Roundworms

Toxocariasis

Infection of roundworms

Dog Roundworm

Toxocara canis

Cat Roundworm

Toxocara cati

True or False: Toxocara cati is the arrowhead worm.

TRUE

What is the diagnostic stage of roundworm?

Unembryonated egg

What is the infective stage of roundworm?

Larvated egg with L3

Routes of Transmission of roundworm

• Ingestion of eggs with L3

• Paramedic hosts with L3

  • Prenatal and/or lactogenic transmission of L3

How long are eggs in the environment before becoming infective?

>2 weeks

What is the prepatent period of roundworm?

30-39days

True or False: Roundworms go through hepato-pulmonary-tracheal migration in dogs older than 3 months.

FALSE. It occurs in dogs less than 3 months old. In older dogs it is hepato-tracheal-somatic migration.

True or False: Egg shedding is rare in adults.

TRUE

For transplacental or lactogenic transmission of roundworm in dogs, what is the prepatent period?

21-25 days

What is the prepatent period of Toxocara cati?

Ingestion: 6-8 weeks

Paratenic Host: 3 weeks

Lactogenic: 3 weeksT

True or False: there is prenatal transmission of Toxocara cati

FALSE

Where do adult worms live?

Intestinal lumen

Clinical Signs of Toxocara spp. infections

• Mucoid enteritis

• Impaction

• Intusseception

• Septic peritonitis

• Malnourishment

• Dermatitis

Treatment of Toxocara

• Pyrantel Pamoate (puppies)

• Broad-spectrum control at 8 weeks (Adults)

Visceral Larva Migrans

Larvae of Toxocara migrate through different organs than what they are normally in

Ocular Larva Migrans

Common in children where Toxocara larva enter the eye and scars the retina

Toxocara Leonina

Infects dogs & cats and their wild counterparts

Infective stage of Toxocara leonine

1 week

Prepatent period of Toxascaris leonina

2-2.5 months

True or False: Toxascaris leonina undergoes mucosal migration and therefore there is NO prenatal infection.

TRUE

Baylisascaris procyonis

Raccoon roundworm that can also infect dogs

What animals are resistant to Baylisascaris procyonis?

• Opossums

• Skunks

• Cats

• Swine

• Sheep

• Goats

Neural larva Migrans

Larval migration of Baylisascaris procyonis to the CNS that causes severe debilitation and death