Ascarids

Question 1

Ascarid lifecycle

Answer 1

Question 2

Ascarid of pigs and humans

Answer 2

Ascaris suum

Ascaris lumbricoides

Question 3

Ascarid of horse and donkey

Answer 3

Parascaris equorum

Question 4

WHO significance of Ascaris lumbricoides

Answer 4

infects 1 billion people globally

Question 5

Economic impact of ascarids?

Answer 5

Production loss

-lumina feeders, malnutrition, reduced weight gain, stunting of growth

Question 6

Clinical Disease

Answer 6

• diarrhoea (yellow and pasty), colic, vomiting (may vomit worms)
• intestinal ileus, blockage, rupture -> peritonitis
• bile duct occlusion (cholestasis)
• gall stones (in humans)

Question 7

Significane of hepatopulmonary migration?

Answer 7

Can cause mechanical and inflammatory damage to organs

Milk spots in pigs -> condemned at slaughter

Eosinophilic pneumonia - calves, piglets, pups, kittens, foals

• predisposes to viral and bacterial pneumonias
• damaged lungs do not regenerate, FOALS!

Question 8

Zoonotic ascarids in humans

Answer 8

• A.suum + lumbricoides infect humans
• Larvae of Toxocara canis and T. cati cause ocular and visceral larva migrans
• Larvae of anisakids cause eosinophilic/gastritis

Question 9

Features of Toxocara Canis

Answer 9

• Direct and paratenic LC
• Transmammory and transplacental transmission
• L3 in egg -> HPM

PPP

• TP; 2 weeks (larva in lungs)
• TM+PH; 2-3 weeks
• eggs; 5 weeks
• zoonotic

Question 10

Features of Toxocara cati

Answer 10

• Direct and paratenic LC
• Transmammory transmission
• L3 in egg -> HPM

PPP

• TM+PH; 3 weeks
• eggs; 8 weeks
• zoonotic

Question 11

Features of Toxocaris leonina

Answer 11

• Direct and paratenic LC
• No HPM

PPP

-eggs; 7-10 weeks

Question 12

Somatic migration of Toxocara

Answer 12

Some larvae in circulation end up in muscle instead of the lungs -> cause granulomatous lesions -> in 3rd trimester of pregnancy they move into the puppy TP or TM when suckling

Question 13

Stage passed in faeces?

Answer 13

Unembryonated egg

Question 14

What stage is infective?

Answer 14

Embryonated egg (L2 in paratenic, L3 in direct)

Question 15

Duration taken to reach infectivity in the soil

Answer 15

2 weeks

Question 16

Time that infective stage survives in soil?

Answer 16

5-10 years

Question 17

What happens with somatic migration?

Answer 17

No eggs does not mean no infection! esp in breeding females

Question 18

Diagnosis of ascarids

Answer 18

Faecal float

Question 19

Identify in the correct order

Answer 19

Ascaris, Toxocara, Toxocaris, Parascaris

Question 20

Identify this worm

Answer 20

Toxocara

Question 21

Identify this worm

Answer 21

Toxocaris

Question 22

Identify these worms in order

Answer 22

T. cati, T. canis, Toxocaris leonina

Question 23

Pulic Health significance of Toxocara

Answer 23

• young humans
• larvae may be encapsulated in tissue for years
• > Uticaria or fever, hepatomegaly, eosinophilia, cough
• usually self limiting, but potentially serious - eosinophilic encephalitis, myocarditis etc
• ocular larval migration, treatment is unsuccessful

Question 24

Ascarids of birds

Answer 24

Ascaridia spp (SI)

Heterakis spp (caeca)

Question 25

Features of bird ascarids

Answer 25

- Direct LC - PPP ~4-6 weeks - eggs take 2 weeks to embryonate, viable for a year. - Earthworms are transport host.

Question 26

Ascaridia in chicken?

Answer 26

Ascardia galli

Question 27

Effects of Ascaridia galli

Answer 27

- Larvae develop into adults in duodenal and SI wall -\> synchronous eruption of larvae -\> enteritis +/- haemorrhagic - Adult worms -\> intestinal occlusion - Nutritional deficiency -\> increased susceptibility to disease, poor growth etc

Question 28

Lesions in affected turkey caused by?

Answer 28

Heterakis gallinarum

Question 29

Features of Heterakis gallinarum?

Answer 29

- may cause caecak thickening in chickens - tranmission of Histomonas meleagridis through egg - protozoa highly pathogenic in turkeys "black disease" - \> necrotising typhlitis and focal necrosis of liver

Question 30

Size of Heterakis?

Answer 30

1.5cm

Question 31

Size of Ascaridia

Answer 31

12cm

Question 32

How to manage ascardids in extensive system?

Answer 32

Challenging! -Rotate pastures, especially young animals

Question 33

How to manage ascarids in intensive system?

Answer 33

Hygiene - removal of faeces Decontamination of premises (bleach, flame gun) Rodent and pest control (cockroaches) Don't feed raw meat Treat and quarantine new animals Deworm at regular intervals

Question 34

What animals to treat?

Answer 34

- clinically affected (watch out for obstruction by removing all worms at once) - young animals to prevent likelyhood of disease (just prior to PPP) - Prophylactic prevention of placental and lactogenic infections in pups and kittens

Question 35

Outdoor system treatment regime (pigs)

Answer 35

- Treat growers at 8 weeks - Treat sows and boars every 3 months to reduce pasture contamination - treat sows 7-14 days prior to farrowing - use levamisole, ivermectin, morantel, piperazine (narrow spectrum) - test herd every 6 months

Question 36

How to treat foals?

Answer 36

Deworm foals every 2 months (rotating MLs, BZs, pyrantel) - start at 2 months old until they are 1 year old - FEC prior to deworming in spring - rotate pastures

Question 37

How to treat puppies?

Answer 37

- treat at 2 weeks old and then every 2 weeks until 10 weeks old -\> monthly until 6mo - treat bitch at the same time

Question 38

Treat adult dogs?

Question 39

Treatment of the pregnant bitch

Answer 39

- can't kill arested larvae but kill them when the emerge into the bloodstream. - Fenbendazol 50mg/kg daily pour on from day 40 of pregnancy to 14+ days post whelping - Selamectin topically 40d and 55d of pregnancy - labeled use of monthly moxidectin topically

Question 40

Kitten Treatment

Answer 40

- De-worm kittens at 3 weeks of age and then every 2 weeks until 8 weeks old, then monthly until 6 months old. - de worm queen at the same time

Question 41

How to de worm adult cat?

Answer 41

Faecal exam and deworm according to risk -prevent lactogenic transmission to kittens by applying selamectin, moxidectin or emodepside topically to queen at the end of gestation

Question 42

Lifecycle of fish born Anisakidae

Answer 42

Question 43

Anisakidiasis

Answer 43

Aquired through injesting L3 in raw, insufficiently cooked or smoked fish. Invasive (1hour - 2 days) - penetrate gut mucosa - Eosinophilic gastritis, eneritis - acute vomiting and diarrgoea - allergic response to antigens \*\*Cook well or freeze for more than 7 days