parasitology endoparasites

This document contains key terminology and definitions related to endoparasites and their classifications, life cycles, clinical signs, and treatment options.

Endoparasite

A parasite that lives inside its host.

Ectoparasite

A parasite that lives on the outside of an animal.

Helminths

Worms found in the gastrointestinal tract, lungs, liver, and circulatory system, including nematodes and platyhelminths.

Host

An organism from which a parasite obtains nutrition or completes its lifecycle.

Definitive Host

The host of the sexual, adult stages of the parasite.

Intermediate Host

The host where the asexual or larval stages of the parasite occur.

Paratenic Host

A host where the parasite lives but does not develop or reproduce.

Operculum

A cap or lid on some parasite eggs that is where larvae emerge.

Parasitology

The study of organisms that live in or on another organism where they derive their nutrients.

Patent Period

The time in which the parasite is detectable via identification of ova or larval forms.

Prepatent Period

The time between initial infection and when the parasite is detectable.

Protozoa

Single-celled organisms with one or more membrane-bound nuclei.

Trophozoite

The vegetative form of the protozoa life cycle that can feed, move, and reproduce.

Vector

An organism or vehicle that carries disease from one animal to another.

Biological Vector

Acts as an intermediate host for a parasite.

Mechanical Vector

Transports the parasite, but the parasite does not develop.

Zoonosis

Diseases that can be transferred between animals and humans.

Commensalism

A symbiotic relationship where one organism benefits and the other is unharmed.

Mutualism

A symbiotic relationship where both organisms benefit.

Parasitism

A symbiotic relationship where one organism benefits and the other is harmed.

Cestodes

Flatworms or tapeworms categorized into Eucestoda (true tapeworms) and Cotyloda (pseudotapeworms).

Proglottids

Segments that contain eggs in tapeworms.

Scolex

The mouth part of a tapeworm.

Clinical Signs of Tapeworms

Vague signs of intestinal upset, abdominal discomfort, and possible anal irritation.

Dipylidium caninum

The most common tapeworm, also known as the flea tapeworm, found in dogs and cats.

Taenia pisiformis

The rabbit tapeworm, with rabbits and hares as intermediate hosts.

Echinococcus granulosa

Hydatid tapeworm associated with hydatid cysts, which are zoonotic.

Toxocara canis

Roundworm found in the small intestine of dogs, especially puppies and kittens.

Visceral Larval Migrans

Condition caused by Toxocara larvae migrating through human organs.

Dirofilaria immitis

Heartworm that can be found in dogs, cats, and humans.

Anaplasma marginale

Gram-negative bacteria that infects red blood cells in cattle.

Giardia spp.

Zoonotic flagellated protozoan that can cause giardiasis.

Sulfadimethoxine

An anthelmintic drug used in the treatment of coccidia.

Praziquantel

An anthelmintic drug used to treat tapeworm infections.