TV3001 PARA - pigs endoparasites

Ascaris suum

Location - SI

Lifecycle - Direct

Inf. stage - Embrionated eggs, very resistant

Inf. - Oral, ingestion of embryonated eggs

Strongyloides ransomi

Location - SI

Lifecycle - Direct

Inf. stage - L3, susceptible

Inf. - Oral, transcutaneous and milk

Isospora suis

Location - SI

Lifecycle - Direct

Inf. stage - Sporulated oocysts

Inf. - Oral, ingestion of sporulated oocysts

Trichuris suis

Location - LI

Lifecycle - Direct

Inf. stage - Embrionated eggs, very

resistant

Inf- Oral, ingestion of embrionated eggs

Oesophagostomum spp.

Location - LI

Lifecycle - Direct

Inf. stage - L3, moderately resistant

Inf- Oral, ingestion of L3

Hyostrongylus rubidus

Location - Stomach

Lifecycle - Direct

Inf. stage - L3, susceptible

Inf- Oral

Ascarops strongylina

Location - Stomach

Lifecycle - Indirect

Inf. stage - L3 inside coprophagous beetles (IH)

Inf- Oral, ingestion of beetles

Stephanurus dentatus

Location - kidneys

Lifecycle - direct

Inf. stage - L3, susceptible, earthworms are paratenic hosts

Inf- Oral, transcutaneous (with L3 only)

Metastrongylus spp

Location - Lungs

Lifecycle - Indirect

Inf. stage - L3 inside earthworms (IH)

Inf-Oral, ingestion of earthworms

Trichinella spp.

Location - Somatic musculature

Lifecycle - Direct

Inf. stage - L1 within the musculature

Inf- Oral, ingestion of flesh

important zoonosis

Cysticercus cellulosae (larval stage of Taenia solium that infects humans)

Location - Musculature

Lifecycle - indirect

Inf. stage - Eggs that contain an embryo with 6 hooks (hexacanth)

Inf- Oral, ingestion of eggs that contain hexacanths important zoonosis

Toxoplasma gondii

Location - Musculature , brain

Lifecycle - Indirect

Inf. stage - Sporulated oocystsCysts in musculature/brain

Inf- Oral, ingestion of sporulated oocysts and/or cysts (muscle). important zoonosis

Location -

Lifecycle -

Inf. stage -

Inf-

Intensive/Indoor/’all in-all out’ system

Slatted floor

All in - all outRelatively dry/clean environment (faeces do not accumulate)Regular anthelmintic treatments?

Monitor parasitic infections

No intermediate hosts

Dry, clean environment

Sows treated/washed before being brought to farrowing pen

Early weaning (3-4 weeks)  parasite eggs do not have time to embrionate (A. suum)

Ascaris suum info

The most important/common gastrointestinal worm parasite in pigs with prevalence of 50-75%;

Location: adult parasites in the small intestine but in heavy infections they may be found in the stomach, bile ducts etc;

Ascaris suum can infect and mature in humans

Stout-body,pinkish-yellow;

Three lips surround the mouth;

Prevalence highest in 2–6-month-old pigs

Diagnosis = Live animals with patent infections

NECROPSY = Presence of parasites in the small intestines and ‘milk spots’ in the liver;

Ascaris suum eggs

Thick shell, yellow brown;

Mammilatedouterlayer:

One cell inside.

Survive long time in the environment (up to 6-9 years);

Resistant to usual disinfectants;

Sticky  easily transported by pigs, equipment, worker’s boots, insects (cockroaches, flies), birds etc and get into the rough edges of the concrete material and are not easily removed;

Ascaris suum lifecycle

• Unembrinated eggs (not infective) are passed in the faeces;

Optimum temperature for development: 30-33C

At optimum temperature the infective larvae form inside the eggs in 13-18 days, at 18-20C they form in 30-40 days;

Eggs do not develop (but survive) at temp lower than 15C;

Larvae hatch in the intestine and migrate to liver -> heart -> lungs -> trachea -> pharynx -> small intestine (10-15 days PI) where they mature

Ascaris suum pathogenesis

Larvae may produce lesions in the liver (milk/white spots) and lungs;

Adult worms cause lesions in the digestive tract;

Liver: milk/white spots (larvae) = Cloudy/whitish spots up to 5 mm in diameter on the surface of liver

Small hemorrhages into the alveoli and bronchioles,oedemainfiltrationof the surrounding pulmonary parenchyma with eosinophils and other cells  lungs compromised by these lesions become more susceptible to other conditions

Small intestine (adult worms)

Compete with the host for nutrients  retard growth;

Heavy infections → may block the gut;

Perforate the intestine  peritonitis;

Immunogenic parasites

pigs continuously exposed acquire a high degree of resistance

Ascaris suum treatment

• Heterocyclic compounds

• Piperazine

• Benzimidazoles

• Fenbendazole • Flubendazole

• Imidazothiazoles

• Levamisole

• Tetrahydropirimidines

• Pyrantel

• Morantel

• Macrocyclic lactones

• Abamectin? • Ivermectin • Doramectin

Ascaris suum intestinal stages susceptible to:

Heterocyclic compounds

- Piperazine

Benzimidazoles

Fenbendazole (Safe-guard), Flubendazole (Flubenol)

Imidazothiazoles

–Levamisole

Tetrahydropirimidines

– Pyrantel, oxantel, Morantel

Macrocyclic lactones (MLs):

Ivermectin, Doramectin;

It is recommended to

Destroy the faeces collected 3-4 days after treatment (contain worms & eggs);

Improve hygiene to destroy eggs (clean floors, steam etc);

Suspected pneumonia

Levamisole, Fenbendazole, Ivermectin, Doramectin

Ascaris suum: Control

Treat boars 2-4 times/year;

Treat pregnant sows two weeks before farrowing;

Wash the sow carefully 4-14 before placing it in the farrowing pen;

Clean and disinfect the farrowing pen

Treat piglets 10-14 days before transfer to clean and disinfected fattening unit and 6 weeks later;

• Medicated food

Ring the snout of the sows

Strongyloides ransomi (suis)

Location: small intestine, embedded into mucosa;

Parasitic and free-living stages;

Parasitic stage: only females (less than 5 mm long);

Eggs: 45-55 μm/26-35μm, thin shell, contain a larva when laid;

Strongyloides ransomi lifecycle

Eggs reach the environment with faeces → larvae hatch and can follow

Homogonic development

Heterogonic development

Within host

After infection L3 can:

a) Mature to (partenogenetic) females in the SI

b) Enter hypobiosis;

Strongyloides ransomi: epidemiology

Present in outdoor and indoor systems;

Infections are prevalent in warm climates;

Infections can be found in all age categories but they are clinically significant in suckling pigs;

Sows are important sources of infection;

Strongyloides ransomi: clinical signs

May appear in pigs as young as 5-10 days

(infection via milk);

Diarrhea, dehydration, emaciation, anorexia, anemia etc;

Strongyloides ransomi: diagnosis

Clinical signs;

History (young age);

Finding eggs in the faeces;

Strongyloides ransomi: treatment and control

• MLs (Ivermectin, Doramectin) & Levamisole are effective chemicals;

Treatment of the sows with Ivermectin 3-16 days before parturition prevents transfer of the larvae via milk

Hygiene, cleaning the pens before farrowing

Macracanthorhynchus hirudinaceus

Location: small intestine of pigs (humans): a nodule is often present at the point of attachment to the small intestine;

Morphology (adult worms);

Size: up to 35 cm;

Proboscis provided with around 6 transverse rows of hooks;

Intermediate hosts: May beetles, dung beetles, water beetles

Nodular lesions that might be invaded by bacteria;

Perforation of the gut  peritonitis;

Diarrhoea, weight loss etc;

Diagnosis

• Detection of eggs in the faece

Treatment

Ivermectin

Doramectin