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Dairy Farming Manual

Volume 5

Husbandry Unit 10.6

page 143

Husbandry Unit 10.6: 

Technical Notes

Note: Numbers in brackets refer to illustrations in the Extension Materials.


Parasites cause major losses of production in dairy cattle and buffalo.  There are two main groups:

- Parasites which live inside the animal, for instance worms and flukes (internal parasites);

- Parasites which live on the outside of the animal, for instance ticks and mangemites (external parasites).

Under most farm conditions animals come into contact with para-sites.  As a result most animals have parasites.

Animals that grow up normally will get some resistance to para-sites so the problem is biggest in young animals.  However, certain parasites, such as the liver-fluke, may be a problem even in older, well-fed animals.

Animals can usually live with some parasites without any clear signs of disease.  However, the presence of parasites decreases production (weight gain, milk yield, calvings).  This means economic losses for the farmers.

To keep the number of parasites as low as possible the farmer has to:

- Manage his animals well (good hygiene, satisfactory nutri-tion, pasture rotation);

- Treat animals against parasites at fixed intervals.

This will not kill all parasites present but will reduce the harm to the animals.

The variety of parasite species that can damage animals is enor-mous.  However, depending on climate, environment, animals and management practices, some kinds of parasites will normally "out-number" the others in the various cattle areas.

For the field worker it is practical to consider the many kinds of parasites in groups, and in this text the following grouping has been made:

         External parasites         Internal parasites

            Lice, Ticks,                               Roundworms, Hookworms,
            Mange mites, Flies                   Lungworms, Eyeworms,
                                                              Tapeworms, Flukes,

page 145

Extension Materials
What are the signs of parasites? (15-16)

2 There are many different signs of:
- internal parasites
- external parasites

How do parasites reproduce or move from one animal to another? (17-23)

3 Parasites can pass from one animal to another:
- directly
- through a third animal.

How can you prevent parasites and treat your animals? (24-38)

4 Consult your extension worker about:
- prevention
- treatment.


  page 146

 What are parasites?

5 Parasites are small animals which take their food from a larger animal.
Compare the sizes

Match (2 1/2 cm long)

- tick
          (Parasites outside a larger animal)
- mite

- worm
                (Parasites inside a larger animal)
- fluke


Why are parasites important for you?

6 Parasites can make your cow sick, they can carry diseases and they
 can make you lose money through lower milk production.

  page 147


Parasites in buffalo

Many parasites are common in cattle and buffalo.  Generally, however, buffalo suffer less from adverse effects.  Owing to their habit of wallowing in rivers, water channels and even dirty water, there is a high risk of snail-borne helminths.   In very dry weather, buffaloes are known to get severe attacks of sarcoptic mange.  Young buffalo calves also suffer from neoascaris vitulorum infestations.

Transmission of diseases  (8-10)

Some parasites cause serious damage by transmitting diseases from one animal to another.  This is especially true for ticks which act as transmitters of the protozoan blood diseases Babesiosis, Theileriosis and Anaplasmosis.

These diseases cause great losses of animals in many areas of the world and are the reason for the continuous efforts made to reduce the severity of tick infestations in affected areas, particularly in the tropics.

page 148

8 Parasites can carry disease from one animal to another.
9 In the same way, a mosquito can carry malaria from one person to another.


  page 149

Calves are sensitive to parasites for two main reasons:  (13-14)

- They have not yet acquired any resistance against parasites commonly found in their environment.  Cattle that have grown up in a certain area have normally developed some kind of resistance (immune response) against the parasites in the surroundings which they are constantly exposed to.  Calves (and imported, adult animals) show much stronger disease symptoms from heavy parasite infections as they have had no time to build up an immune defense.

- Calves need all the nutrients they can get for growing.  If they are fed normal rations but heavily infected by internal parasites, they cannot utilize the food given to them.  Their growth may be reduced dramatically, and they easily become victims of a pneumonia or diarrhoea that may cause their death.

page 150

11 A cow without parasites:
- produces more milk and more calves
- grows quicker.
12 Parasites cause irritation and disease and they steal food.
A cow with parasites produces less milk and fewer calves.
13 Calves with parasites gain less weight than healthy calves of the same age.
No parasites: normal weight.

Parasites: lower weight.

14 Parasites are especially dangerous for young animals.


  page 151

Signs of internal parasites  (15)

Round worms, stomach/Intestine

The signs of disease depend on the type and density of worms present.  Common signs of roundworms in the stomach or intestines are:

 - loss of appetite
 - weight loss
 - diarrhoea and/or constipation
 - anaemia (pale mucous membranes)
 - swellings under the lower jaw ("Bottle Jaw") or along   the belly
 - rough haircoat
 - general unthriftiness.

One or more of these signs may be present.

Buffalo calves especially show severe infestation of a round worm Ascaris Vitulorum.  The calves show dullness, poor appetite and colic with or without diarrhoea.  The death rate is quite high and there could be complete closure of the intestinal tract.  Secondary infection could also take place.  The animals suffering from this disease emit a butyric acid odour on their breath.
The mortality rate can be quite high depending on the worm load.

Hook worms

 Hook worms have also been reported from several buffalo producing countries.


 Common signs of disease include:
 - coughing
 - difficulty in breathing
 - reduced food intake
 - reduced milk yield.
 Young animals especially may show severe signs of disease.


 The signs of disease depend upon the severity:
 - irritation and inflammation of the eye
 - ulcers and white scars in the eye.
 The worm can sometimes be seen by a close look at the eye.

page 152


 The signs of disease vary with the age and condition of the animal and the density of flukes present.  Very often the signs are confused with signs of low nutrition or wrong management. 

Signs include:

 - poor appetite and resulting loss of weight and production
 - rough haircoat
 - pot-belly.

 Diarrhoea or constipation may also be present.

 If animals are attacked by many flukes, more severe signs of disease, and in some cases even sudden deaths, may be seen.  This, however, only happens rarely.


 A large amount of rumenfluke larvae can sometimes cause diarrhoea and unthriftiness in young animals.  Normally, however, the presence of rumenflukes causes no signs of disease in cattle.


 In humans tapeworms rarely cause serious signs of disease.  In cattle the cysts can be seen in the meat after slaughtering.  They look like small bladders (about 0.5 cm) in the muscles of the head, the heart and in other places.


 The condition is very commonly observed, especially in young growing calves, in several buffalo raising countries.  The con-finement of animals to dirty places will increase the intensity of the disease.  Riverine buffalo suffer more from the disease.  The characteristic symptoms are enteritis with liquid faeces mixed with blood.

page 153

  What are the signs of parasites?
15 Animals with these signs may have parasites inside them:
page 154

 Signs of external parasites  (16)


 The typical signs of disease are:

 - loss of hair
 - formation of scabs and crusts
 - thick and folded skin
 - itching.

Animals which are not in good condition will show more serious signs of disease than healthy, well-fed animals.

Sarcoptic mange (buffalo)

 The disease is of frequent occurrence in Asia and South East Asia.  The incidence of the disease increases during the very dry season although sporadic cases occur throughout the year. It is caused by sarcoptes scabiei.

 The whole body may be affected but early lesions are observed on the neck, brisket, axilla and inner surface of thigh.  As the disease advances there is severe itching and scab formation.  In severe cases there is thickening of skin and fold formation.  The animal becomes very weak and young calves are known to die of mange.

 The disease is diagnosed by examination of skin scrapings.

Psoroptic mange (buffalo)

The occurrence is low as compared to sarcoptic mange.  The le-sions produced are also on limited areas of the body, mostly near the horns.


It is easy to see ticks on animals.  Common places to find ticks are on the head, ears, the base of the tail, the udder and the dewlap.  Several hundred ticks on one animal is not uncommon, but sometimes only a few are present.

Ticks can cause different kinds of disease in animals:

 - tick-borne diseases (see Unit 10.1)
 - loss of condition
 - anaemia 
 - inflammation and damage to the skin.

Buffalo rarely suffer from tick infestation.

page 155


Lice (buffalo)

A disease called Pediculosis is caused by a blood sucking louse (Haematopinus tuberculatus).  The infestation is observed almost everywhere the buffaloes are kept.  The louse measures about 3.5 mm and is easily seen moving in the sparse hair.  The eggs laid in large numbers attached to the hair are visible around the body.  In young calves the number could be very large because of the thick hair coat.

In poorly managed animals the number of lice on the skin could also be large.

Typical signs of disease are:

 - loss of condition 
 - stress and irritation
 - poor appetite

Figure 1: Biting louse (Trichdectes) 

Figure 2: Sucking lice 

(Left: Haematopinus, Centre: Linognathus, Right: Solenoptotus)

Buffalo fly

The buffalo fly causes great distress to animals.  It is found in most of the countries where buffaloes are raised.  The fly is important during the monsoon and rains.  Other than disturbing buffalo, the actual blood loss is small and other skin lesions are not produced in buffalo as observed in cattle.

Large black flies are also observed in buffalo populations.  Their number, however, is small in most of Asia and South East Asia.

Leeches (buffalo)

In Asia and South East Asia leeches of different types are known to live on buffalo populations.  Animals pick them up from ponds and other wallowing places.  Large infestations can cause dysp-noea.  Most of the leeches stick to the outside of the body and suck blood but there are certain aquatic species which stick to the pharyngeal mucosa.

page 156

16 Animals with these signs may have parasites on their bodies:

- red or damaged skin

- crusts and scabs

- itching

- loss of hair.



page 157

 Life cycle of internal parasites  (17-29)

Roundworms in the stomach and intestines

Many different kinds of roundworm live as parasites in the stom-ach and intestines of cattle.  Size, shape and effect on the animal varies.  Figure 3 shows the common life cycle of this group of worms.

Figure 3: Life cycle of roundworms in stomach/intestines

Lungworms (Dictyocaulus viviparus)

Lungworms are white threadlike worms.  They are about 1 mm thick and 6-8 mm long.

Figure 4: Life cycle of lungworms

page 158

Life cycle of eyeworms (Thelazia)

Female worms discharge larvae in the eyes of cattle.  The larvae are eaten by flies and develop into infective larvae in the fly.  The next time the fly ingests eye secretions, it deposits infec-tive larvae in the eye, where they develop into adults.

Liverflukes (Fasciola hepatica)

Liverflukes are flat and leafshaped, 2-3 cm long and about 1 cm wide.  They are grey-brown in colour.

Figure 5 : Life cycle of liverflukes

page 159


Rumenflukes (Paramphistomum)

Another kind of fluke, rumenflukes, often live in the stomachs of ruminants.  They are pearshaped, up to 1.5 cm long and have a bright red colour.


Tapeworms are long, flat worms divided into segments.  A large number of different tapeworms exist.  Adult worms live in the intestines of human beings and animals.

One kind, Moniezia-tapeworms, live in the intestines of cattle.  Normally they do not cause signs of disease.  If animals, espe-cially young stock, are not well-fed, they may show bad condition and digestive problems.  In this case a number of drugs are available for treatment.  Other kinds of tapeworms are of greater importance to people.

The Beef-tapeworm (Taenia Saginata)

The adult tapeworm lives in the intestines of people.  However, before eggs can develop into adult worms they have to pass through cattle as part of their life cycle.

Figure 6: Life cycle of tapeworms 

Segments from the tapeworms are passed out with the human faeces to the environment.  If the segments are placed in an area where cattle graze or drink, they may be taken up by the animals.

In cattle they will develop into bladders (called cysts) in the muscles.  When meat containing cysts is eaten by human beings, the cysts develop into worms in the intestine.

page 160

Parasites inside animals
17 Parasites inside your animals live in a cycle.
18 Worms can live in the intestines, the lungs, the eyes and the muscles.
Flukes can live in the liver or stomach.


19 The eggs of the worms and flukes pass out of the animal in the manure.
 20 Another animal eats the eggs with the grass and the worms or flukes grow inside this animal.
  page 161

Life cycle of external parasites  (21-23)

Mange mites

There are different kinds of mange mites which can cause disease (mange).  All are about 0.5 mm or less in size.

Life cycle

Mites live on the skin - either on the surface or burrowed down into the skin.  They lay eggs in the skin of cattle (or other animals) and the larvae hatch.

Figure 7: A Mite


Ticks attach themselves to the skin and live from sucking blood.

Figure 8: Life cycle of ticks

There are different kinds of ticks with different life cycles.  All ticks have to go through 4 stages of development (egg, larva, nymph and adult).

For some kinds of ticks the development: larvae --->nymphs ---> adults must take place on 2 or 3 different animals, instead of only one as shown.

page 162

21 Parasites on your animals also live in a cycle.
22 Mites lay eggs on the animal.
Ticks lay eggs on the ground.
23 When the eggs hatch, the parasites can move to other animals.

  page 163

Treatment and control of internal parasites  (24-37)


There are many drugs which can be used against roundworms.  Drugs which are given through the mouth and by injection are available.  All animals in the herd should be treated - including those which show no signs of disease.

In order to avoid disease, treatment against worms should be given at regular intervals.  Some other precautions can be taken by the farmer to avoid disease or make the parasite burden less serious:

 - if possible pastures should be rotated
 - animals with severe signs of disease should be isolated from the rest of the herd
 - animals should not be fed from the ground
 - overstocking should be avoided.

In buffalo, heavy infestation with Neoaseavis vitallorum is observed in very young calves (at 2 weeks of age).  First treatment is, therefore, given at 7 days of age in some areas.

page 164

24 Clean your animals, your equipment and your stables regularly.


25 Keep your animals in a shed or in a yard.
Cut and carry grass.
Keep insects away with nets.
26 Do not feed animals from the ground.
27 Do not crowd animals together.
Give each one enough area.


  page 165


Animals should be removed from the pasture during treatment.  Several drugs can be used for treatment; they can be given either through the mouth or by injection.

To avoid severe disease, animals should be treated against worms regularly.  How often deworming should take place depends on the area in which the animals are on pasture.


The veterinarian can dope the eye and if possible remove the worms with forceps.  Some drugs used against other worms are also effective.  The inflammation is treated with antibiotic eye-ointments.  In order to avoid disease the presence of flies should be reduced as much as possible.

page 166

28 Make a plan of your farm and divide the pastures into sections.


29 Move your animals from one pasture to another regularly for grazing.
Most of the parasite eggs in section 1 die before your animals come back to graze.
30 Rotation is also good for your pasture.

  page 167


There are many drugs which have effect on both adult and young flukes.  In each case, advice should be given by the local veterinarian or extension officer about choice of drug.

Regular treatment, normally twice a year, should also be given to avoid disease.

Animals should be kept away from wet areas where the snails necessary for the development of flukes may be present.  Wet areas with many snails should be drained, since snails need wet areas to survive.


A number of drugs can be used to treat the disease in man.  The cysts in animals cannot be treated.  In order to avoid disease, one should not eat raw or partly cooked meat.  In fully cooked meat the cysts will be destroyed.

page 168

31 Keep animals away from wet areas with snails which transmit flukes.
Drain wet areas with many snails.
32 Keep sick animals by themselves.
33 Give the right medicine at the right time.
Consult your extension worker or veterinarian.

  page 169

Treatment and control of external parasites  (24-37)


The local veterinarian/extension officer should advise on drugs which can be used for treatment.  Treatment is usually undertaken by dipping or washing.

Buildings and equipment should also be cleaned and disinfected, when animals are treated.

To avoid disease, sick animals should be kept isolated from healthy animals.  Clean animals and clean and dry surroundings also help to avoid disease.


Many drugs are available against ticks.  They can be applied in different ways: dipping and spraying of animals are the most common, but hand-dressing may also be used.

Lice (buffalo)

Clipping of hair, dipping and spraying are all good ways to control lice.

page 170

34 With care, you can reduce the number of parasites - but your animal may still have some.
Consult your extension worker about treatment
35 You can treat cattle for most parasites inside the body by feeding drugs, or by injection.
36 You can treat cattle for parasites on the body by spraying or dipping
37 and by clipping the hair and applying coconut oil and kerosene.


  page 171

38 Control parasites - and you and your animals will be better off.


page 172

What do you know about parasites in dairy cattle and buffalo?
    Parasites and their effect on animals
    1 Examples of parasites and sizes 
    2 Importance for:
    - disease
    - lost production
    3 Parasites as the cause of:
    - disease
    - irritation and low production 
    - poor weight gain 
    - danger for young animals 
    Signs of parasites
    1 Internal parasites 
    2 External parasites 
    Reproduction and transmission of parasites
    1 Internal parasites 
    2 External parasites 
    Prevention of parasites
    1 Hygiene 
    2 Buildings, grass cutting, fly prevention 
    3 Feeding 
    4 Avoid crowding 
    5 Rotation 
    6 Avoid wet areas 
    7 Isolation 
    8 Medication 
    Treatment for parasites
    1 Consult extension worker 
    2 Feeding, drugs and injections 
    3 Spraying and dipping 
    4 Clipping hair and applying coconut oil and kerosene 

page 173

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