Lecture 3 parasitology

Ascarids are

Roundworms

What are the four Ascarid species of small animals?

Toxocara canis, Toxocara Cati, Toxascaris leonina, Baylisascaris procyonis

The general morphology and biology of all ascards of vertebrates include

Large stout worms, dioecious, sexually dimorphic, females are larger, occupy the small intestine, feed on ingesta, develop to infective stage in the environment.

What are the main illness associated with roundworms?

Impaction/blockage.

______ are the larger gender of Toxocara Canis

Females

Toxocara Canis has a mouth with _____ lips

Three

Toxocara Canis has a _____ lifecycle where eggs are passed in feces of the definitive hose and developer from an egg to infective stage in 2-3 weeks outside of the host.

Direct

Toxocara Canis have ____ migration to reach the small intestine

Tracheal migration

_____ are much more efficient at producing eggs than hookworms

Toxocara Canis

Toxocara Canis can go into hypobiosis (arrested larvae n somatic tissues) where the can infect the puppies through _______ ______ and will do their own tracheal migration

Vertical integration

Toxocara Canis can have vertical transmission from mother to offspring, but often ____ _____ instead of lactogenic transmission

In utero

Toxocara Canis can also have a _____ _____ lifecycle where ingestion of infected larvae is done by a paratenic host and carry the eggs. The larvae hatch and encrust in somatic tissues. Rodents, prey carry infected by igesting eggs. "Bridging the ecological gap"

Facultative indirect lifecycle

Toxocara Canis also has _____ _______ immunity where patent infections are typical in puppies <3 months old.As puppies age, they have a decreasing tendency of the migrating larvae to develop to adult worms

Age associated immunity

Round worms disease is more common in ____ animals because naive animals end up with a lot of worms.

Young

Common clinical signs of roundworm disease includes the fact that worms swim upstream in the GIT and cause disruption f the intestines, Causes irritation. This results in inflammation, tissue _____, _______ (plasma protein leakage). All of this causes a pot bellied appearance.

Leakage. Hypoproteinemia

Blockage of the lumen and potential rupture of the intestine can happen in animals with roundworms because

Worms grow faster than intestinal tract

Roundworm eggs are not infectious wen they are passed because they have to

Develop into larvae

Clinical presentations of roundworm infections include

Worms in feces/vomit, emaciated, poor BCS, pot bellied appearance

You should assume that all puppies are born with ____ _____

Toxocara Canis

When/with what are puppies dewormed with?

2,4,6,8, weeks pyrantel pamoate

The goal of roundworm treatment is to treat at an interval shorter than the ____ _____ ___

Egg reappearance period

Most month ____ drugs accomplish adequate roundworm treatment/prevention

Heartworm

The feline roundworm is called

Toxocara Cati

Toxocara cati are similar to Toxocara Canis except morphologically, they have a prominent _____ _____ that looks like a broad, arrow-like projections of cuticle

Cervical alae

The life cycle of Toxocara cati is similar to Toxocara Canis except there is no ___ ____ infection and possibly no vertical transmission. However, cats are likely to be predators of rodents acting as _____ hosts. It could be that an adult cat passes roundworm eggs (rarely ever see adult dogs pass eggs).

In utero. Paratenic

Adult felines play significant roles in environmental contamination of

Toxocara cati

Adult ____ are more likely to be infected by paratenic host than ingestion of larvated eggs

Felines

Toxocara cati eggs have a sticky _____ coat which hangs onto everything in the environment

Albuminous

Treatment is cats for roundworms is the same as dogs. However, _________ is not FDA approved for cats, instead _____ is FDA approved for cats. Other drugs like ____ or ____ are also effective.

Pyrantel Pamoate. Drontal. Selemectin. Ivermectin

This species of roundworms is more common in exotic felids and less common in cats/dogs. They are nearly identical to T Canis. They do not have tracheal migration and instead ingested eggs hatch and go straight to the GIT. There is also no in utter infection or lactogenic transmission

Toxascaris leonia

_______ _____ roundworms are said to have a more northern-temperate distribution. They are common co-injectors. They divide under warmth. They have both direct and facultative indirect life cycle

Toxascaris leonia

_____ _____ is the name for raccoon roundworms

Baylisascaris procyonis

____ _____ worms are much larger than T Canis or T cati but have smaller eggs. They also occasionally show up during k9 fecal exams

Baylisascaris procyonis

Baylisascaris procyonis have a direct and ______ _______ lifecycle where larvated eggs are ingested by birds/squirrels, kids and they act as intermediate hosts. This roundworm is also _____ and migrates to the brane

Facultative indirect. Neurotropic.

Which species of roundworms has no tracheal migration, in utero infection, or lactogenic transmission in definitive hosts. However, this species has aggressive somatic migration and is neutrophil in intermediate hosts

Baylisascaris procyonis

All ascarids should be considered ______. T. Canis is most responsible for this

Zoonotic

Dogs are banned in ______ to control echinoccous- human zoonotic infection from Toxocara Canis

Iceland

Zoonotic toxocariasis can cause ____ _____ _____ where Toxocara larvae in the eye illicites an inflammatory reaction most commonly in children human males. This disease can result in permanent loss of vision through enucleation. The most common finding is a large elevated white granuloma on the retina or optic disk

Ocular Larval Migrans (OLM)

Zoonotic toxocariasis can cause ____ ____ ____ where there is somatic migration through the liver, kidney, and lungs. This typically happens in younger children 2-7 years old, presents with abdominal pain, headaches weakness, fever, pneumonia. It has low morbidity and no mortality, diagnosed by Toxocara specific IgG serologic assay.

Visceral larval migrans (VLM)

Prevention of zoonotic toxocariasis can be done by deworming puppies at _____ and monthly for the 1st year, deworming felines, remove feces from the yard and _____

2,4,6,8 weeks. Keep sandboxes covered, wash hands, clean dogs after rolling.

This species of roundworms is very zoonotic ad accidental ingestion of infective eggs from fecal lay contaminated environments results in aggressive somatic migration of large neutropic larvae. There have been 30 cases and 5 were fatal. This is diagnosed by neurological symptoms and serologic assay.

Zoonotic baylisascariasis

Baylisascariasis is zoonotic, often spread by

Raccoons feces.