Practical 20: Diagnosis of Parasites in Horses and Pigs

What is the important protozoa found in horses?

*Eimeria leuckarti*

Describe the oocyst of *Eimeria leuckarti*

1. medium (70-85μm)
2. oval
3. 2 thick shells, micropyle
4. unsporulated
5. dark brown

Which trematode eggs can be found in horses?

*Fasciola hepatica, Dicrocoelium dendriticum, Paramphistomum spp.*

Which diagnostic method must be used to see trematode eggs?

sedimentation method

For which type of egg must perianal scrapings be used?

*Oxyuris equi* (horse pinworm)

Which orders of ectoparasites are important in horses?

Diptera, Phthiraptera, Acarina

Which species of Diptera are important for horses?

*Stomoxys calcitrans*

*Tabanus bovis*

*Hippobosca equina*

*Rhinoestrus purpureus*

*Gasterophilus intestinalis*

Which species of Phthiraptera is important for horses?

*Damalina equi*

What are important non-burrowing lice from Acarina?

*Ixodes ricinus, Dermacentor marginatus, Dermacentor reticulatus*

What are important burrowing lice from Acarina?

*Sarcoptes scabiei* var. *equi, Demodex equi, Psorptes equi, Chorioptes equi*

What is the main method of intravital diagnosis of helminth eggs?

faecal examination by floatation methods

Which floatation solution is used for faecal examination in horses?

Breza

What family is important from Cestodes for horses?

Anoplocephalidae

What are important species of Anoplocephalidae in horses?

*Anoplocephala perfoliata, Anoplocephala magna, Paranoplocephala mamillana*

Describe the eggs of family Anoplocephalidae

1. small - medium (50-80 x 50μm)
2. irregular spherical/triangular
3. three thick shells
4. embryonated (oncosphere and pyriform apparatus)
5. light grey

What type of life cycle do the species of Anoplocephalidae have?

indirect (biohelminth)

What are the intermediate hosts of Anoplocephalidae?

mites (Galumnidae, Oribatulidae, Carabodidae)

Describe the adult *Anoplocephala perfoliata*

1. length: 20-25 x 1-1.5 cm


1. rounded scolex with 4 suckers with a lappet behind each of the suckers

What are important orders of Nematodes in horses?

Rhabditida, Strongylida, Ascaridida, Oxyurida, Spirurida

What is the important species of Rhabditida in horses?

*Strongyloides westeri*

Describe the egg of *Strongyloides westeri*

1. thin shells
2. small
3. oval, symmetrical
4. embryonated (L1)
5. transparent

What type of life cycle do the species of Strongylidae have?

direct (geohelminth) (can be parasitic or non-parasitic)

How can the family Strongylidae be divided?

large strongyles, small strongyles

What are examples of large strongyles?

*Strongylus vulgaris, Strongylus equinus, Strongylus edenatus, Triodontophorus serratus, Triodontophorus brevicauda, Triodontophorus tenuicollis, Triodontophorus minor*

What are examples of small strongyles?

*Cyanthostomum spp., Cylicocylus spp., Cyclicostephanus spp., Cyclicodontophorus spp.*

Which of the strongyles migrate to other organs in the body of the DH?

large strongyles

Describe the egg of *Strongylus spp.*

1. medium
2. oval, symmetrical
3. 2 thin shells
4. unembryonated (few blastomeres)
5. grey

Describe the egg of *Triodontophorus spp.*

1. large
2. oval, symmetrical
3. 2 thin shells
4. unembryonated (few blastomeres)
5. grey

Describe the egg of small strongyles

1. medium
2. oval, symmetrical
3. 2 thin shells
4. unembryonated (few blastomeres)
5. grey

What are important species of Strongylida for horses?

Strongylidae, Trichostrongylidae

What is the important species in Trichostrongylidae for horses?

*Trichostrongylus axei*

What type of life cycle do Trichostrongylidae species have?

direct (geohelminth)

Describe the egg of *Trichostrongylus axei*

1. medium (75-90 x 40-43μm)
2. elliptical, asymmetrical
3. 2 thin shells
4. unembryonated (many blastomeres)
5. grey

What methods are used for the diagnosis of Strongyles?

faecal floatation, necropsy

What is the important species of Dictyocaulidae in horses?

*Dictyocaulus arnfieldi*

Describe the egg of *Dictyocaulus arnfieldi*

1. medium (80-100 x 50-60μm)
2. oval
3. 2 thin shells
4. embryonated
5. grey

What method is used to diagnose *Dictyocaulus arnfieldi*?

larvoscopic methods

What is the important species from Ascaridida in horses?

*Parascaris equorum*

Describe the egg of *Parascaris equorum*

1. medium (80-100μm0
2. spherical
3. 3 thick shells with an outer pitted coat
4. unembryonated (one blastomere)
5. dark brown

What type of migration does *Parascaris equorum* have?

entero-hepato-pulmonal

What type of life cycle does *Parascaris equorum* have?

direct (geohelminth)

Which larval stages of *Parascaris equorum* migrate?

L2-L5

What is the important species of Oxyuridae in horses?

*Oxyuris equi*

What type of life cycle does *Oxyuris equi* have?

direct (geohelminth)

Where is a sample taken for diagnosis of *Oxyuris equi*?

perianal scraping

Describe the egg of *Oxyuris equi*

1. medium (85-100 x 40-50μ)
2. ovoid, slightly flattened on one side (asymmetrical)
3. 2 thin shells with mucoid plug at one pole
4. unembryonated
5. yellow

What are important families in Spirurida for horses?

Habronematidae, Thelaziidae, Filariidae

What are the important species of Habronematidae?

*Habronema muscae, Habronema microstoma*

Describe the egg of *Habronema spp.*

1. small
2. oval
3. 2 thick shells
4. embryonated (L1)
5. transparent

What type of life cycle do *Habronema spp.* have?

indirect (biohelminth)

What are the intermediate hosts of *Hebronema spp.*?

muscid fly (*Musca, Stomoxys*)

Where are *Habronema spp.* found in horses?

stomach

What is the important species of Thelaziidae?

*Thelazia lacrimalis*

Where is *Thelazia lacrimalis* found in horses?

conjunctival sacs and lacrimal duct

What type of life cycle does *Thelazia lacrimalis* have?

indirect (biohelminth)

What is the intermediate host of *Thelazia lacrimalis*?

face fly

What are the important species of Filariidae?

*Setaria equina, Onchocerca reticularis, Onchocerca cervicalis*

Where is *Setaria equina* found in the body?

peritoneal cavity, pleural cavity, lungs, eye

What diagnostic method is used for *Setaria equina*?

blood smear (microfilariae in blood)

Where are *Onchocerca spp.* found in the body?

nuchal ligament

What type of life cycle do *Onchocerca spp.* have?

indirect (biohelminths)

What is the intermediate host of *Onchocerca spp.*?

midges (*Culicoides*)

Which species are found in the small intestines of horses?

*Eimeria leuckarti, Anoplocephala magna, Paranoplocephala mamillana, Strongyloides westeri, Parascaris equorum*

Which species are found in the large intestines of horses?

*Stronyglus spp.,* small strongyles, *Triodontophorus spp., Oxyuris equi*

Which species are found in the stomach of horses?

*Hebronema spp., Trichostrongylus axei*

What are important genera of protozoa for pigs?

*Eimeria, Cystoisospora, Cryptosporidium*

Which *Eimeria spp.* are important for pigs?

*Eimeria debliecki, neodebliecky, polita, scabra, spinosa, perminuta*

Describe the oocysts of *Eimeria*

1. small (18-45μm)
2. oval
3. 2 thin shells
4. sporulated/unsporulated
5. transparent

Which species of *Cystoisospora* is important for pigs?

*Cystoisospora suis*

What is an important species of lice for pigs?

*Haematopinus suis*

What is an important species of mites for pigs?

*Sarcoptes scabiei* var. *suis*

What is an important (if rare) trematode in pigs?

*Fasciola hepatica*

Why can you not find eggs of cestodes in faeces of pigs?

pigs are only IH for tapeworms

Which cestodes can be found in pigs?

*Taenia solium, Taenia hydatigena, Echinococcus granulosus*

In which form is *Taenia solium* found in pigs?

*Cysticercus cellulosae*

In which form is *Taenia hydatigena* found in pigs?

*Cysticercus tenuicollis*

In which form is *Echinococcus granulosus* found in pigs?

*Echinococcus granulosus*

Which species found in Acanthocephala is important for pigs?

*Macracanthorhynchus hirundinaceus*

What type of life cycle does *Macracanthorhynchus hirundinaceus* have?

indirect (biohelminth)

What is the intermediate host of *Macracanthorhynchus hirundinaceus*?

dung beetle

Describe the egg of *Macracanthorhynchus hirundinaceus*

1. large (110 x 65μ)
2. oval, symmetrical
3. 3 thick shells
4. embryonated (acanthor)
5. dark brown

What are important orders on Nematodes in pigs?

Rhabditida, Strongylida, Ascaridida, Enoplida

What is an important species in Rhabditida for pigs?

*Strongyloides ransomi*

Describe the egg of *Strongyloides ransomi*

1. small
2. oval, symmetrical
3. 2 thin shells
4. embryonated (L1)
5. transparent

What are important families in Strongylida for pigs?

Trichostrongylidae, Chabertiidae, Syngamidae, Metastrongylidae

What is the important species in Trichostrongylidae for pigs?

*Hyostrongylus rubidus*

Describe the egg of *Hyostrongylus rubidus*

1. medium
2. ovoid, symmetrical
3. 2 thin shells
4. unembryonated (many blastomeres)
5. grey

What is the important species in Chabertiidae for pigs?

*Oesophagostomum dentatum*

Describe the egg of *Oesophagostomum dentatum*

1. medium
2. ovoid, symmetrical
3. 2 thin shells
4. unembryonated (may blastomeres)
5. grey

What is the important species of Syngamidae for pigs?

Stephanurus dentatus

What sample is needed for the diagnosis of *Stephanurus dentatus*?

urine (eggs in urine sediment)

What are the important species of Metastrongylidae for pigs?

*Metastrongylus pudendotectus, Metastrongylus apri, Metastrongylus salmi, Metastrongylus confusus*

Describe the egg of *Metastrongylus spp.*

1. small
2. oval, symmetrical
3. 2 thick shells
4. embryonated (L1)


1. transparent

What type of life cycle do *Metastrongylus spp.* have?

indirect (biohelminths)

What are the IH of *Metastrongylus spp.*?

earth worms

What is very characteristic for the males of *Metastrongylus spp*?

form very large *bursa copulatrix*

What species is of Ascaridida is important in pigs?

*Ascaris suum*

What type of migration does *Ascaris suum* have?

entero-hepato-pulmonal

Describe the egg of *Ascaris suum*

1. medium
2. spherical
3. 3 thick shells
4. unembryonated (1 blastomere)
5. dark brown

What type of life cycle does *Ascaris suum* have?

direct (geohelminth)