Parasite Glossary & Search Guide
Common names, scientific terms, and search phrases to help you find exactly what you're looking for.
Whether you call it a 'stomach worm' or Ascaris lumbricoides, parasites go by many names. This glossary covers common names, scientific names, parasite types, and the search phrases people use most — all in one place.
Search by host
Common search phrases organized by who the parasite affects.
Dogs
Cats
Humans
Types of parasites
Understanding the categories helps narrow your search.
Nematodes (roundworms)
Cylindrical worms that live in the intestines, lungs, or tissues. Examples: roundworm, hookworm, whipworm, heartworm, pinworm, strongyloides.
Cestodes (tapeworms)
Flat, segmented worms that attach to the intestinal wall. Examples: tapeworm, Echinococcus.
Trematodes (flukes)
Flat, leaf-shaped worms that infect the liver, lungs, or blood. Examples: liver fluke.
Protozoa
Single-celled organisms that can cause serious illness. Examples: giardia, toxoplasma, cryptosporidium, babesia, Chagas disease.
Ectoparasites
Parasites that live on the outside of the host — skin, fur, or feathers. Examples: fleas, ticks, lice, mites, scabies, bedbugs.
Copepods & crustaceans
Marine parasites that attach to fish skin or gills. Examples: sea lice, gnathia, pennella.
Common names vs. scientific names
The same parasite often has multiple names. Here are the most searched.
| Common name | Scientific name | |
|---|---|---|
| Tapeworm | Taenia solium / Taenia saginata / Dipylidium caninum | View |
| Roundworm | Ascaris lumbricoides / Toxocara canis / Toxocara cati | View |
| Hookworm | Ancylostoma duodenale / Necator americanus | View |
| Pinworm / threadworm | Enterobius vermicularis | View |
| Whipworm | Trichuris trichiura / Trichuris vulpis | View |
| Heartworm | Dirofilaria immitis | View |
| Giardia / beaver fever | Giardia lamblia / Giardia intestinalis | View |
| Toxoplasma / toxo | Toxoplasma gondii | View |
| Scabies / mange | Sarcoptes scabiei | View |
| Head lice / nits | Pediculus humanus capitis | View |
| Ear mite | Otodectes cynotis | View |
| Marine ich / white spot | Cryptocaryon irritans | View |
Common misconceptions
Some parasite names are misleading — here's what they really are.
Ringworm
ViewNot a worm at all — ringworm is a fungal skin infection (tinea). The name comes from the ring-shaped rash it causes.
Heartworm
ViewDespite the name, heartworm (Dirofilaria immitis) is a nematode — a type of roundworm — transmitted by mosquitoes, not a worm that crawls to the heart.
Seaworm / fish worm
ViewOften refers to Anisakis, a nematode found in raw or undercooked fish and seafood that can infect humans.
Stomach bug
ViewOften blamed on viruses, but Giardia and Cryptosporidium are parasitic protozoa that cause identical symptoms — diarrhea, cramps, nausea.
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