21. Pig Helminths Flashcards
What is ascarus suum?
large roundworm of pigs
distribution: worldwide - very common
Parasite of grower pigs (2-5 months), has highest prevalence, highest intensity
morphology - big white worms
What is the lifecycle of A. suum?
adults in Si - extremely reproductive (2mil eggs per day)
eggs become infective (L3) - temperature dependant development (days to months) extremely hardy eggs (7-10 yr survival)
hepato-tracheal migration after ingestion of eggs
What is the life cycle of A. suum in the liver, lungs, return to SI, PP and dx?
lifer - 3-4 days PI
lungs 4-6 days PI
return to SI 7-8days PI
PPP 8-6wks
Dx. scarid eggs
in feces - fecal float
That is the pathogenesis of a. suum in the liver?
migrating larvae - liver - first infection - physical damage
Following infections - hypersensitivity
Allergic inflam or milk spots
Condemned livers a problem
very rarely - severe hepatitis
What is the pathogenesis of A suum in the lungs?
emphysema - heaves or thumps
may allow entrance of secondary bact or viral infections
other mammals can be infected - sheep, cattle, poultry, zoonotic
What is the pathogenesis of a. suum of adult worms?
subclinical effects
performance problems like weight gain, days to market
Obstruction, perforation of gut wall
occlude bile duct
Control - ascarids are susceptible to anthelmitics, keep barn as clean as possible
What are the essentials of ascarus suum?
common in pig barns world wide
direcct life cycle\
prevalence and intensity - grower pigs
egg numbers and egg survival
zoonotic
Control? -
What is strongyloides ransomi?
distribution worldwide - warmer climates - southern USA
parasite of baby pigs still nursing
Hygiene
Morphology - same as all strongyloides you have seen so only females are parasitic. Can has male/female that feed on organic material in the enviro and can reproduce to infect the next
What is the lifecycle of S. ransomi?
typical strongyloides: homogonic and heterogonic
prenatal and teansmammary are the major routes of infection
single infection of a sow - affects 3-4 litters PPP 11days
L3 infective to next host
What is the pathogenesis of S. ransomi?
adults in gut - catarrhal enteritis = hemorrhage (75% mortality), dysentery, anemia, wasting, vomiting, permanent stunting of growth\Dx. larvaged eggs in feces
Control treat sows prior to farrowing and try and get meds into piglets. clean up enviro best you can to get rid of microenviro from the free-living worms
What is the lifecycle of oesophagostomum spp?
adults in LI. infective stage L3
Migratation route? days w/ mucosal migration PPP 40-50 days
dx. typical strongyle egg - very similar to hyostrongylus
What is the pathogenesis of oesophagostomum spp?
rarely causes clinical problems - subclinical and clinical effects L4 in mucosa (nodules)\
severe diarrhea, weight loss, epidemiology - sows
control?
What is trichuris suis?
distribution: worldwide
parasite of pigs in the grower barn
morphology - typical whipworm “lemon-shaped” egg
What is the life cycle of T-suis?
typical trichurid
eggs in feces - resilient, L1 infective inside the egg
Mucosal migration PPP 6wks
What is the pathogenesis of t. suis?
subclinical and clinical effects
catarrhal enteritis - mucoid diarrhea (blood)
anorexia, wasting, anemia
control clean as possible, dry as possible, monitor for progress
