Oesophagostomum spp are a major cause of economic losses in the livestock industry because they impair weight gain and increases mortality in cattle, especially in tropical and subtropical areas.
Species recognised as pathogenic in cattle include:
- Oesophagostomum radiatum
The life cycle of Oesophagostomum spp is relatively short with a prepatent period of 4 - 6 weeks. Eggs are passed in the feces and become infective third stage larvae in a few weeks but may be longer in cold weather. Within the host intestine, the larvae penetrate the lower small intestine, cecum and colon. After 1 - 2 weeks, they reurn to the lumen as fourth-stage larvae.
Clinical signs associated with this parasite include anorexia, diarrhea and sometimes melena and weight loss. Nodules may form in the distal small intestine and large bowel. Stenosis or intussusception occasionally occurs.
Diagnosis is based on presenting clinical signs and confirmation of eggs in fecal samples.
- ↑ Oliveira MC et al (2009) Gastrointestinal nematode infection in beef cattle of different genetic groups in Brazil. Vet Parasitol 166(3-4):249-254
- ↑ Keyyu JD et al (2005) Epidemiology of gastrointestinal nematodes in cattle on traditional, small-scale dairy and large-scale dairy farms in Iringa district, Tanzania. Vet Parasitol 127(3-4):285-294
- ↑ Canul-Ku HL et al (2012) Prevalence of cattle herds with ivermectin resistant nematodes in the hot sub-humid tropics of Mexico. Vet Parasitol 183(3-4):292-298