Deworming ( Control of Internal Parasites )  in Sheep & Goats

Deworming ( Control of Internal Parasites )  in Sheep & Goats

Compiled by :

 

Dr.ASHOK KUMAR VALUPADASU

Asst.Director - V&AH Dept., Govt of Telangana

Certified Livestock Advisor –Sheep (MANAGE)

8500404016 / grass2meat@gmail.com

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• Internal parasites are one of the major source of economic loss in Sheep & Goat farming.

 

• Internal parasites are the first cause of illness & death in Sheep under 1 year age

 

• External parasites are also of serious concern in Sheep & Goats. Particularly in lambs & Kids

 

• Sheep and Parasites live together. Hence Sheep is known as Museum of parasites

 

• In almost all internal parts of body, parasites can be seen located in Sheep

 

• A Chart of principle parasites & their locations in host is enclosed (Annexure)

 

• The common Internal parasites are

 

1. Helminths ( multi cellular)

 

1. Round worms                ( Nematodes)
2. Flat worms / Tapeworms ( Cestodes)
3. Flukes                          ( Trematodes )

 

2. Protozoa ( Single cell )

 

1. Coccidia
2. Giardia
3. Cryptosporidium

 

3. Nasal bots ( Explained at end of article )

 

• Symptoms of parasitic infestation ( Helminths & protozoa ) varies with species of parasite and their number … for symptoms of Nasal bots @ refer Annexure

 

• Diarrhoea
• Thick sticky nasal discharge
• loss of condition
• Anaemia
• Bottle jaw
• Poor growth
• Abortions
• lowered production
• lowered reproduction
• Mortality

 

finally resulting in poor farm productivity.

 

• Prevention is always better than cure.

 

• Periodic & strategic deworming is the best major option in prevention of internal parasites

 

• Grazing management like lower stocking rate & rotational grazing of pasture is also of concern in control of repeated infestation

Periodic & Strategic deworming

 

• Deworming
  • means giving an Anthelmintic drug
  • is known as worming or drenching also
  • is done to eliminate internal & External parasites
  • prevents further infestation

 

• Periodic Deworming : Deworming the flock on a regular basis & as per necessity. In general Sheep & Goats under open grazing , shall be treated every 60 days or as advised by local Vet

 

• Faecal test is mandatory before deworming the flock.
• Strategic Deworming : means deworming the flock as per necessity. Monitoring parasite load by periodical faecal testing @ once a month for species and for EPG count & not to wait for deworming till physical symptoms appear.

 

Drenching necessity & frequency : decided by

 

1. Faecal Egg count : If EPG is more than 500 , do deworming once in 3 months

 

1. FAMACHA ( Anaemic status)
2. 5-Point check
3. PCV of Blood
4. Larvae culture
5. Presence of proglottids in faeces

 

Planning for Drenching

 

• After assessing drenching necessity, select a suitable / specific dewormer as per faecal report

 

• Understanding dewormers and life cycle of worms is very much required by

a Vet for selecting suitable dewormer & for repetition of deworming .

 

• The general length of lifecycle of internal worms is 21-28 days under favourable Agro-climatic conditions.

 

• Dewormers are two types : Broad spectrum & Narrow spectrum

 

• Dewormers can easily be identified by their colour
• Broad spectrums are suggested in mixed infestation
• Ensure quality of available / purchased dewormer

 

• As per requirement ensure sufficient quantity (Doses) of dewormer is available/procured

 

• Dewormer dose depends on bodyweight and on worm load

 

• In case of Adults : Consider the bodyweight of heaviest Sheep/Goat of flock for deciding dose of dewormer and not the average

 

• In case of lambs / Kids of same age group : Consider the bodyweight of heaviest lamb / Kid of flock for deciding dose of dewormer.

 

• Plan to deworm all Sheep of flock above 2 months age

 

• Check expiry date

 

• Ensure to carry sufficient no. of disposable syringes ( as per dose) or working drenching gun

 

Drenching care

 

• Strictly follow the instructions of manufacturer

• Ensure empty stomach or 12 hours fasting before deworming. Hence drenching in early day hours is preferred.

 

• Keep all Sheep / Goat in tight enclosure for catching easily.

 

• All persons involved shall mask their mouth & nose with cloth /Kerchief so as to protect themselves from Nasal fly

 

• One person shall drench

 

• One person shall restrain Sheep /Goats for facilitating ease of drench and to ensure not to choke

 

Step wise procedure to be followed as explained below

 

1. Restrain the sheep

 

1. Open the mouth.

 

1. Slightly raise the head (as shown in pic )

 

1. Make the syringe ready

 

1. Put syringe in to side of the mouth toward the left side and place the syringe over the tongue’s base toward the back of the throat

 

1. Slowly push the contents to go inside smoothly

 

1. Never hold the mouth closed

 

1. Mark the drenched.One person shall keep a mark on drenched to avoid double drenching

 

1. Before letting , ensure it swallowed the dewormer

 

1. If few jumps, move with for preventing damages of the roof of it’s mouth

 

• Not to be in hurry till animal is properly drenched

 

• Administer proper /correct dose.
• Under doses are not only less effective on decreasing worm loads, but may also enhance parasite resistance to the drugs.

 

• Ensure “no double drenching”, particularly in lambs & Kids

 

• Plan to drench lambs / Kids first and Adults later

 

Post- Drenching

 

• Do not offer feed or water for 3-4 hours post drenching

 

• Check EPG on 7^th day post drenching to assess effectiveness of deworming.

 

• If not more than 80% reduction in FEC is not noticed, repeat drenching

 

• Keep proper record of faecal testing & drenching

General information

 

• Age of lamb / Kid at first deworming should be not less than 60 days

 

• As long as Sheep / Goat are in farm, keep doing Deworming as per FEC

 

• Ewes should be drenched 21-28 days prior to lambing.

 

• Always keep notice of with-drawal period in to be slaughtered S/G

 

• Do not mix untreated / new Sheep or Goats in to existing flock, without quarantine & without drenching

 

• RotateAnthelmentics / dewormersannually, not to allow Sheep / Goats develop resistance to dewormer.

 

• For prevention of Coccidiosis , Coccidiostats shall be added in Creep feed from 15^th day of age till weaning.

 

Nasal bots : O.Ovis larvae

 

 

• The adult fly is known as Sheep gadfly and Head maggot fly

 

• Adult fly deposits minute larvae around nostrils

 

• On trying to deposit minute larvae, the adult fly causes annoyance to Sheep

 

• Sheep stop feeding

 

• Sheep become restless

 

• Press their noses against the ground or against other Sheep

 

• Tries to huddle together under buildings/shelters/shade trees

 

• The deposited minute larvae crawl on the nasal mucous membrane and setup an irritation that results in an increased flow of mucus from the nose

 

• After some time, the minute larvae migrate to frontal sinus and completes their full development and becomes matured larvae

 

• The mature larvae returns back to the nasal passages & dropped to the ground.

 

• The dropped matured larvae burrow into the soil and pupate

 

• The period of pupation is 21 – 60 days depending on soil, Temp & moisture

 

• After pupation, adult flies emerge

( from the pupal stage) and crawl to the surface

 

• After reaching the surface, they become active

 

• Symptoms :

 

1. Nasal discharge: Thin and clear at first& soon it thickens and becomes discoloured due to bacterial infection

 

1. Frequent sneezing
2. Difficulty in breathing.
3. Eyes looks inflamed
4. Head is carried low.
5. grating teeth and
6. loss of appetite or interference with feeding

• Treatment :   Ivermectin  ( Macrocyclic lactone’s ) or

1. Closantel

On Post Mortem, can find matured larvae in nasal passages and in brain also