Also known as
Elaeophora sagitta is a parasitic nematode (roundworm) found in the heart, coronary arteries and pulmonary arteries of several ruminant species and African buffaloes in Africa. Infestation usually occurs without significant health effects in the Greater kudu, but may affect heart function in some other host species.
This roundworm was first described in 1907, found in the heart of a Bushbuck from Cameroon, and named Filaria sagitta. In 1926, it was transferred to the genus Cordophilus, and called Cordophilus sagittus. In1976, the genus Cordophilus was made a synonym of the genus Elaeophora, so this species became Elaeophora sagitta.
The adult worms are usually attached to the inner walls of the chambers and vessels of the heart, as well as the arterioles (small branches of the arteries that connect to the capillaries) of the lungs of various hosts.
These host animals include the Bushbuck, Greater kudu, bongos, nyala, common eland, and African Forest Buffalo. This species of roundworm has also been found in certain types of cattle. Lesions similar to those described in E. sagitta infestations were also found in sheep but the actual parasites were not seen.
E. sagitta has been found in ruminants in several African nations including Cameroon, Kenya, Malawi, Mozambique, the Republic of the Congo, South Africa and Swaziland.
The life cycle of E. sagitta has not been studied in detail, but the female sheds microfilariae, rather than eggs, directly into the blood stream.
Infestation rates as high as 74% and over 90% have been reported in free-ranging kudu, and about 50% of a herd of eland in Kruger National Park. A slaughterhouse survey in Swaziland showed a very low prevalence (less than 1%) of bovine hearts with lesions typical of E. sagitta infestation.
- Very few signs in cattle
Adult worms are typically found in the heart ventricles, coronary and pulmonary arteries, and occasionally the coronary veins. These worms produce bulging lesions in the vessel walls which are usually 1 to 2 cm in diameter.
The damage they cause has been associated with enlargement and dilatation of heart ventricles, thrombosis (blood clots) and myocarditis (inflammation of the heart muscle).
The degree of interference with general circulatory function has not been studied in detail. As one author stated, however, if the infested host is fleeing from a lion, only a minor difference in cardiopulmonary efficiency could determine whether or not the animal survives.
E. sagitta infestation appears to be clinically benign in greater kudu. Some fatalities in a herd of eland were attributed to E. sagitta infestation, though many of these eland were also infested with various gastrointestinal parasites.
In the Congo, E. sagitta infestation was thought to be one of the factors leading to mortality in several bongos and one African Forest Buffalo.
In cattle these parasitic worms don’t cause enough problems for stockmen to worry about preventative measures, though wild ruminants may spread them to cattle.
Cattle are generally not treated for E. sagitta infestation since there are generally no clinical signs.