Small Ruminant
Info Series

The Internal Parasites That Affect Sheep and Goats

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**Genus and species**	Common name	Site	Life cycle		Conditions	Clinical signs	Significance
Haemonchus contortis	Barberpole worm Wire worm	Abomasum	Direct	18 to 21 days	warm, moist summer rainfall	Blood loss (Anemia) Edema ("Bottle Jaw") Weakness Wool breaks Sudden death	Major problem in warm, moist climates
Ostertagia circumcincta	Medium or brown stomach worm	Abomasum	Direct	20 days	cool, moist	Production loss Lack of appetite Diarrhea Weight loss Decreased wool production	Usually secondary to Barber Pole worm in warm, moist climates
Trichostrongylus	Bankrupt worm Hair worm	Abomasum Small intestine	Direct	< 21 days	warm, moist	Black scours Reduced appetite Production loss Ocassional death	Usually secondary to Barber Pole worm in warm, moist climates
Strongyloides papillosus	Common threadworm	Small intestine	Direct	7-9 days	warm, moist	Weight loss Diarrhea Inflamation between toes	Minor
Coopera spp.	small intestinal worm	Small intestine	Direct	20 days	cool, wet winter rainfall	Loss of appetite Diarrhea Weight loss Decreased wool growth	Minor Additive
Nematodirus spp.	threadneck worm	Small intestine	Direct	20 days	cool, wet	Usually sub-clincial Diarrhea, loss of appetite, weight loss	Usually secondary to Barber Pole worm in warm, moist climates
Dictyocaulus filaria Muellerius capillaris	lungworm hair lungworm	Trachea and bronchi	Direct Indirect (snails, slugs)	5 weeks	cool, wet	Usually no signs of infection. Coughing, fluid in lungs if disease is severe. Pneumonia	Minor
Moniezia spp.	tapeworm	Small intestine	Indirect (pasture mites)	6 weeks	wet	Heavy infestations may result in unthriftiness and GI disturbances	Mostly non-pathogenic
Eimeria spp.	coccidia	Small intestine	Direct	< 21 days	cool, wet condtions Overcrowding	Liquid diarrhea Off feed, depression Death	Major
Trichuris ovis	whipworm	Caecum	Direct	6-12 weeks	Dry	Diarrhea	Of little consequence Additive
Bunostomum phlebotomum	hookworm	Small intestine	Direct	1-2 months	warm, most	Unthriftiness Diarrhea Blood loss Anemia Sore feet	Minor
Oesophagostomum	nodule worm	Large intestine	Direct	5 weeks	cool, wet winter rainfall	Damage lining of small intestines	Minor
Paralaphostrongylus tenius	meningeal worm deer worm brain worm	central nervous system	Indirect (snails, slugs)	82-91 days	cool, wet	Hindquarter weakness Ataxia Paralysis Blindness	Varies
Fasciola hepatica	liver fluke	Liver	Indirect (snails, slugs)	8-12 weeks	wet areas	production losses Death Organ condemnation	Varies

Created 20-Oct-2009 by Susan Schoenian. ©Copyright 2005. Maryland Small Ruminant Page

References:
WormBoss.com.au
Parasites and Disease - Australia Sheep Worm Control
The Merck Veterinary Manual
Parasites and Parasitic Diseases of Domestic Animals - University of Penn
NewZealand-Merial.com - Sheep Disease Information