Verminous haemorrhagic dermatitis (cattle)

Transmission involves fly vectors of the genus Musca, which ingest microfilariae when feeding on the skin lesions.

In Morocco, the haemorrhagic lesions are mainly seen on the belly, neck and forelimbs, where it can lead to a wide plages of subcutaneous necrosis, with swelling of the arm.

A similar disease, sometimes referred to as Cascado, occurs in Asia (Indonesia, Malaysia) and is caused by Stephanofilaria species.

Epidemiology differs among the countries in which it has been reported, and is dependent upon temperature and rainfall patterns, and the subsequent multiplication of the fly vectors.

The repartition and gravity of the skin lesions suggests that the causative agent may be slightly different from the one observed in Western Europe.