Hook worm infection

HOOK WORM INFECTIONS

ANCYLOSTOMIASIS

Synonym: Hook worm disease

Definition

Ancylostomiasis is seen in all animals except in horses and are blood suckers causing chronic haemorrhagic anaemia.

Aetiology

  • A.caninum and A. braziliense in dog and cat
  • Bunostomum phlebotomum – cattle
  • B.trigonocephalum – sheep and goat

Pathogenesis, clinical signs and lesions

  • Infected larva released outside, penetrate the skin causing severe dermatitis
  • They may even enter through the skin of aberrant host producing a specific dermatitis ( creeping eruption)
  • The skin becomes thickened and scaly - 'Cooly's itch,water itch, ground itch'
  • The larva reach lungs through veins and break into the alveoli causing haemorrhages and secondary bacterial infection may lead on to pneumonia with fibrosis
  • Larvae are coughed up, swallowed and reach the small intestine
  • The adult hook worm have buccal tooth like structures and powerful oesophagus with which it draws bits of inflammatory mucosa into their buccal cavity damaging the epithelium and sucks blood.
  • An anticoagulant secreted causes flow of blood even after the worm changes position.
  • Bacteria may also enter through the denuded epithelium.
  • Each parasite may suck 0. 8 to 1ml of blood in 24 hours and the erythrocyte count may drop to 25 per cent of normal.
  • Anaemia is hypochromic, microcytic and hyperplasia of the haematopoietic region are seen
  • Diarrhoea with dark tarry coloured faeces
  • Hyperaemia, emaciation and weakness in chronic cases
Haemarrohagic enteritis

Haemorrhagic enteritis

Diagonsis

  • Symptoms of bottle jaw condition
  • Demonstration of eggs in faeces.
Last modified: Wednesday, 6 June 2012, 2:10 PM