Summary of the most common parasites of cattle, both external (ectoparasites) and internal (endoparasites) parasites.  

Detail information on the biology and control (life cycle, anatomy, prevention, chemical control, etc.) of each species is available in specific articles in this site. To visit these specific articles click the corresponding link, navigate through the menu, or use the site map.

  • «$» to «$$$$$» indicates the magnitude of the economic damage for cattle caused by a parasite on a worldwide basis. The more «$», the higher the damage.
  • «R» to «RRRRR» indicates the magnitude of the resistance problems of these parasites to parasiticides on a worldwide basis. The more «R», the higher the risk of resistance.


External Parasites

Biting insects (hematophagous), i.e. they suck blood

  • Black flies, gnats. $-R. Local problem in endemic regions, wordlwide.
  • Fleas. $-R. Local problem in livestock kept indoors by warm and humid weather, worldwide.
  • Horn flies. $$$$-RRRR. Number one problem for range cattle, worldwide.
  • Horse flies. $. Usually not the biggest issue; mainly on cattle kept outdoors by warm weather, worldwide.
  • Midges. $. Local problem in endemic regions, worldwide.
  • Mosquitoes. $-RRR. A worldwide problem in all kind of livestock, but usually not the major issue.
  • Stable flies. $$$-R Can be a significant problem in cattle, both outdoors and indoors, particularly by warm and humid weather. Worldwide.
  • Tsetse flies. $$$$$. A tremendous problem in Africa in all livestock kept outdoors.

Non-biting insects, do not suck blood

  • Houseflies. $$-RRRRR. Can be a serious problem in dairy operations and feedlots worldwide, mainly during the warm and humid season.
  • Face flies. $. Can be a significant problem for range cattle in particular regions.
  • Filth & nuisance flies. $. Usually a secondary issue in dairy and feedlot operations in the warm and humid season.
  • Lice. $$. Very common problem worldwide, mainly in indoor operations, particularly during the cold season in regions with temperate climate.

Myiasis: The insect larvae are parasitic, not the adults

  • Human bot flies, Dermatobia. $$$. A serious problem in many regions of Central and South America.
  • Screwworm flies. $$$. A serious threat for all cattle outdoors in endemic regions in tropical and subtropical countries where it has not been yet eradicated.
  • Wohlfahrtia. $. Occasionally a problem in Mediterranean countries during summer on cattle outdoors.
  • Warble flies = cattle grubs. $$. A problem in the northern hemisphere, mainly in range and feedlot cattle during summer. 

Ticks (suck blood) & mites (don't suck blood)

  • Amblyomma ticks. $$$-R. A serious problem for cattle in tropical and subtropical regions, mainly in Latin America and Africa. 
  • Boophilus cattle ticks. $$$$$-RRRRR. Number one tick problem for all cattle in Latin America, Australia and parts of Africa.
  • Dermacentor ticks.$. Usually a minor problem for cattle.
  • Haemaphysalis ticks. $. Usually a secondary problem for cattle in parts of Asia, Africa and Europe.
  • Hyalomma ticks. $$. Can be a serious problem in some regions in Asia and Europe.
  • Ixodes ticks. $. Usually a minor problem for cattle.
  • Rhipicephalus ticks. $$$-R. A serious problem for cattle in tropical and subtropical regions in Africa.
  • Mange mites. $$. A problem worldwide in all kind of cattle, mainly in indoor operations, particularly during the cold season in regions with temperate climate.


Internal parasites (endoparasites, worms, helminths)

Gastrointestinal roundworms (nematodes)

  • Bunostomum spp. $$. Hookworms. Small intestine. Mostly in mixed infections, worldwide, mainly in warm and moist regions.
  • Cooperia spp. $$$-RRR. Small intestinal worms. Small intestine. Mostly in mixed infections, worldwide, mainly in warm and moist regions.
  • Gongylonema spp. $. Esophagus and stomach. Mostly a secondary issue. Worldwide.
  • Haemonchus spp. $$$$-RR. Barber's pole worms, red stomach worm. Stomach. Number one worm problem in cattle in warm and moist regions worldwide. Mostly in mixed infections.
  • Mecistocirrus digitatus. $. Stomach. Usually a secondary issue. Mostly in mixed infections. Worldwide, mainly in warm and moist regions worldwide.
  • Nematodirus spp. $$-R. Thread-necked worm. Small intestine. Mostly in mixed infections. Worldwide, mainly in regions with temperate climate.
  • Oesophagostomum spp. $$. Nodular worm. Large intestine. Mostly in mixed infections. Worldwide.
  • Ostertagia spp = Teladorsagia spp. $$$$$-R. Brown stomach worm. Stomach and small intestine. Number one worm problem in cattle in regions with temperate climate. Mostly in mixed infections.
  • Strongyloides spp. $$. Threadworms, pinworms. Small intestine. Mainly in warm and moist regions. Worldwide.
  • Toxocara vitulorum. $$. Small intestine. Mainly in warm and moist regions. Worldwide.
  • Trichostrongylus spp. $$-R. Hairworms. Mostly in the small intestine in mixed infections. Worldwide.
  • Trichuris spp. $. Whipworms. Large intestine. Usually a secondary issue. Worldwide.

Respiratory roundworms (nematodes)

  • Dictyocaulus spp. $$$-R. Lungworms. Trachea, bronchi and bronchioles. A serious problem worldwide, mainly in regions with temperate and cold climate.
  • Mammomonogamus spp. Larynx and nasal cavities. Mainly in Africa, usually not a serious issue.

Roundworms (nematodes) in the skin, heart and other organs

  • Onchocerca spp. $. Various organs. Worldwide, different species.
  • Parafilaria bovicola. $. Skin. Usually a secondary issue, mainly in Africa, Asia and parts of Europe.
  • Setaria spp. Peritoneal cavity. Usually a minor problem. Worldwide, different species.
  • Stephanofilaria stilesi. $. Skin. Regionally can be a problem in dairy cattle. Worldwide.
  • Thelazia spp. $. Around the eyes. Worldwide, normally a minor issue.

Flukes (trematodes, flatworms)

  • Dicrocoelium spp. $. Lancet fluke. Bile ducts and gall bladder. Worldwide, mainly in grazing cattle.
  • Eurytrema pancreaticum. $. Pancreas fluke. Pancreatic ducts. Usually a minor issue in South America, Africa and Asia.
  • Fasciola hepatica. $$$-R. Common liver fluke. Biliary ducts and gallbladder. Number one fluke problem for grazing cattle worldwide.
  • Fasciola gigantica. $$$. Tropical liver fluke. Liver tissue, biliary ducts and gallbladder. A serious problem for grazing cattle in regions with warm and moist climate.
  • Fascioloides magna. $. Giant liver fluke. Usually a minor issue in Europe and North America.
  • Paramphistomum spp. $. Rumen flukes. Stomach and small intestine. Worldwide a secondary issue.
  • Schistosoma spp. $. Blood flukes. Blood vessels. Usually a minor issue in parts of Asia and Africa.

Tapeworms (cestodes)