Cooperia

Cooperia spp.
Kingdom	Animalia
Phylum	Nematoda
Class	Chromadorea
Order	Rhabditida
Sub-order	Strongylida
Super-family	Trichostrongyloidea
Family	Cooperiidae
Genus	Cooperia
Species	C. punctata, C. oncophora, C. pectinata

Overview

Cooperia spp. are largely considered mild pathogens however there are a few species that are of greater veterinary importance, namely; C. punctata and C. pectinata. These species are pariste of cattle and small ruminants and most species of this genus prefer warmer climates.

Identification

Cooperia worms have a distinctive red colouration and a coiled appearance. The adults are between 5-8mm in length and males can be recognised by the presence of a dipropotionately large bursa at the anterior end. The worms have 16 gut cells and a square ended anterior in the females, containing refractile bodies. The tail end of the Cooperia species has one of two forms dependant on the species, in those like C. oncophora the tail tapers to a point where as in those resmbling C. curticei the sheath tip is finely pointed and contains refractile bodies. Eggs can usually be identified under microsscopic examination due to the almost parallel walls of the egg.

Life Cycle

Cooperia spp. have a typical trichostrongylid life cycle with the exception that they do not feed on blood. Once ingested the larvae penetrate the mucosa of the proximal third of the small intestine where they will remain into adulthood. Hyobiosis plays a major role in the life cycle of these species as with other trichostrongylids with the emergence of L4 larvae in the spring following infection the previous year. The prepatent period for infection without hypobiosis is 12 to 15 days but may be 3 - 5 months if larvae become arrested at the early L4 stage.

Epidemiology

Most species of veterinary significant can be found worldwide though they are more prevalent in areas with warmer climates.

Pathogenesis

Large parasite burdens of C. punctata and C. pectinata can cause severe diarrhoea, anorexia and emaciation without the presence of anaemia as they do not feed on the hosts blood. Other species are considered mild pathogens but will also cause poor weight gain and productivity. These species are often present as secondary pathogens after infection with more pathogenic Ostertagia and Haemonchus species.