Parasitology Flashcards
What is the common name for nematodes?
Roundworms
What is the common name of cestodes?
Tapeworms
What is the common name for trematodes?
Flukes
Describe the life cycle of Toxocara spp.
The larval stage develops within the eggs. The second stage is the infective stage for this parasite. The eggs are ingested by a host, they hatch in the small intestine, penetrate the mucosa, migrate through the liver, pass through the heart and move into the lungs. They develop within a short period in the lungs. Larvae are then coughed up and swallowed and they mature into the adult stage in the small intestine.
Which of the nematodes can be transmitted via transplacental or transmammary infection?
Ascarids and hookworms
What is the scientific name of the canine hookworm?
Ancylostoma caninum
Describe the life cycle of Ancylostoma spp.
underdeveloped eggs pass into the environment, develop and hatch, releasing first stage larvae that undergo a free living existence until they develop into infective third stage larvae. they can establish themselves in a host after ingestion but the usual mode of infection is skin penetration. after penetration, they enter the venous circulation, going to the lungs to develop for a short time. They’re then coughed up, swallowed, and mature in the small intestine.
what zoonotic condition is caused in humans by Ancylostoma spp.?
cutaneous larva migrans
What is the scientific name for intestinal threadworms?
Strongyloides stercoralis
Describe the life cycle of Strongyloides stercoralis.
The nematodes give birth to eggs that will hatch into first stage larvae within the host. Depending on the chromosome number, the larvae will either develop into an infective third stage larvae that must find a new host, or they will become a free living male or female stage that will breed and produce eggs that will develop into an infective third stage. The infective third stage is capable of infection via ingestion, but the primary mode of infection is skin penetration. The larvae penetrate the skin, penetrate venous circulation, move to the lungs to develop for a short while and then are coughed up and swallowed before penetrating the mucosa of the small intestine.
What is the scientific name of the whipworm of dogs, foxes and coyotes?
Trichuris vulpis
describe the life cycle of Trichuris vulpis
The larvae develop within the eggs to the infective second stage. The eggs are ingested and the larvae are released in the intestine, which they then penetrate. Larvae develop within 8 to 10 days, return to the lumen of the intestine, migrate to the cecum, and bury their anterior ends into the mucosa. they mature into the adult stage.
True or False: pinworms are never parasites of carnivores.
True
Name some of the most commonly found tapeworm species
Dipylidium caninum, Taenia hydatigena, Taenia pisiformis, Taenia ovis, Taenia krabbei, Multiceps serialis, Echinococcus granulosis, Echinococcus multilocularis
What is the intermediate host of Dipylidium caninum?
the flea
What are the intermediate hosts of Echinococcus granulosus?
ruminants and humans
What is the scientific name of the lizard poisoning fluke of cats?
Platynosomum fastosum
What is the scientific name of the salmon poisoning fluke of dogs?
Nanophyetus salmincola
What are the intestinal flukes of dogs and cats?
Alaria spp.
Name some of the species responsible for coccidial infection in dogs and cats.
Isospora, Cryptosporidium and Sarcocystis. The cat is the definitive host for Toxoplasma gondii
Describe the life cycle of Isospora spp.
an oocyst in the feces must sporulate into the infective form. It is then ingested and the oocyst and sporocyst walls are digested in the intestine and the sporozoites are released to penetrate the intestinal epithelium and enter a cell to develop further. it undergoes asexual reproduction called schizogony, creating a large structure called a schizont that is filled with merozoites. The schizont ruptures and releases the merozoites. the next step is species specific but usually the merozoites move farther down the intestine, penetrate a cell and repeat schizogony. when the merozoites are released, they penetrate a cell and become a macrogamete (ova) or microgamete (sperm). after fertilization, the oocyst is produced again and passes in the feces
describe the life cycle of Cryptosporidium spp.
an oocyst in the feces must sporulate into the infective form. It is then ingested and the oocyst and sporocyst walls are digested in the intestine and the sporozoites are released to penetrate the intestinal epithelium and enter a cell to develop further. it undergoes asexual reproduction called schizogony, creating a large structure called a schizont that is filled with merozoites. The schizont ruptures and releases the merozoites. the next step is species specific but usually the merozoites move farther down the intestine, penetrate a cell and repeat schizogony. when the merozoites are released, they penetrate a cell and become a macrogamete (ova) or microgamete (sperm). after fertilization, the oocyst is produced again and passes in the feces
What is the scientific name of the canine heartworm?
Dirofilaria immitis
What kind of parasite is Dirofilaria immitis?
nematode
Where does Dirofilaria immitis reside in an infected dog?
the right ventricle and pulmonary arteries
What is the intermediate host of Dirofilaria immitis?
the mosquito
What is the scientific name of the stomach bot of horses?
Gasterophilus spp.
Which nematodes are responsible for the skin lesions known as “summer sores”?
Habronema and Draschia spp.
What is the scientific name of the ascarid of horses?
Parascaris equorum
What is the scientific name of the intestinal threadworm of horses?
Strongyloides westeri
What is the scientific name of the pinworm of horses?
Oxyuris equi
What is the scientific name of the liver fluke of ruminants?
Fasciola hepatica
What is the intermediate host of Fasciola hepatica?
the snail
What genus do all species of ruminant coccidia belong to?
Eimeria
What is the scientific name of the swine ascarid?
Ascaris suum
How do pigs become infected with Trichinella spiralis?
They ingest the infective larval stages in undercooked meat. The larvae mature into adults, give birth to larvae, the larvae enter the bloodstream and eventually end up in the pig’s musculature.
What is the scientific name of the whipworm of swine?
Trichuris suis
What is the order of biting and sucking lice respectively?
biting - Mallophaga
sucking - Anoplura
What are the scientific names of the botflies of horses?
Gaterophilus intestinalis, gasterophilus nasalis and Gasterophilus hemorrhoidalis
Which parasite is responsible for causing warbles in cattle?
Hypoderma spp.
What is the scientific name of the sheep nasal botfly?
Oestrus ovis
What is the scientific name of the most common flea of dogs and cats?
Ctenocephalides felis
