Equine Helminths

Question 1

Heterobilharzia americana egg looks like

Answer 1

A mummy

-horses probs don’t shed

Question 2

Heterobilharzia americana life stages

Answer 2

1. Adults in mesenteric veins
2. Eggs hatch in water penetrate IH: aquatic snail
3. Cercariae emerge from snail and penetrate DH

Question 3

Heterobilharzia americana horse necropsy

Answer 3

Incidental: Disseminated parasitic granulomas

• liver
• large colon
• mesenteric vessels

Question 4

Equine cestodes

Answer 4

Small or LI equids
Abundant in autumn in FL
IH: mites
DX: proglottids in feces, double centr., ELISA, PCR
AUTUMN, EARLY WINTER
TX: Praziquantel, Pyrantel pamoate

Question 5

Anaplocephala perfoliata

Answer 5

Lappeted tapeworm, most pathogenic
Congregate near ileocecal valve
Half moon shaped egg w/ hexacanth embryo

Question 6

Anaplocephala magna

Answer 6

Large scolex tape, SI and jejunum
Egg is egg shaped w/hexacanth embryo
Rarely causes dz

Question 7

Paranoplocephala mamillana

Answer 7

Dwarf tape, SI, stomach

Rarely causes dz

Question 8

Trichostrongylus axei

Answer 8

Hairworm, Stomach and SI, Direct life cycle
Equids, swine, ruminants, humans
Copulatory bursa (males)