Nematodes (Rhabditida & Oxyurida)

Question 1

• Free living in decaying matter
• Hyperemic dermatitis of cattle, pigs, peple, horses, dogs, rodents
• Loves damp straw bedding
• Diagnosed by finding nematode larvae with the rabditiform esophagus in skin scraping

Answer 1

Rhabditis (Pelodera) strongyloides

Question 2

Rhabditis bovis anatomical location

Answer 2

Parasite of external ear canal

Question 3

Rhabditoid esophagus and a single egg in the uterus

Tiny! 250-450 x 15-20 um)

Have not found a male yet

Loves horses and people

Highly pathogenic and facultative

Answer 3

Halicephalobus gingivalis

Question 4

• Parthenogenic
• Only females are parasitic
• Lives deep in the mucosal crypts of small intestine
• Esophagus is at least 1/4 as long as the body
• Elongate shape of the esophagus is why the female is called “filariform”
• Varying degrees of illness in dogs
• Serious cases cause bronchopneumonia in puppies that look like CIRDC and severe watery diarrhea (looks like parvo)
• Often appear after giving steroid in puppies
• PPP= 1 week

Answer 4

Strongyloides stercoralis

Question 5

• Lives deep in the mucosal crypts of small intestine
• Transmission through penetration of L3 in skin or oral mucous membranes
• Can find eggs on fecal float and they are almost exclusively in foals
• Dams do not shed eggs and the source of infection is transmammary
• Foals will shed eggs in the feces 10-14d after birth
• Begin to see diarrhea on 13h day of life that also coincided with foal heat diarrhea
• Heavy infections present at 10 weeks
• Treatment with ivermectin

Answer 5

Strongyloides westeri

Question 6

• Lives deep in the mucosal crypts of small intestine
• Thought to be potentially a commensal
• Most susceptible group are kids 6 week to 6 months
• dehydration, inappetence, emaciation, weakness, cachexia, diarrhea, anemia, respiratory distress, and abnormal stools
• Fever is not a common C/S
• Treatment: Thiabendazole and ivermectin

Answer 6

Strongyloides papillosus

Question 7

• Lives deeply embedded in the small intestine (mucous membranes)
• Egg (L1) are shed in feces and develop to L3 in 2-3 days that infect through percutaneous in the skin or mucous membranes
• Shed eggs in feces 2-3 days after suckling
• In piglets the larvae arrest in the adipose tissue, In gilts the mammary glands.
• Piglets: Acute enteritis with bloody diarrhea (dysentery), rapid emaciation, anemia and stunting

Answer 7

Strongyloides ransomi

Question 8

• Adults are more commonly found in the small colon
• Very large (40-150mm long)
• Migrate to the anus and deposits her eggs, in cement on the perineum
• Egg masses can hold up to 8K-60K eggs
• Take 4-5 days to develop to the infective stage (L3), the same point at which the cement dries and flakes off
• PPP=5 months
• Severe infection with L4 and L5 may cause colitis
• Most common clinical sign is anal itching
• Treatment: Pyrantel pamoate or ivermectin

Answer 8

Oxyuris equi

Question 9

• Tiny, less than 3mm (horses)
• Gives birth to infective larvae so can result in autoinfection
• Lives in the large intestine

Answer 9

Probstmayria vivipara

Question 10

What are the pinworms of goats and sheep?

Answer 10

• Skrjabinema ovis and S. caprae
• Harmless, goats and sheep
• 8-10mm long

Question 11

• Humans and primates
• Small, 13.0 mm
• Common in white elementary-age kids
• Similar life cycle to Oxyuris equi, but eggs are infective within hours of cementing
• Suspected in kids with pruritis ani and insomnia
• Diagnosis is reached by observing the female in the act of laying her eggs or finding eggs

Answer 11

Enterobius vermicularis