Acute infections are the result of larval penetrations of the intestinal
mucosa during the prepatent period. Diarrhea is the usual clinical sign in these cases and
may be accompanied by weight loss and submandibular edema ("bottle jaw") in
Chronic oesophagostomosis is most common in sheep and is due to repeated
infections. Intermittent diarrhea accompanied by loss of appetite are the usual clinical
signs and in more severe chronic cases sheep may become emaciated and anemic.
Infections in pigs may produce a range of clinical signs including acute
diarrhea and a syndrome in adult females called the "thin sow syndrome" - a
chronic infection with periodic acute flare-ups due to the resumption of development
of hypobiotic larvae during spring farrowing. This syndrome shows as weight loss after
farrowing and reduced milk production with adverse effects on the growth of litters.
In acute infections clinical signs will occur during the prepatent period
and diarrhea will occur without strongyle-type eggs being seen in the feces of infected
animals. In chronic infections, strongyle-type eggs will be commonly seen but are
indistinguishable from eggs produced by other strongyle nematodes. Necropsies will show
the classic nodular lesions throughout the small and large intestines
Growing pigs (4-5 months old) with acute diarrhea due to a
prepatent infection with Oesophagostomum dentatum
|Strongyle-type eggs from a patent experimental infection with Oesophagostomum
dentatum in pigs.