Parasitology: Hookworms, Roundworms, and GI Nematodes

Comprehensive vocabulary flashcards covering canine and feline hookworms, roundworms, whipworms, and other gastrointestinal nematodes based on lecture notes.

Ancylostoma caninum

The canine hookworm, characterized by 3 pairs of teeth, a large buccal capsule, and known as the most pathogenic hookworm and a voracious blood sucker.

Lactogenic transmission

The most important route of infection for hookworms (e.g., Ancylostoma caninum) and Strongyloides stercoralis in young puppies.

Ancylostoma caninum Egg Morphology

Thin-shelled morulated eggs measuring approximately $60 imes 40 ext{ µm}$.

Cutaneous Larval Migrans (CLM)

A zoonotic condition caused by hookworm larvae penetrating human skin; Ancylostoma braziliense is the major species associated with severe CLM.

Ancylostoma tubaeforme

The feline hookworm; it utilizes oral ingestion and paratenic hosts but does not perform lactogenic transmission.

Ancylostoma braziliense

A hookworm of dogs and cats with 2 teeth in the buccal capsule, common in subtropical climates, and typically causes mild disease in hosts but severe CLM in humans.

Uncinaria stenocephala

The Northern hookworm which features cutting plates instead of teeth and prefers cooler/temperate climates.

Uncinaria stenocephala Egg Morphology

Large eggs measuring $70–90 imes 40–50 ext{ µm}$.

Toxocara canis

The canine roundworm; a large stout worm with 3 lips. Transmission is most importantly in utero (transplacental).

Pot-bellied appearance

A classic clinical sign of roundworm infection in puppies, caused by inflammation and protein leakage.

Toxocara canis Egg Morphology

Round dark eggs with a thick pitted shell and a sticky albuminous coat, measuring approximately $85 ext{ µm}$.

Visceral Larval Migrans (VLM)

A zoonotic disease where roundworm larvae (typically Toxocara canis) migrate through organs such as the liver and lungs.

Ocular Larval Migrans (OLM)

A zoonotic condition where roundworm larvae migrate to the eye, potentially causing vision loss.

Toxocara cati

The feline roundworm; features prominent cervical alae (arrow-shaped projections) and lacks in utero transmission.

Toxascaris leonina

A roundworm of dogs and cats that has no tracheal migration, no in utero transmission, and no lactogenic transmission. The egg has a smooth shell.

Baylisascaris procyonis

The raccoon roundworm; known for neurotropic larvae that cause severe CNS disease and fatal encephalitis in aberrant hosts.

Trichuris vulpis

The canine whipworm; adults live in the cecum and large intestine and possess a whip-like anterior end.

Pseudo-Addison’s Disease

A clinical presentation of Trichuris vulpis infection due to electrolyte imbalances: hyponatremia and hyperkalemia (low Na:K ratio).

Trichuris vulpis Egg Morphology

Large football-shaped eggs with symmetrical bipolar plugs, measuring approximately $90 imes 40 ext{ µm}$.

Capillaria spp.

Worms with eggs that resemble whipworms but are smaller ($65 ext{ µm}$) and have off-set/asymmetrical polar plugs.

Trichinella spiralis

The Trichina worm, which is transmitted by eating undercooked meat (swine or wild game); larvae encyst in muscle tissue.

Strongyloides stercoralis

The intestinal threadworm; it is the smallest GI nematode ($2.2 ext{ mm}$) where only females are parasitic and reproduce via parthenogenesis.

Autoinfection

A process in Strongyloides stercoralis and Ollulanus tricuspis where larvae re-infect the same host, allowing rapid accumulation of the worm burden.

Strongyloides stercoralis Diagnostic Stage

The 1st stage (rhabditiform) larvae, measuring approximately $380 ext{ µm}$, most commonly found using the Baermann technique.

Ollulanus tricuspis

The feline stomach worm; the smallest worm in the course (<1 ext{ mm}) that never leaves the host and is transmitted via ingestion of vomitus.

Physaloptera sp.

The canine/feline stomach worm; stout pinkish worms that require an indirect lifecycle with intermediate hosts like crickets or cockroaches.

Spirocerca lupi

The canine esophageal worm; it creates fibrous nodules in the esophagus, stomach, and aorta, potentially causing esophageal neoplasia or aortic aneurysms.

Spirocerca lupi Egg Morphology

Thick-shelled, larvated eggs measuring $30 imes 12 ext{ µm}$, often described as resembling a paper clip.

Acanthocheilonema reconditum

A filarial parasite of dogs, often mistaken for Dirofilaria immitis, that is generally non-pathogenic to its host.

Dirofilaria immitis

The heartworm; a parasitic nematode transmitted by mosquitoes, causing significant cardiovascular disease in dogs and other canines.

Taenia pisiformis

The common tapeworm of carnivorous mammals, especially dogs, which is transmitted through ingestion of infected rodents.

Dipylidium caninum

The cucumber tapeworm; a common intestinal parasite in dogs and cats, transmitted through fleas.

Giardia spp.

Protozoan parasites causing gastrointestinal disease in dogs and cats, often transmitted through contaminated water.

Cystoisospora spp.

Coccidian protozoa that infect the intestines of dogs, cats, and other animals, leading to diarrhea.

Echinococcus granulosus

The hydatid tapeworm; a zoonotic parasite causing cystic echinococcosis, primarily transmitted to canines through ingestion of infected intermediate hosts.

Baker's Yeast (Saccharomyces cerevisiae)

Though not a parasite, this yeast can cause opportunistic infections in immunocompromised hosts, illustrating the need for immune vigilance.

Toxoplasma gondii

A protozoan parasite known for its ability to infect a wide range of hosts and cause disease, particularly in immunocompromised and pregnant individuals.

Babesia canis

A protozoan parasite transmitted by ticks, causing canine babesiosis characterized by anemia and fever.

Anaplasma phagocytophilum

A bacterial parasite causing canine granulocytic anaplasmosis, transmitted by tick bites and resulting in fever and lethargy.

Crenosoma vulpis

The fox bronchial worm; a lung parasite of canids, causing respiratory issues.

Plasmodium spp.

The genus of protozoan parasites that cause malaria in various hosts, including some mammals.