Nematodes

Question 1

What symptoms are most commonly seen with Toxocara spp. infections? What animals are most affected?

Answer 1

GI upset –> vomiting, diarrhea; may see worms within feces or vomit

puppies/kittens - more severe symptoms, like difficulty gaining weight, unthriftiness, and pot-bellied appearance

Question 2

How do Toxocara spp. move within their host? What is their zoonosis like?

Answer 2

larvae migrate through the liver and lungs and are carried up the mucociliary apparatus, then are swallowed to develop within the small intestine

high zoonotic potential –> T. canis is associated with visceral larval migrans in humans

Question 3

What nematodes cause visceral/cutaneous larval migrans in humans?

Answer 3

VISCERAL = Toxocara cati

CUTANEOUS = Ancyclostoma spp.

Question 4

What is the definitive host of Toxocara canis? What are 4 ways of transmission? Diagnosed?

Answer 4

dogs - small intestine

1. transplacental/transuterine
2. ingestion of eggs with L3 larvae
3. ingestion of paratenic host
4. transmammary

fecal flotation

Question 5

What is the definitive host of Toxocara cati? What are 3 methods of transmission? Diagnosis?

Answer 5

cats - small intestine

1. ingestion of eggs with L3 larvae
2. ingestion of paratenic host
3. transmammary

fecal flotation

Question 6

What is the definitive host of Toxocara leonina? What are 2 methods of transmission? Diagnosis?

Answer 6

cats and dogs - small intestine

1. ingestion of eggs infected with L3 larvae
2. ingestion of paratenic host

fecal flotation

Question 7

How does Toxocara leonina compare to other Toxocara spp.?

Answer 7

migration outside of the GIT does not occur with T. leonina infections

Question 8

Toxocara spp. summary:

Answer 8

Question 9

What clinical signs are associated with Ancyostoma spp. infection? What animals are most severely affected?

Answer 9

• diarrhea
• anemia
• lethargy
• melena
• weight loss

puppies and kittens

Question 10

What is the zoonotic potential of Ancylostoma spp. like?

Answer 10

high - causes cutaneous larval migrans in humans

Question 11

What is the definitive host of Ancylostoma caninum? What are 5 methods of transmission? Diagnosis?

Answer 11

dogs - small intestine

1. transmammary
2. ingestion of L3
3. ingestion of paratenic host
4. transplacental infection
5. third stage larvae penetrate skin

fecal flotation

Question 12

What is the definitive host of Ancylostoma tubaeforme? What are 3 ways of transmission? Diagnosis?

Answer 12

cats - small intestine

1. ingestion of infective L3
2. skin penetration
3. ingestion of infected host

fecal flotation

Question 13

How does Ancylostoma tubaeforme compare to other species?

Answer 13

transplacental and transmammary transmission does not occur

Question 14

What is the definitive host of Ancylostoma braziliense? What are 4 methods of transmission? Diagnosis?

Answer 14

dogs and cats

1. oral ingestion of L3
2. larval penetration of skin
3. ingestion of paratenic host
4. transmammary/transplacental

fecal flotation

Question 15

Ancylostoma spp. summary:

Answer 15

Question 16

What are some clinical signs of Trichuris spp. infections? What syndrome is infection associated with?

Answer 16

• diarrhea, vomiting
• hemorrhagic feces
• tenesmus
• weight loss
• anemia
• lethargy

Pseudo-Addison’s

Question 17

What is important to note for prevention of Trichuris spp. infection?

Answer 17

eggs are very resistant and may persist up to years in the environment

Question 18

What is the definitive host of Trichuris vulpis? How is it transmitted? Diagnosed?

Answer 18

dogs - cecum

ingestion of infective L2

fecal flotation with centrifugation and high specific gravity

Question 19

Why is it difficult to diagnose Trichuris vulpis infection on fecal flotation?

Answer 19

intermittent shedding, density, and small number of eggs

Question 20

Trichuris vulpis summary:

Answer 20