2.4. Roundworms

Question 1

Answer 1

Haemorrhage in lung as a result of lung migration of Ascaris suum but respiratory symptoms are rare for this infection

Question 2

Answer 2

Ascaris suum

Huge size —> absorb lots of nutrients —> slower growth of pig

Question 3

Answer 3

3 labia of roundworm (not possible to distinguish species by morphology but by the host!)

Question 4

Answer 4

Egg of Ascaris suum
Outer part of the egg can come off

Very durable! Almost impossible to get rid of parasite once it’s on the farm. Resistant to most disinfectants, can survive many years

Question 5

Answer 5

Egg of Ascaris suum
Outer part of the egg can come off

Flotation test. Dense solution

Question 6

Life cycle of Ascaris suum

Answer 6

Question 7

Prepatent period for Ascaris suum

Answer 7

45-60 days

If animals are treated within this period -> no eggs are shed

Sows are often washed to decrease the chance of infecting the piglets through fecal material

Question 8

Answer 8

Roundworm infection of the horse -> Parascaris equorum
Mainly lungs are damaged -> haemorrhagic inflammation
Mainly in foals

Question 9

Host: horse

Answer 9

Roundworm of the horse -> Parascaris equorum
Adult worms can reach 20-40 cm in length

Question 10

Host: horse

Answer 10

Roundworm of the horse -> Parascaris equorum
Adult worms can reach 20-40 cm in length

Question 11

Answer 11

3 labia of the roundworm
If host is horse —> Parascaris equorum
If host is pig —> Ascaris suum

Question 12

From horse

Answer 12

Parascaris equorum

Question 13

Is there correlation between number of eggs and number of adult worms in case of PArascaris equorum?

Answer 13

No, because 1 adult worm can lay up to 200.000 eggs per day

In case of Strongylus there is correlation between these two

Question 14

What is special about Toxocara life cycle ?

Answer 14

Adult worms can develop only in young animals (calves in case of Toxocara vitulorum)

Worms produce acids that make meat of calves smell

Question 15

In what animals can Toxocara vitulorum eggs be found?

Answer 15

In feces of young calves (<4 months)

If adult cow eats contaminated grass, it gets infected with L3 larva -> in cows it will migrate to mammary gland and be dormant there —> in case of pregnancy these worms will “activate” because of hormones —> will infect calves through milk

In case of bulls worms will stay dormant and no further infection will happen

Question 16

Answer 16

Eggs of Toxocara vitulorum - rough surface

Question 17

Life cycle of Toxocara species of carnivores

Answer 17

zoonotic (T. canis, T. cati)

In adult animals worms will be dormant but in the young animals will be “ascaroid-type” life cycle (intestines - liver - lung - intestines)

Paratenic hosts exist also (rodents, birds)

Question 18

Can transplacental transmission happen in case of Toxocara canis ?

Answer 18

YES! Newborn puppies can be born already infected!

Transmammary (lactogenic) transmission also happens

Question 19

Is Toxocara canis zoonotic?

Answer 19

YES. Usually asymptomatic. But if larva gets into the eye/CNS/liver, then disease can be very serious but it’s not very common

Question 20

Answer 20

Toxocara canis - cuticular wings

Question 21

Answer 21

Toxocara canis - cuticular wings

Question 22

Answer 22

Toxocara canis - no copulatory bursa but papillae

Question 23

What are 2 main worms that newborn puppy can be infected with?

Answer 23

• Toxocara canis - roundworm
• Ancylostoma caninum - hookworm - much smaller, thinner, haemorrhages in small intestines as they feed on blood

Question 24

Differences between life cycles of Toxocara canis and Toxocara cati

Answer 24

Toxocara cati adult worms are not dormant in the body of the adult cat but living in the intestines and produce eggs!!

Question 25

Answer 25

*Toxocara cati* - egg is a bit more oval than in *Toxocara canis* but main thing that it’s ***Toxocara***

Question 26

Difference in morphology of different *Toxocara species* adult worms

Answer 26

1. Cuticular wings 2. Different shape of Oesophagostomum

Question 27

Answer 27

*Toxocara cati*

Question 28

What is the type of life cycle of the *Toxocara leonina*?

Answer 28

Ascaridioid type —> much less dangerous (**no extraintestinal migration**) and non-zoonotic Affects only intestines

Question 29

Answer 29

*Toxocara leonina* eggs - no grooves and holes on the surface of the egg

Question 30

Roundworms of poultry

Answer 30

***Ascaridia** galli, collumbae, dissimilis* *Ascaridia galli* — 5-12 cm — fowls, turkey, duck *Ascaridia columbae* — 3-7 cm — pigeon *Ascaridia dissimilis* — 3-7 cm — turkey

Question 31

Host: poultry

Answer 31

***Ascaridia***

Question 32

Host: poultry

Answer 32

***Ascaridia***

Question 33

Answer 33

*Ascaridia galli* (can be confused with *Heterakis gallinarum* but they have preanal sucker!)

Question 34

Answer 34

*Ascaridia* or *Heterakis* egg

Question 35

Answer 35

Paratenic hosts of *Ascaridia*

Question 36

Life cycle of *Heterakis gallinarum*

Answer 36

Question 37

What is special about *Heterakis gallinarum*

Answer 37

Often is infected with *Histomonas meleagridis* !!! Because for Histimonas is very difficult to survive in outside world as it has only 2 forms: amoebid and flagellated —> infects eggs of *Heterakis gallinarum* to survive in the environment

Question 38

Answer 38

*Heterakis gallinarum* - males have spicules of different size and cuticular wings around the tail

Question 39

Answer 39

*Heterakis gallinarum* - males have spicules of different sizes + cuticular wings on the tail

Question 40

Answer 40

*Heterakis gallinarum* egg But it’s very difficult to distinguish from *Ascaridia* egg so in midterm we should say that’s it’s one of the two