Helminth Parasites Grouped by Location in Host

Select Location to Visit

Esophagus   Stomach  

Small intestines   Large intestines

Body cavity   Liver   Kidney and bladder  

Heart and vasculature   Lungs

   Sensory    Brain and spinal cord   

Skin and connective tissues   Muscles

Upper Gastrointestinal Tract

Esophagus

• Spirocerca lupi:
  • Eggs [1]  [2]  [3]  
  • Diagram [Adult]
  • Lesions [Esophagus] [Aorta] [Aorta and esophagus] 
  • Associated lesions [Osteosarcoma] [Pulmonary hypertrophic osteoarthropathy]
• Gongylonema spp:
  • Adults [Showing cuticular plaques]  
  • Lesion [Ruminant esophagus]

Stomach, Rumen or Abomasum

• Habronema sp: (Draschia similar)
  • Typical lesion [Horse stomach]
• Physaloptera spp:
  • Eggs [1]  [2]  [3]  [4]  
  • Adults  [Head]  [Male] [Male tail]  [Female]
  • Morphology [Diagram of head]  
  • Lesion [Stomach of dog]
• Paramphistomum:
  • Egg [1]   
  • Adult [Stained fluke]
  • Lesion [Cyst in trachea]
• Ollulanus tricuspis  
  • Adults [Adult male]  [Adult female]  
  • Diagram [Adult features]
• Ascarops (right) and Physocephalus (left) [Diagram of cephalic and oral structures]
• Gnathostoma  [Diagram of head]

PGE Complex (trichostrongyle species found in the abomasum and small intestines of domestic ruminants)

Trichostrongyloidea

• Typical eggs [1]  [2]  [3] 
• Trichostrongyle size comparison  [Trichostrongylus, Ostertagia, Haemonchus]
• Ostertagia ostertagi  [Male bursa on left] [Cervicle papilliae] [Abomasal lesions] [Lesions]
• Haemonchus contortus  [Male bursa on right] [Bursa] [Spicules] [Cervicle papilliae]  [Bottlejaw]
• Hyostrongylus rubidis (in swine stomach; comparable to Haemonchus)
• Marshallagia marshalli (abomasum of ruminants comparable to Haemonchus)
• Trichostrongylus axei  [Male spicules]  [Size; top pair of worms]
• Trichostrongylus (other species in small intestines)
• Cooperia [Cuticular striations]
• Nematodirus spp
  • male [Male head and tail]  [Bursa with fused spicule]   [Fused tip of spicules]
  • female [Egg on right]  [Egg]  [Cephalic inflation]  [Female tail spine] 

Small Intestines

Ancylostomatoidea (Hookworms)

• Ancylostoma [Bursate tail]  [Bursate tail] [Buccal capsule]  [Scanning EM]  [Ventral teeth diagram]
• Ancylostoma  [Buccal capsule with ventral teeth]  [Adult male and female Ancylostoma]
• Ancylostoma  [Lesions in small intestines]  [Cutaneous larval migrans (CLM)]  [Histopath]
• Uncinaria spp and Bunostomum spp [Buccal capsule with ventral cutting plates]  [Drawing of head]
• Hookworm eggs   [Typical egg]  [Egg]
• Globocephalus (pig hookworm with ventral cutting plates similar to Uncinaria)
• Necator americanus [Head of human hookworm]

Ascaridoidea (Ascarids)

• Ascarid morphologic features   [Adult male and female]  [Lip diagram]  [Ascarid lips]
• Toxocara canis eggs (Baylisascaris and T. vitulorum are similar) [Typical egg]  [Larvated egg]
• Toxocara canis  [Identifying features]  [Adult ascarids in intestines]  [Lung lesions] 
• Toxascaris leonina [Typical Egg]   [Egg]   [Eggs:Toxocara, top; Toxascaris, bottom]       [Adults in cat bile duct] 
• Parascaris equorum  [Typical egg]  [Egg]  [Adult ascarids in horse intestines]
• Ascaris suum [Egg]  [Egg]  [Liver with milk spots]  [Liver with milk spots]
• Ascaridia (Ascarid of poultry and other birds)

Rhabditoidea

• Strongyloides (papillosus, ransomi, westeri) [Typical larvated egg]  [Egg]  [Egg]             [Adults: small intestine histopath]
• Strongyloides (canis, stercoralis, tumefaciens) [Infective L3]  [Infective L3]
• Strongyloides morphology [Diagram of stages]  [Strongyloides L3 and Ancylostoma L3 compared]

Trichinelloidea

• Capillaria bovis [Typical egg] [Stichosome with stichocytes]
• Trichinella spiralis [Drawing of adult male and female] [Female] [Female] [Male] [Tail of male] [Larva]
• Eggs size  [Ancylostoma, Trichuris and Capillaria compared]

Cestodes (Order Cyclophyllidea)

Taeniidae:

• Eggs   [Taeniid Egg] [Eggs] [Eggs]
• Metacestodes  [Cysticercus] [Cysticercus] [Cysticerci in muscle] [Cysticerci in viscera]
• Taenia spp  [Adult morphology] [Scolex] [Circle of hooks] [Scolices] [Strobila] [Mature proglottids]
• Taeniiasis [Adult taeniids in small intestines of a dog] [Adults in gut]
• Echinococcus granulosus [Adult worm] [Hydatid cyst] [Hydatid cyst section] [Protoscolices]

Anoplocephalidae:

• Eggs  [Egg] [Egg]
• Metacestodes   [Cysticercoid]
• Adults   [Typical scolex]  [Moniezia adult from cattle or sheep]  [Anoplocephala in horse gut]

Mesocestoididae [Egg] [Scolex] [Mature proglottids of Mesocestoides with paruterine organ] [Adult drawing]

Dilepididae

• Dipylidium caninum [Egg packets] [Egg packets]
• Dipylidium caninum [Scolex]  [Mature proglottids] [Gravid dried proglottid from bed sheets]

Hymenolepididae [Hymenolepis diminuta egg] [Scolex] [Hymenolepis nana in mouse gut]

Cestodes (Order Pseudophyllidea)

• Diphyllobothrium latum [Egg] [Scolex] [Mature proglottids]
• Spirometra mansonoides [Egg] [1st Intermediate host]

Trematodes

• Fluke egg [Typical egg with operculum]  [Typical egg] 
• Nanophyetidae [Nanophyetes salmincola adult] [Adult fluke] [Metacercariae in fish]
• Opisthorchidae [Opisthorchis species similar to Amphimeris pseudofelineus in cats]
• Echinostomidae [Echinostoma adult]
• Diplostomatidae [Alaria adult] [Strigea adult]

Acanthocephalans

• Eggs [Egg] [Egg] [Egg] [Egg] [Egg]
• Head or proboscis [Thorny proboscis] [Thorny proboscis]
• Lesions [Adult worms attached to small intestine]
• One of many found in can of tuna fish [Adult worm found in can of tuna fish]

Large intestines

Strongyloidea

• Strongyle characteristics [Egg] [Eggs] [Eggs] [Eggs] [Bursate tail]
• Strongylus vulgaris [Buccal capsule] [Anterior mesenteric artery] [Intestinal infarct] [Adult male]
• Horse small strongyles [Assorted adults] [Buccal capsule] [Buccal capsule] [Buccal capsule]
• Oesophagostomum [Buccal capsule] [Buccal capsule] [Buccal capsule] [Nodular lesion]
• Chabertia ovina [Adult]

Trichuroidea

• Trichuris (whipworms) [Adult diagram]  [Egg] [Egg] [Egg] [Adults] [Adults in large intestines]
• Trichuris trichiura in humans:  [Rectal prolapse in human child]

Oxyuroidea (pinworms)

• Oxyuris equi [Egg]
• Typical pinworm morphology   [Pinworm diagram] [Adult female] [Adult females]
• Turtle pinworm  [Adult female]

Body Cavities and Viscera

Body cavity

• Setaria equina [Adult with immature Strongylus edentatus found in peritoneal cavity of a zebra]
• Strongylus edentatus (migrating immature worms) [Immature L5 found with Setaria adult in a zebra]
• Mesocestoides (tetrathyrida)
• Spirometra mansonoides (sparganum)

Kidneys or Urinary bladder

• Dioctophyma renale [Egg] [Egg] [Egg] [Adult] [Drawing of male bursa]
• Capillaria plica [Egg] [Stichosome with stichocytes]
• Stephanurus dentatus [Egg] [Adult male and females] [Kidney lesion]
• Schistosoma hematobium [Adults]

Liver

• Dicrocoelium dentriticum (Family Dicrocoelidae - aquired from infected ants) [Adult fluke]
• Platynosomum fastosum (Family Dicrocoelidae - aquired from infected lizards) [Adult fluke]
• Eurytrema prycyononis (Family Dicrocoelidae - aquired from infected fish)
• Eurytrema pancreaticum (Family Dicrocoelidae - aquired from infected arthropods)
• Fasciola hepatica (Family Fasciolidae - metacercariae on vegetation)
  • [Fasciola hepatica egg] [Fasciola hepatica adult] [Lymnied snail in typical habitat]
  • Life cycle stages: Miracidium; Sporocyst; Sporocyst; Radia; Radia; Cercariae; Metacercaria

• Fasciolia gigantica (Family Fasciolidae - adults similar to Fasciola hepatica; in tropics or subtropics)
• Fascioloides magna (Family Fasciolidae) [Fascioloides magna adult]
• Clonorchis sinensis (Family Opisthorchidae - a human parasite aquired from infected fish)
  • [Adult Clonorchis sinensis typical of Family Opisthorchidae]
• Amphimerus pseudofelineus (Family Opisthorchidae -aquired from infected fish)
• Metorchis conjunctus (Family Opisthorchidae - aquired from infected fish)
• Capillaria hepatica [Liver lesions] [Histopath of liver lesion filled with eggs]
• Taenia taeniformis (strobilicercus)
• Taenia pisiformis [Cysticerci]
• Taenia fasciolarias (cysticerci)
• Echinococcus granulosus [Hydatid cysts)] [Protoscolices in hydatid cyst]
• Echinococcus multilocularis (Alveolar cysts -- no image) [Protoscolices similar to those in alveolar cyst]
• Thysanosoma actinioides [Adult scolex] [Fringed proglottids] [Fringed proglottids]

Cardiovascular and Respiratory Systems

Cardiovascular system

Parasites infecting  the heart

Parasite	Type of organism	Classification	Usual Hosts
Taenia saginata	Cestode	Taeniidae	Cattle (IH)
Taenia solium	Cestode	Taeniidae	Pigs (IH)
Neospora caninum	Protozoan	Apicomplexa	Dogs, others
Hepatozoon americanum	Protozoan	Apicomplexa	Dogs, others
Sarcocystis	Protozoan	Apicomplexa	Ruminants, others
Toxoplasma gondii	Protozoan	Apicomplexa	Dogs, cats (DH), others
Trypanosoma cruzi	Protozoan	Kinetoplastida	Dogs, other

 

• Dirofilaria immitis [Diagnostic microfilarial stage] [Microfilaria of Dipetalonema reconditum] [Adults in heart] [Intermediate host for heartworms]
• Elaeophora schneideri (Link to A.A Kocan, Wildlife)
• Wuchereria bancrofti [Elephantiasis]
• Brugia brugia (See Wuchereria)

• Heterobilharzia spp [Adult schistosomes]
• Schistosoma japonicum [Adult schistosomes]
• Schistosoma mansoni [Adult schistosomes]

Respiratory System

• Filaroides osleri [Diagnostic larval stage] [Worms in trachea] [Worms in trachea]
• Filaroides milksi [Diagnostic larval stage]
• Aleurostrongylus abstrusus [Diagnostic larval stage]
• Metastrongylus apri [Diagnostic egg stage]
• Protostrongylus stilesi [Lung lesions similar to Muellerius]
• Muellerius capillaris [Lung lesions]
• Capillaria aerophila in lungs; C. boehmi in nasal sinuses [Egg]
• Crenosoma spp
• Parelaphostrongylus tenuis (Link to A.A. Kocan Wildlife Set)
• Angiostrongylus cantonensis (rat brain and pulmonary veins) cause of eosinophilic meningitis in humans.
• Capillaria boemhi [Egg] [Stichosome with stichocytes]
• Dictyocualus viviparus [Bursa and spicules of male]  [Diagnostic larval stage]  [L3 attached to fungal spore]
• Dictyocualus viviparus [Worms in trachea of cow] [Infected lungs]
• D. filaria and D. arnfieldi [Diagnostic larval stage] [Worms in trachea]                             [Lungs of infected sheep]
• Syngamous trachea (See text page 85 Plate IV Figure a)
• Mammomonogamous spp (Similar to Syngamous but in dogs or cattle)
• Migrating larvae of ascarids, hookworms, lungworms and Strongyloides spp pass through lungs.

• Paragonimus kellicoti  [Paragonimus egg] [Paragonimus egg]
• Paragonimus kellicoti [Adult] [Second intermediate host]

• Echinococcus granulosus [Hydatid cyst section] [Protoscolices]

Helminth Parasites of the Somatic and Connective Tissues

Skin and Connective Tissues

• Dracunculus insignis [symbol of aesculapius]  [Copepod intermediate host]
• Micronema, Pelodera and Rhabditis (verminous dermatitis)
• Spirometra mansonoides (plerocercoids or spargana = sparganosis in dogs and humans)
• Dipetalonema reconditum (filarial worm transmitted by fleas; microfilariae confused with Dirofilaria)
• Onchocerca spp (onchocercosis) [Lesion] [Lesion on human]
• Stephanofilaria stilesi [Skin lesion caused by Stephanofilaria]
• Parafilaria spp

Muscles

• Trichinella spiralis (urban and sylvatic transmission of disease)
• Trichinella spiralis adults [Male]   [Female]  [Drawing of Trichinella male and femal] 
• Trichinella spiralis larvae in diaphram muscle [Encysted larvae]  [Encysted larvae]
• Cysticercosis (Taenia solium = pork measles and T. saginata = beef measles) [Cysticerci in muscle]
• Visceral larval migrans (Erratic migration in abberant hosts)

Central Nervious System

• Cysticercosis (Cysticercus cellulosae cysticerci) 
• Hydatid disease (Echinococcus granulosus) [Hydatid cyst section] [Protoscolices]
• Dirofilaria immitis [Neural dirofilariasis]
• Toxocara, Baylisascaris, Anisakis (visceral larva migrans)
• Parelaphostrongylus, Angiostrongylus

Eyes

• Cysticercosis (Cysticercus cellulosae)
• Loa loa (human eye worm)
• Thelazia spp.
• Toxocara canis larvae
• Toxoplasma gondii