Table of Contents

Amphistomiasis

Amphistomiasis is caused by Amphistomes (Stomach flukes or Conical flukes).

Morphology

Small, conical in shape & pink in colour.
Eggs are thin shelled, oval shape, distinct operculum with a small knob at the posterior end.

Animals are reared in extensive systems of management are more susceptible.
Animals are grazing near pond area/ other natural resources, especially during drier months are more susceptible.
The palatable grazing, concentration of cattle, snail and metacercariae over small area leading to heavy infections.
Incidence of disease is high during summer months with high rain fall.
Young animals are highly susceptible than adult.
Preinfection – give resistant.

Immature flukes embedded in mucosa of duodenum and upper ileum, plug feeder of mucosa (drawing piece of mucosa into the sucker) causes haemorrhages and necrosis.
In heavy infections it causes frank haemorrhagic dueodenitis.

Severe enteritis with enormous number of migrating flukes in the dueodenum.
Profuse persistent fetid watery diarrhoea, increased thirst and drink more water.
Marked weakness, depression, dehydration and anorexia.
Submaxillary edema with pallor of mucosa.
Anemia and hypoprtoteinemia.
Dry rough hair coat.

Subcutaneous oedema.
Accumulation of fluid in the body cavities.
Presence of large no. of flesh colour worms in the intestine (dueodenum).
Gigantocotyle explantatum- superficial haemorrhage in the bile duct and gall bladder at the attachment.
In heavy infection- liver is pale and shows some degree of fibrosis.

Based on grazing history and clinical signs.
Faecal examination.
Presence of immature worms in fluid faeces.
At post mortem-presence of large number of brownish pink parasites on intestinal mucosa.

Oxyclozanide – 18.7 mg / kg for two days (Immature & Mature – 100 % effective).
Bithionol sulphoxide – 40 mg/ kg (activity against Immature – 100%).
Resorantol – 65 mg / kg (Immature – 65% &Mature – 100%).
Niclosamide – 90 mg / kg (Immature – 99.9% &Mature – 8%).
Niclofolan – 6 mg / Kg (Immature – 96% & Mature – 43%).
Hexachlorophene – 20 mg/ kg – single dose.
Rafoxanide @7.5-10 mg/kg.
Resorantol and Oxyclozanide are the drug of choice for both immature and mature Amphistomes.

Physical – Improving drainages.
Chemical – Applying molluscicides.
Copper sulphate – 1 in 1,00,000 solution for water reservoir.
Copper sulphate powder – 10 – 35 kg / hectare, applied along with sand for easy application and Sheep are not allowed to graze until rainfall occurs.
N-tritylomorpholine – 0.45 kg/ 680 litres / hectare applied during spring or mid summer season.
Biological- rearing of ducks, geese and frog in infected water sources prey the snail.