Spiruroidea and Ascaridoidea

Question 1

Spirocerca lupi

Answer 1

Blood red worm, found in esophagus, can lead to aortic scarring and esophageal sarcomas; find the eggs in a fecal

Question 2

Physaloptera

Answer 2

Collar like cuticle inflations “FLYsaloptera”, found in stomach, bleeding ulcers, find eggs in feces

Question 3

Toxocara canis

Answer 3

Tracheal or somatic migration in DH, can be passed transplacental or transmammary

Question 4

How does T. canis migrate?

Answer 4

In feces as infected larvated egg, then hatches into a larva in the stomach to go to tracheal or somatic migration

Question 5

What happens in T. canis tracheal migration?

Answer 5

Larva burrow into the small intestine until the reach the portal system to the hepatic parenchyma to the caudal vena cava and then to the lungs. They break out of the capillaries, move to the alveoli, molt, and go to the trachea and pharynx. Then are swallowed and mature in the small intestine. The PPP is 30-35 days

Question 6

What happens in T. canis somatic migration?

Answer 6

Larvae burrow into the small intestine until they reach the portal system and get into the hepatic parenchyma. They go to the lungs via the caudal vena cava. They go to the heart via pulmonary veins and are spread throughout the body. They stop developing and become encysted in the tissues. They are transferred to puppies by transplacental or transmammary in the DH only. They are infective for the DH if encysted in IH tissues and eaten.

Question 7

What happens if the DH in T. canis infection eats encysted larvae?

Answer 7

The larvae undergo mucosal migration by burrowing into the stomach wall, molting twice, and re entering the lumen. They are adults when in the small intestine. PPP is 3 weeks

Question 8

What happens in transplacental migration for T. canis?

Answer 8

After day 42 of pregnancy, encysted larvae migrate by the umbilicus to the pups. They stay in the liver until the pups are born and then undergo tracheal migration. 95% of larvae go this way. PPP is 3 weeks

Question 9

What happens in transmammary migration for T. canis?

Answer 9

After day 42 of pregnancy, somatic larvae migrate to the mammary tissue. They undergo mucosal migration in the pups. 5% go this way. PPP is 3 weeks

Question 10

Toxascaris leonina

Answer 10

Infection by ingesting infective larvated eggs or encysted larvae from IH. Undergo mucosal migration. PPP is 2 months.

Question 11

If T. leonina does not have somatic migration, what other migrations does that affect?

Answer 11

Transplacental and transmammary-these do not happen.

Question 12

Toxocara cati

Answer 12

Arrowhead worm with cervical alae. Ingest infective larvated eggs that undergo tracheal migration. More common for cats to ingest encysted larvae from IH which undergo mucosal migration. Transmammary happens only when cat is infected during pregnancy. PPP is 2 months

Question 13

What are the clinical signs of ascarid infection?

Answer 13

Abdominal distension, diarrhea, malnourished

Question 14

Would heartworm preventives help protect against roundworms?

Answer 14

YES. Got that pyrantel pamoate, milbemycin oxime, or moxidectin.

Question 15

Can you reduce transp/transm of larvae?

Answer 15

Yes by administering fenbendazole until 14 days postpartum or ivermectin three times until 10 days after whelping

Question 16

Is Toxocara zoonotic?

Answer 16

Yes by Visceral Larval Migrans. Kids eat infective larvated eggs or eat undercooked meat. Larvae migrate systemically and 14% humans have titer.

Question 17

What is Toxocariasis?

Answer 17

Symptoms of the inflammatory reaction caused by the dying of larvae. VLM by them migrating to major organs. Ocular Larval Migrans by migrating to eye and causing vision loss. Covert by chronic exposure with symptoms like eosinophilia with nonspecific symptoms.

Question 18

What kills Toxocara eggs?

Answer 18

Disinfectants will NOT but 2% formalin will