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�

Dr. Pallav Shekhar

Asstt. Professor

Veterinary Medicine

Haemonchosis of small Ruminants

UNIT-6

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Haemonchosis

Large stomach worm

Twisted worm

Wire worm

Barbers pole worm

Lancet worm

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Haemonchus spp adult worm and Eggs

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Introduction

It is mainly a disease of sheep and goat

It is a blood sucking parasite of cattle, sheep and goat.

It is characterized by anaemia, anasarca, debility and pain.

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Etiology

H. Contortus- Sheep and Goat

H. placei- Cattle

H. bubalis- Buffalo

H. longistipes- Camel

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Small Ruminants

Cattle

Graze together

Cross infection

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Life cycle

Haemonchus

(1-1.25cm, red and red white)

Abomasum

Egg laying

(10,000eggs/day)

L1 stage

L2 stage

Embryonationation in environment

L3 stage

(Infective)

Ingestion by host

Ex-sheathment in the rumen

Emergence of L4 stage

Affect Abomasal gland

Adult worm emerge

EGG LAYING

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Characteristic of L3

The larvae (L3) migrate away from the faecal pellets and some may travells 90 cm within 24 hrs. But majority of them are found within 10cm of the faecal mass.

The motility of the L3 stage larva is maximum in the hot and moist condition. It is susceptible to cold and dessication.

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Pathogenesis

  • The histology and biochemical changes associated with Ostertagia spp. also occurs with Haemonchosis.
  • But the Vigorous blood sucking by the 4th larval stage (L4) and adult worm in the abomasum differentiate the pathogenesis of haemonchosis from that of Ostertagiosis

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  • As a result of daily loss of whole blood about 0.05ml blood/worm/day. There is Haemorrhagic anaemia & due to continuing loss of R.B.C and compensatory erythropoiesis there is depletion of Fe from Fe store.
  • Death of Animal occurs from blood loss or from anaemia accompanied by hypoproteinemia.

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Clinical Findings

  • Sudden Death
  • Blenched mucous membrane
  • Bottle Jaw
  • Melena
  • Recumbency

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Predisposing factor

Lush green pasture

Hot and humid climate

Low plane of nutrition

Over Crowding

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Clinical Pathology

EPG> 10,000

High pH of Abomasum

High plasma pepsinogen level and gastrin level

Low protein and Hb

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Necropsy findings

  • Presence of large no. of readily visible H. Contortus in abomasum
  • Hyperplastic gastritis
  • Hydrothorax and ascites

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Diagnosis

  • Epidemiological study and clinical signs.
  • EPG
  • Low Hb
  • Presence of barbers poles appearance of female worm as diagnostic appearance of Haemonchosis.
  • FAMACHA technique

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FAMACHA�

  • FAMACHA (FAffa MAlan CHArt) is a method whereby only certain sheep or goats in a flock are selected for treatment against wireworm (also known as barbers pole worm, Haemonchus contortus).
  • Sheep/goats are selected for treatment based on the degree of anaemia they are displaying in their mucous membranes.
  • In turn, the degree of anaemia is assessed through a colour guided chart.

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Objectives

  • Use as guide to determine which animals to treat.
  • Significantly reduces number of treatments given when compared with conventional drenching practices.
  • Should significantly decrease the rate of development of anthelmintic resistance.

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  • Since primary impact of H. contortus is anemia, one can indirectly measure parasite burden (and need for treatment) by measuring anemia.

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  • Only useful where H. contortus is the primary parasite species.

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  • Eye color chart with five colour categories
  • Compare chart with colour of mucous membranes of sheep or goat.
  • Classification into one of five
  • colour categories:
  • • 1 – not anemic
  • • 5 -- severely anemic

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Differential Diagnosis

Snake bite

Lightening strike

Enterotoxaemia

Coccidiosis

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Differential diagnosis

Ostertagia & Trichostrongylus

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Mild anaemia

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Profuse watery diarrhoea and faeces are dark green to yellow in colour

Heamonchosis

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Severe anaemia

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Dark tarry coloured faeces

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Prevention and Control

  • Closantel-

7.5-10mg/kg orally

  • Benzimidazole-

5-10mg/kg

  • Morantel (Banminth)-

5-7mg/kg

  • Late winter treatment remove Hypobiotic larva so reduces the parasite burden.
  • Alternate grazing
  • Spray of Urea soln. to kill the larvae
  • Vaccination by irradiated L3 and its sheathing fluid.
  • Self cure phenomenon.