Oxyurids

Question 1

Oxyurids- bursate or non bursate?

Answer 1

non bursate

Question 2

Oxyurid appearance

Answer 2

esophageal bulb and long tapering tail

Question 3

Oxyuris equi host

Answer 3

equine

very host specific

Question 4

Oxyuris equi site of infection

Answer 4

primarily in large intestine occasionally large colon and cecum

Question 5

identify

Answer 5

Oxyuris equi

horse pinworm

Question 6

Life cycle of Oxyuris equi

Answer 6

1. Females migrate to cement eggs to perianal skin and hair
2. Eggs require 4‒5 d for development
3. Transmission is through ingestion of infective eggs
   * Stick to fomites

Question 7

Who is susceptible to Oxyuris equi?

Answer 7

All age groups susceptible but most common in horses under 18 months

Question 8

Oxyuris equi PPP

Answer 8

4-5 months

Question 9

Oxyuris equi Pathogenicity/Clinical Signs

Answer 9

1. Abdominal discomfort
   * Severe infection with 3rd and 4th stage larvae
2. Pruritus ani
3. Bare patches:

• Buttocks
• Tail

Question 10

Oxyurid equis eggs- how to find?

Answer 10

scotch tape method- probably will not see in fecal float

Question 11

Identify

Answer 11

Oxyuris equi

• 85 to 95 µm by 40 to 45 µm
• Ovoid, asymmetrical
• 1 Polar plug

Question 12

Who can be infected with pinworms?

Answer 12

Dogs and cats cannot get pinworms

pinworms of horses are not infective of humans

humans get the Enterobius vermicularis species