are complications in that multiple species overlap in certain regions and double infections are common. This creates difficulties for routine mass treatment because people with onchocerciasis in particular react badly to treatment for lymphatic filariasis. Other animals Filariasis can also affect domesticated animals, such as cattle, sheep, and dogs. Cattle Verminous hemorrhagic dermatitis is a clinical disease in cattle due to Parafilaria bovicola. Intradermal onchocerciasis of cattle results in losses in leather due to Onchocerca dermata, O. ochengi, and O. dukei. O. ochengi is closely related to human O. volvulus (river blindness), sharing the same vector, and could be useful in human medicine research. Stenofilaria assamensis and others cause different diseases in Asia, in cattle and zebu. Horses "Summer bleeding" is hemorrhagic subcutaneous nodules in the head and upper forelimbs, caused by Parafilaria multipapillosa (North Africa, Southern and Eastern Europe, Asia and South America). Dogs Heart filariasis is caused by Dirofilaria immitis. See also Ascariasis Eradication of infectious diseases Helminthiasis List of parasites (human) Neglected tropical diseases References Further reading External links Page from the "Merck Veterinary Manual" on "Parafilaria multipapillosa" in horses Animal diseases Insect-borne diseases Helminthiases Tropical diseases Veterinary helminthology Parasitic diseases