Pig nematodes Flashcards
What are nematodes of indoor + outdoor pigs?
*Ascaris suum
*Strongyloides ransomi
*Trichuris suis
*Oesophagostomum spp.
What are nematodes of outdoor pigs only?
*Hyostrongylus rubidus
*Metastrongylus apri
What are characteristics of Ascaris suum?
*Ascarid = L2 infective stage
*Large fleshy white worms
*Direct life cycle
*Highly resistant eggs - thick walled 70um
*Infections = strong immunity
What is the life cycle of Ascaris suum?
*Eggs passed in faeces
*Develop on ground - temp dependent - 4 weeks
*Paratenic host - earthworm / dung beetles
*Hepato-tracheal / pulmonary migration - larvae from liver to lungs
*Coughed up + swallowed develop to L4/L5 in SI
*PPP = 8weeks
What is seen with Ascaris suum infection?
*Liver - fibrous reaction = ‘milk spot’
*Lungs = transient pneumonia
*Adults in SI = poor weight gain + mechanical blockage
How is Ascaris suum diagnosed?
*Post mortem - milk spot liver
*Transient resp disease
*Reduced weight gain
* MgSO4 Egg flotation method
What is the treatment + control of Ascaris suum?
*Anthelmintics - MLs + BZs
*Non-anthelmintics = steam cleaning indoor pens
What animals does Strongyloides ransomi affect?
*Young animals - good immunity after exposure
What are characteristics of Strongyloides ransomi?
*Small - 6mm
*Hair-like
*No ovijectors
*Small eggs - 40-50um , thin shelled + embryonated
What is the unique life cycle of strongyloides?
*Free living + parasitic cycle
*Free living = L3 develop develop t L4 + L5 = free living males + females in environment
*Parasitic life cycle = L3 ingested / percutaneous infection + migrate through body to udders / SI where they develop to FEMALE adults - asexual lifecycle (Parthogenesis)
*PPP = <15days
*Can be passed to piglets in milk as arrested larvae in udder
What are the clinical signs of strongyloides infection?
*Adults = strong immunity = no CS
*Piglets = diarrhoea, anaemia, emaciation
+ death if <2week old
How is strongyloides infection diagnosed?
*Eggs in faeces from anus so not confused with free living stage - patent infection
*Abattoir reports - adults in intestinal mucosa + Baermann of minced tissues
What is the treatment + control of strongyloides?
*Anthelmintics - MLs + BZs
*Keep environment clean
What are characteristics of Trichuris suis?
*Whip worm
*Found in LI
*Highly resistant eggs - viable for 11years (2mucoid plugs)
*Direct lifecycle
What is the lifecycle of trichuris?
*Eggs develop >16oC - 10-12weeks
*Infective stage = egg containing L1
*PPP = 6-8weeks
What does trichuris cause in pigs?
*Weight loss
*Colitis in growers
*Resilient to many anthelmintics
What are characteristics of oesophagostomum?
*Found in LI
*Adults = 2cm + cephalic vesicle
*Direct + typical strongyle lifecycle
*PPP 3-6weeks
What does oesophagostomum cause?
*Nodules - intestinal wall = thickened + necrotic
*Higher prevalence in older pigs
How is oesophagostomum diagnosed?
*Post mortem = nodules
*Faecal exam - larval culture - differentiate from hyostrongylus
What is the treatment + control of oesophagostomum?
*BZs + MLs
*Good sanitation
What does Hyostrongylus rubidus cause?
*Direct life cycle - found in gastric glands of stomach
*Parasitic gastritis
*Heavy infections = inappetance, anaemia, weight loss
Thin sow syndrome
How is Hyostrongylus rubidus diagnosed?
*Faecal exam - larval culture
*Post mortem
What is the treatment of hyostrongylus rubidus?
*BZs + MLs
What is the life cycle of Metastongylus apri?
*L1 infects earthworm - develop to L3 (can survive in earthworm for 7 year)
*Earthworm ingested by pig
*L3 released into gut - L3+ L4 in mesenteric lymph node
*L4 migrates to lung via lymphatics + blood
*Matures in lungs - Lumen of bronchi
*2.5-5cm
*PPP = 3-4weeks
What does Metastrongylus apri cause in pigs?
*Seen in 4-7month old pigs
*Catarrhal + eosinophilic bronchiolitis
Persistent cough, dyspnoea + nasal discharge
*Reduced appetite + weight gain
*Exacerbates other resp diseases
How is metastrongylus apri diagnosed?
*Adults visible in bronchi
*Faecal exam + baermann technique
What is the treatment + control of metastrongylus apri?
*MLs + BZs
*Minimising contact with intermediate host
