PO Ecto/Endoparasites Flashcards
Describe the morphology of an Ascaris suum egg.
70um
Thick, pitted wall
Describe the morphology of Ascaris suum adults
Large - 15-25cm
Males have curled tail (like a pig)
What is the intermediate host of Ascaris suum?
Earthworm
Outline the lifecycle of Ascaris suum.
- Eggs in pig faeces
- Development on grass for 4 weeks
- Ingested by earthworm - l2 hatch from eggs
- Ingested by pig
- Hepato-pulmonary migration
- Coughed up and swallowed and adult develop in the GIT
What is the PPP of Ascaris suum?
8 weeks
What three features of the Ascaris suum lifecycle lead to clinical signs in the pig?
- Hypersensitivity to migration - pneumonia and milk spot liver
- SI infection - poor wt gain and mechanical blockage
- Liver condemnation and decreased wt gain - reduced economic gain
Describe this lesion
Multifocal to coelescing round pale tan/ white lesions ranging from .5x.5 cm to 2x2 cm. Soft to touch and affecting one lobe of the liver.
Chronic multifocal severe fibrosing parasitic hepatitis
Ascaris suum
How are Ascaris suum outbreaks controlled?
Condemnation of carcasses
Quick immunity develops with infection
Steam clean accomodation to remove eggs
Reduce contact with paratenic host - worms (outdoor not possible)
Which strongyloides are known to affect pigs?
Describe the morphology of the nematode.
Strongyloides ransomi
- Small - 6mm
- Hair-like
- Small eggs
Describe the lifecycle of strongyloides ransomi.
- Free-living - moist, warm habitats
- Parasitic
- Percutaneous infection
- Migration to:
- Lungs
- Small intesting
- Mammary glands - TMT
- Excreted in faeces
What transmission routes are utilised by Strongyloides ransomi?
Percutaneous
TMT in sows
What clinical signs are observed in an infection of Strogyloides ransomi?
Diarrhoea and weight loss in piglets
Treat via BZ/ML and biosecurity improvements
Whipworm
Trichuris
Describe the morphology of an adult Trichuris.
Anterior to posterior thickness
Anterior end is thinner
What is th PPP of Strongyloides ransomi?
15 days
Describe the morphology of a Trichuris egg.
Lemon shaped
Contain L1
Highly resistent in the environment
Describe the recognisable morphology of an adult Oesophagostomum.
2cm adults
Cephalic vesicle
Which other nematode are Hyostrongylus similar to in other species?
Ostertagia
What feature of Metastrongylus apri is indicative of larval morphology?
L1 tail knob
What is the intermediate host of Metastrongylus apri?
Earthworm
Outline the lifecycle of Metastrongylus apri.
- Egs in faeces
- Ingested by earthworm and develop from L1-L3
- Ingested by pig
- SI-LN- Lungs migration
- Coughed up and swallowed
- Adults in SI
What clinical signs are associated with infections of Metastrongylus apri?
- Catarrhal/ eosinophilic bronchitis
- 4-7 m/o pigs
- Cough, dyspnoea, nasal discharge
- Decreased wt gain
- Inappetence
Name three zoonotic parasites associated with pigs.
- Trichinella spiralis
- Balantidium coli
- Taenia solium
Outline the clinical signs associated with human Trichinosis.
- Fever
- Oedema
- Muscle pain
- Periorbital oedema
- Myocarditis
- Meningitis
When are humans at risk of ingesting Trichinella spiralis?
When eating undercooked and contaminated meat (eg pig, horse, game etc)
Outline the lifecycle of Trichinella spiralis
- Larvae are ingested
- Migrate to muscle
- Encyst in porcine muscle
- Ingested by human
- L1 released, develop to adults and die
What two transmission methods are employed by Trichinella spiralis?
Free living parasites are ingested
Faecal-oral route
What legislation has been put in place to protect humans from Trichinosis?
2014 EU legislation - all boars, sows and pigs from non-controlled housing must be tested at slaughter.
How is Balantidium coli transmitted to humans?
Faecal-oral route
Balantidium coli causes what type of disease in humans? What groups are more readily affected?
Intestinal disease
More readily affects immunocompromised humans and malnurished (low stomach pH)
How can Taenia solium be transmitted to humans?
What disease does each method lead to in the human?
- Eating cysts in undercooked pork - tapeworm develop in small intesting - Definitive host
- Ingesting eggs - metacestode develops in the brain and neural tissue causeing Neurocysticercosis - Intermediate host
Neurocystercosis
Cysts of Taenia solium developing in the brain of human
Isospora suis causes what clinical signs in the pig?
Piglet enteritis
Diarrhoea unresponsive to antibiotics
Low/ -ve oocyst counts
Outline the lifecycle of Isospora suis.
- Oocysts in faeces
- Develop and sporulate in the environment
- Ingested by pig
- x2 asexual reproductive cycles = Merozoites in schizonts
- x1 sexal reproduction cycle = Produces zygotes
How is Isospora treated in pigs?
Sulphonomides
What clinical signs are associated with Sarcoptes scabei in pigs?
- Ear lesions spreading to back flank and abdomen
- Severe immune reaction
- Pruritis
- Erythema
- Dermal hyperplasia
- Secondary bacterial infection
Tx. Macrocyclic lactones
What clinical signs are associated with Haematopinus suis
Decreased feeding/ growth rates
Decreased hide quality
Intense itching
