The internal parasites that affect small ruminants
| 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) Teladorsagia 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 |
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 |
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 or last updated 17-Jul-2010 by Susan Schoenian. ©Copyright 2005-2010. Maryland Small Ruminant Page |
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