This article offers a list of the most common parasites of dogs, both external (ectoparasites) and internal (endoparasites) parasites. 

Detail information on their biology and control (life cycle, anatomy, prevention, chemical control, etc.) 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.

Three letters summarize important characteristics of each parasite:

  • «H» to «HHHHH» indicates how harmful they are for dogs or puppies. The more H, the more harmful.
  • «F» to «FFFFF» indicates how frequent these parasites are. The more «F», the more frequent.
  • «C» to «CCCCC» indicates how contagious for humans are these parasites through direct or indirect contact with the dogs. The more «C», the more contagious, regardless of the seriousness of these dog parasites for humans: some are rather benign, other very harmful.

For a general introduction to parasites click here.


External Parasites (ectoparasites)

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

  • Fleas. HHHHH-FFFFF-CCCCC. Probably the most frequent and universal parasite of dogs worldwide, and potentially very harmful. Not dangerous for humans, but extremely annoying. Widespread resistance to several insecticides.
  • Stable flies. H-FF. Usually a minor problem for dogs, worldwide but mainly in rural regions. May transmit various diseases.
  • Mosquitoes. HH-FFF. Usually not a serious threat by themselves, but are vectors of several diseases, notable heartworms (Dirofilaria spp).
  • Bed bugs. H-FF. An increasing problem, but less for the dogs than for their owners. Worldwide.
  • Horseflies. H-FFF. Usually a minor problem for dogs, worldwide but mainly in rural regions. Their bites can be quite painful and are also vectors of various diseases.

Non-biting insects, do not suck blood

  • Houseflies. H-FFFFF. Usually a minor problem for dogs, worldwide but mainly in rural regions. Widespread resistance to several insecticides. May transmit some dog diseases.
  • Filth & nuisance flies. H-FF. Usually a minor problem for dogs, worldwide but mainly in rural regions. Locally, resistance to several insecticides.
  • Lice. HH-FF-C. Usually not a serious threat, neither for pets, nor for humans. Some species do suck blood.
  • Human bot flies, Dermatobia. HH-FF. A problem in many regions of Central and South America.
  • Screwworm flies. HHH-FFUsually not a very serious problem for dogs, unless in endemic regions in tropical and subtropical countries.

Ticks & mites

  • Ticks. HHHH-FFF-C. A considerable threat worldwide, especially in rural regions of tropical and subtropical countries. Ticks transmit many dog diseases.
  • Mites. HH-FF-CC. Occur worldwide but usually not the worse problem in dogs.

Additional information on the general features of insects, ticks, and mites is available in this site.


Internal parasites (endoparasites, worms, helminths)

Predilection sites are indicated in braquets.

Gastrointestinal roundworms (nematodes)

  • Ancylostoma spp. HHH-FFF-CC. Hookworms. (Small intestine and larva migrans). A serious threat for dogs. Worldwide, with different regional incidence for the various species.
  • Baylisascaris procyonis. H-F .The raccoon roundworm. (Small intestine and larva migrans). Not a major threat. Only in endemic regions with abundant raccoons.
  • Capillaria hepatica H-F Hairworms. (Liver). Not a major problem. Worldwide, but with different regional incidence.
  • Gnathostoma spinigerum. HH-F (Stomach and larva migrans). Usually a secondary problem in some endemic hot and humid regions. 
  • Gongylonema spp. H-F (Esophagus and stomach). Not a major threat for dogs. Worldwide, but only regionally relevant.
  • Physaloptera spp. H-(Stomach and small intestine). Usually a minor problem in endemic regions.
  • Spirocerca lupi. HHH-F (Esophagus). Can be a serious threat for dogs in endemic zones, mainly in tropical and subtropical regions.
  • Strongyloides spp. HHH-F-CC Threadworms, pinworms. (Small intestine and larva migrans). A serious threat for dogs, worldwide but especially in warm and humid rergions.
  • Toxascaris leonina. H-FF (Small intestine). Usually a minor problem, worldwide.
  • Toxocara canisHHHHH-FFFF-CCC The dog roundworm. (Small intestine and larva migrans). One of the most serious threats for dogs, especially for puppies. Worldwide and very frequent everywhere.
  • Trichuris sppHH-FF Whipworms. (Large intestine and larva migrans). Not the major problem worldwide, but occasionally serious.
  • Uncinaria stenocephala. HH-FFF-CC The fox hookworm. (Small intestine and larva migrans). A significant threat worldwide, but usually less serious than other hookworms (e.g. Ancylostoma spp).

Respiratory roundworms (nematodes)

  • Crenosoma vulpisH-F. The fox lungworm. (Trachea, bronchi, bronchioles). Usually a minor problem in the Northern Hemisphere.
  • Eucoleus spp. (=Capillaria spp). H-F. Hairworms, nasal worms. (Nasal cavities). Usually a minor issue. Worldwide, but with different regional incidence.
  • Metastrongylus elongatus (=M. apri). H-F. (Bronchi, bronchioles). Very occasionally in dogs.

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

  • Angiostrongylus vasorum. HHH-FF. The French heartworm. (Lung arteries, occasionally heart). A serious threat for dogs, mainly in endemic zones in Europe.
  • Dioctophyma renale. HH-F. The giant kidney worm. (Kidneys). Can be a significant problem in endemic zones.
  • Dirofilaria spp.  HHHHH-FFFF. Dog Heartworms. (Lung arteries, occasionally heart). A very serious threat for dogs. Worldwide, but especially in tropical and subtropical regions with abundant mosquitoes. 
  • Onchocerca lupi . H-F. (Eyes). Occasional problem in endemic regions.
  • Pearsonema spp (= Capillaria spp). H-F. Hairworms, bladder worms. (Bladder). usually a minor problem. Worldwide, with varying regional incidence.
  • Thelazia spp. H-F. Eyeworms (Eyes). Occasional problem in dogs. Worldwide but with endemic distribution.
  • Trichinella sppH-FF. (Muscle, small intestine). A minor health problem for dogs. Worldwide, but only in endemic zones, mainly in rural regions.

Flukes (trematodes, flatworms) 

  • Alaria spp. H-F. (Small intestine). Usually a minor issued for dogs. Worldwide, but only in endemic regions.
  • Dicrocoelium spp. H-FLancet flukes. (Bile ducts and gall bladder). An occasional problem for dogs. Worldwide.
  • Fasciola hepatica. HH-F. The common liver fluke. (Biliary ducts and gallbladder). Mostly an uncommon and not very threatening problem for dogs. Worldwide, but mainly in rural regions.
  • Heterobilharzia americana. HH-F. The dog Schistosome. (Mesenteric veins). An occasional problem in North America.
  • Opisthorchis felineus. H-F. The cat liver fluke. (Hepatic and biliary ducts). Very occasionally found in dogs. Worldwide but only in endemic regions.

Tapeworms (cestodes)

  • Dipylidium caninum. H-FFFFF-CCC. The flea tapeworm. (Small intestine). Usually not seriously harmful for dogs. But very frequent worldwide.
  • Echinococcus granulosus. H-FF-CCC. The hydatid worm. (In dogs, small intestine). Rather benign for dogs, but a serious threat for livestock and humans. Worldwide but mainly in rural zones of less developed regions.
  • Echinococcus multilocularis. H-F-CCC. The small fox tapeworm. (In dogs, small intestine). Rather benign for dogs, but a serious threat for livestock and humans. Worldwide but not very frequent.
  • Mesocestoides spp. HH-F. (Small intestine). Usually not a serious threat for dogs. Worldwide, but not very frequent. 
  • Taenia spp. H-FFFFF. (In dogs, small intestine). Usually not seriously harmful for dogs, but a significant problem for livestock (cysticercosis). Quite frequent worldwide.

Other

  • Linguatula serrata. H-F. Tongue worms. (Nasal cavities and pharynx). Usually a minor problem. Worldwide but rather occasional in tropical regions.

Other articles in this site

GoogleCustom Search