HOOKWORMSAncylostoma caninum,* Ancylostoma braziliense,* and Ancylostoma tubaeforme*

INTERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOK

WORMS

ROUNDWORMS

GIARDIA

HOOKWORMS

Following ingestion of infectivelarvae in the mothers milk,

puppies begin passing eggs in the

feces in as little as 2 weeks.

Young animals

may be infectedduring nursing

via milk, byingestion ofinfective larvae

in the soil, or byskin penetration.

Eggs hatch and larvaedevelop to infective stage.

Infective larvae are ingested or penetrate the skinand may migrate extensively.

HOOKWORMSAncylostoma caninum, Ancylostoma braziliense, and Ancylostoma tubaeforme

HOOKWORM INFECTION

Small intestine

infected withhookworms

* The life cycles for A. tubaeforme and A. braziliensearesimilar to that shown for A. caninum; A. tubaeforme isgenerally found only in cats; A. caninumand A. brazilienseare found in both dogs and cats; larvae of A. braziliense andA. caninummay cause human cutaneous larva migrans andrarely, eosinophilic enteritis.

Length of Life Cycle = 3 to 4 Weeks

Larvae mature to adult hookworms that

reside in the small intestine, where theycan cause significant blood loss.

Normal smallintestine


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10

WHIPWORMSTrichuris vulpis

INT

ERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOK

WORMS

ROUNDWORMS

GIARDIA

WHIPWORMSTrichuris vulpis

Infective eggs hatch tolarvae and mature to adultworms in 74 to 87 days in

the cecum.

Mature worms

pass eggs inthe feces.

Infective larvae develop in 2

to 4 weeks within the egg.

The dog ingestsinfective eggs

found in soil.

WHIPWORM WHIPWORM INFECTION

Normal cecum

and the ileocecaljunction of the

small andlarge intestine

Infected cecum

with numerouswhipworms

embedded inthe mucosa

Length of Life Cycle = 3 Months


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12

ROUNDWORMSToxocara canis*, Toxocara cati*, and Toxascaris leonina*

INT

ERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOK

WORMS

ROUNDWORMS

GIARDIA

Adult roundworms live

in the small intestine.

ROUNDWORMS

Roundworms maybe transmitted to

young animalsin uteroor via milk

(except T. leonina).

Eggs are passed

in the feces.

Toxascaris

leonina egg

Toxocaracanisegg

Toxocaracatiegg

Infective eggs develop in the environment:

approximately 1 week for Toxascarissp.and 4 weeks for Toxocara sp.

The transport hostsingest infective eggs;larvae encyst in tissues.

The hosts ingest the infective eggs or thetransport host. Larvae of T. canisor T. cati

may migrate extensively within the hosts

ROUNDWORMSToxocara canis, Toxocara cati, and Toxascaris leonina

ROUNDWORM INFECTION

Small intestineinfected with

roundworms

Length of Life Cycle = T. canis, approximately 4 to 5 Weeks; T. cati andT. leonina, =55 Days

Normal small

intestine

* Larvae of both T. canisand T. catimay infect many organ systems in humans

(visceral larva migrans); Toxascaris leonina is of no zoonotic significance.


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TAENIA TAPEWORMSTaenia spp.

16

TAENIA TAPEWORMSTaenia spp.

INT

ERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOK

WORMS

ROUNDWORM

S

GIARDIA

Tapeworm segments

containing infective eggsare passed in the feces.

Occasionally, eggs arepresent in feces.

An intermediate host

ingests the eggs.

The host becomesinfected by eating the

intermediate host

Normal smallintestine

Small

intestineinfected

withtapeworms

The eggs develop tolarvae in the tissues of

the intermediate host.

Adult tapeworms developin the small intestine.

TAENIA TAPEWORM TAENIA TAPEWORM INFECTION


Eggs are released fromthe segments into the

environment.


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18

GIARDIAGiardia spp.

INT

ERNAL

PAR

ASITES

HEART

WORMS

WHIPWORMS

TAPEWORMS

HOOKWORMS

ROUNDWORM

S

GIARDIA

Trophozoites attach to themucosa of the small intestine

and may cause diarrhea.

Trophozoites usuallyform cysts that areintermittently passed

in the feces.

Infective cysts are present in the environment.

Trophozoitesemerge from the

ingested cyst.

GIARDIA

Length of Life Cycle = 1 Week

EXTERNAL PARASITES2021 Fleas

22 American Dog Ticks

23 Brown Dog Ticks

24 Deer Ticks

25 Common Ticks Compared

26 Ear Mites

27 DemodexMites

28 Cheyletiella Mites

29 SarcoptesMitesThe host ingests

cysts from theenvironment,usually from

contaminatedfood or water.

FLEAS FLEAS


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20

FLEASCtenocephalides felis

EXT

ERNAL

PAR

ASITES

FLEAS

TICKS

MITES

FLEA

Adult flea remains on the dog or cat host,feeding and producing eggs.

Eggs fall off of thehost animal and

hatch within 2 to 5days to larvae.

Larvae feed on adult flea

feces which fall off the hostand organic debris present

in the environment.

Larvae developinto pupaeinside a debris-

coated, silk-likefiber cocoon

(cross section).

For each flea on the host, there are hundreds of eggs, larvae, and newly emerged adults,

concentrated in the environment (carpet, bedding, soil, decaying vegetation, etc.).

Adult fleasemerge from

the cocoon insearch of a

blood meal

FLEASCtenocephalides felis

FLEA ALLERGY DERMATITIS

Stage 1Normal skin

Stage 2When a flea bites, it injects a

small amount of saliva into the skin,causing an inflammatory reaction

Stage 4Bacterial infection is a common sequela to

skin trauma caused by scratching.

Stage 3In animals that are allergic to the flea saliva,

the reaction is more pronounced, causing

intense itching. Scratching maycause increased inflammation and hair loss.

Length of Life Cycle = 2 Weeks to Many Months

BROWN DOG TICKSAMERICAN DOG TICKS


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BROWN DOG TICKSRhipicephalus sanguineus

22

AMERICAN DOG TICKSDermacentor variabilis

EXT

ERNAL

PAR

ASITES

FLEAS

TICKS

MITES

AMERICAN DOG TICK

Engorged female ticks

fall off the host and layseveral thousand eggs.

Engorged femalefeeding

Eggs hatch to larvae.

Both larvae

and nymphsfeed on small

mammals.

Adult ticks attach to andfeed on dogs and wildlife

such as raccoons.

Length of Life Cycle = 1 to 2 Years

Larvae feed, anddevelop to nymphs.

Nymphs feed and

develop to adults.



Engorged female

feeding

Eggs hatch to larvae.Larvae and nymphs

feed on dogs andother small mammals.

BROWN DOG TICK

Adult ticks attach toand feed on dogs.

Larvae feed and

develop to nymphs.

Nymphs feed anddevelop to adults.

Length of Life Cycle = 3 Months to 1 Year

DEER TICKS COMMON TICKS COMPARED


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24

DEER TICKSIxodes scapularis (Syn. dammini)

EXT

ERNAL

PAR

ASITES

FLEAS

TICKS

MITES

DEER TICK AMERICAN DOG TICK*



Engorged female

feeding

Larvae feed on mice, the reservoir for

Lyme disease organisms.

Adult ticks attach to

and feed on dogs,white-tailed deer,and other animals.

Length of Life Cycle = 1 to 2 Years

Eggs hatch to larvae.

Larvae feed and

develop to nymphs.

Nymphs feed on mice,

wildlife, dogs, cats, andhumans, and develop to

adults.

BROWN DOG TICK*

DEER TICK*

larva

nymphadult

engorged adult

larvanymph

adult

engorged adult

larvanymph

adult

engorged adult

COMMON TICKS COMPARED

* These ticks are found infrequently on

cats and humans, but they do occur.

DEMODEX MITESEAR MITES


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DEMODEXMITESDemodex canis

DEMODEXMITE

Adult DemodexmiteAll developmental stages

occur on the same host.

Normal canine skin.

Dogs normally have lownumbers of mites.

The entire life cycle of the

Demodexmite occurs on the host.Mites are acquired by puppiesthrough intimate contact with their

infested mother.

Demodexmites live and

reproduce in the hair folliclesand sebaceous glands.

Increased numbers of mites areseen in animals with a genetic

predisposition or disorders ofthe immune system.

Length of Life Cycle = 20 to 35 Days

26

EAR MITESOtodectes cynotis

EXT

ERNAL

PAR

ASITES

FLEAS

TICKS

MITES

EAR MITE

Adult Otodectes cynotismite

Normal feline earanatomy

Ear mites may be found onbody sites other than the ear

canal. Animals becomeinfested by passive contact

with infested animals.

Cat displays effects ofear mite infestation in

the ear canalinflammation, redness,

and swelling of canalstructures.


SARCOPTES MITESCHEYLETIELLA MITES


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SARCOPTESMITESSarcoptes scabiei

SARCOPTESMITE*

Adult Sarcoptes miteAll developmental stages

occur on the same host.

Normal canine skin

Sarcopteslesions often start

on the elbows and earmargins. The disease is

highly contagious to otherdogs, cats, or humans.

Sarcoptesmites tunnelin the skin causing

intense itching.

Length of Life Cycle = 17 to 21 Days

28

CHEYLETIELLA MITESCheyletiella yasguri, Cheyletiella blakei, and Cheyletiella parasitovorax

EXT

ERNAL

PAR

ASITES

FLEAS

TICKS

MITES

CHEYLETIELLA MITES*

Adult Cheyletiella mite

Normal canine skin

Cheyletiella mite infestation

produces hair loss, dullcoat, and dandruff.

Cheyletiella mites live onthe surface of the skin

where they feed andreproduce. The mites arecontagious to other

animals and can survivein the environment.


* Cheyletiella may cause papular eruptions in

humans. They do not reproduce on humans.

* Sarcoptesmay produce severe transient pruritis in

humans but disease is usually self-limiting.

CANINE INTERNAL ORGANS FELINE INTERNAL ORGANS


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30

CANINE INTERNAL ORGANS

CAN

INEINTERNA

LORGANS

FELINE INTERNAL ORGANS

Trachea

Esophagus

Lungs Heart Liver Stomach Pancreas

Kidneys

Small Intestine

Large Intestine

Trachea

Esophagus

Lungs

Heart Liver Stomach Pancreas

Kidneys

SmallIntestine

Large Intestine


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UNDER THE MICRO-34 Dirofilaria immitis

35 Alaria canisAleurostrongylus abstrusus

36 Ancylostoma spp.

37 Eucoleus (Capillaria) aerophilaEucoleus (Capillaria) boehmi

Dipylidium caninum

38 Giardia spp.

39 Isospora canisIsospora ohioensisIsospora felisIsospora rivoltaNeospora caninum

Paragonimus kellicotti

40 Physaloptera spp.Sarcocystisspp.Spirometra mansonoides

41 Strongoloides stercoralisTaenia spp.

42 Toxascaris leoninaToxocara canisToxocara cati

43 Toxoplasma gondiiTrichuris vulpis

44 Pearsonema (Capillaria) feliscatiPearsonema (Cappilaria) plica

45 Pseudoparasites

The egg of Toxocara canisis placed beside each parasite for scale.

Parasites Found in Blood

Parasites Found in Feces

Parasites Found in Urine

Pseudoparasites

PARASITES FOUND IN FECESPARASITES FOUND IN BLOOD


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PARASITES FOUND IN FECES

Aleurostrongylus abstrusus

First-stage larva of Aleurostrongylus abstrusus

Alaria canis

Egg of Alaria canis

Close-up of tail ofA. abstrusus

34

PARASITES FOUND IN BLOOD

UNDERTHEMICR

OSCOPE

Dirofilaria immitis

Adult male heartworm with corkscrew-like tail is in center; adult female is on outside.

Single microfilaria of D. immitis(Difil Filter Test)

Microfilaria of D. immitis(Difil Filter Test)Anterior ends of microfilaria of Dipetalonema

reconditum(left) and D. immitis(Modified KnottTest)


PARASITES FOUND IN FECESPARASITES FOUND IN FECES


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A. caninum

T. vulpis

U. stenocephala

Eucoleus (Capillaria) spp.


Eucoleus (Capillaria) aerophila

Egg of Eucoleus (Capillaria) aerophila(respiratory tract)

Eucoleus (Capillaria) boehmi

Egg of Eucoleus (Capillaria) boehmi(nasopharynx)

Surface of egg

of Eucoleus(Capillaria)boehmi

Dipylidium caninum

Dipylidium caninumegg packet

containing numerous eggs

36


UND

ERTHEMICR

OSCOPE

Ancylostoma spp.

The egg of Ancylostoma caninum The egg of Uncinaria stenocephala

Fecal flotation preparationcontaining eggs of A. caninum,

T. vulpis, U. stenocephala, andEucoleus (Capillaria) spp.

The egg of Ancylostoma braziliense The egg of Ancylostoma tubaeforme

Eggs of A. caninum and T. vulpis

The egg of A. caninum; oocysts ofIsospora canis

The egg of Toxocara canisis placed beside each parasite for scale.The egg of Toxocara canisis placed beside each parasite for scale.



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Neospora caninum

Paragonimus kellicoti

Egg of the lung fluke Paragonimus kellicoti

Isospora canis

Oocysts of Isospora canis (left),I. ohioensis (top), and egg of T.

canis

Isospora felis

Oocysts of Isospora felis Oocysts of Isospora felis(larger) andIsospora rivolta (smaller)

Oocysts ofNeospora caninum(arrows)

Oocysts of

Isospora felis(smaller),and egg ofToxocara cati

38


UND

ERTHEMICR

OSCOPE

Giardia spp.

Cyst of Giardia spp. (Sheathers sucrose

flotation)

Cysts of Giardia spp. (zinc sulfate flotation, iodine stain)

Stained trophozoite ofGiardia spp. (fecal

smear)

Close-up of cysts of Giardia spp. (zinc sulfate flotation, iodine stain)

Isospora felis, Isospora rivolta




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Strongyloides stercoralis

First-stage larvae of Strongyloides stercoralis

Anterior end ofStrongyloidesstercoralis

Taenia spp.

Egg of Taenia spp. Eggs of Echinococcusspp. are

similar, and thus are not easily differentiated fromthose of Taenia spp.

Ruptured egg of Taenia spp.Note the exposed

hexacanth embryo.

40


UND

ERTHEMICR

OSCOPE

Physaloptera spp.

Egg of Physaloptera spp.

Sarcocystis spp.

Sporocytes of Sarcocystis spp.

Spirometra mansonoides

Egg of the tapeworm Spirometra mansonoides




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Toxoplasma gondii

Oocysts of Toxoplasma gondii

42


UND

ERTHEMICR

OSCOPE

Toxascaris leonina

Egg of Toxascaris leonina

Toxocara canis

Eggs of Toxocara canis

Toxocara cati

Egg of Toxocara cati

Surface of egg ofToxocara cati

Eggs ofToxocara canis,Toxascaris leonina,and Ancylostoma

caninum

Trichuris vulpis

Egg of Trichuris vulpis


PSEUDOPARASITESPARASITES FOUND IN URINE


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S U O S S

Soil fungusCommon fecalpseudoparasite

Hair, air bubble, and flea eggfecal pseudoparasites

Egg of rodent tapeworm

appears in feces as result of pre-dation

Mite eggfecal pseudoparasite

Sporocysts of MonocystisorRhyncocystis (earthwormparasites)appears in feces asresult of ingestion

Pine pollenfecal pseudopara-site

Tree pollenfecal pseudopara-site

Plant hairfecal pseudoparasite

Grain mite and air bubble

fecal pseudoparasites

Yeastfecal pseudoparasite

44

S S OUN N U N

UND

ERTHEMICR

OSCOPE

Pearsonema (Capillaria) feliscati

Egg of Pearsonema (Capillaria) feliscati

Egg of Pearsonema (Capillaria) plica


Surface of eggof Pearsonema

(Capillaria)feliscati

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Pfizer Parasite Atlas