Dairy Farming Manual
PARASITES IN DAIRY CATTLE AND BUFFALO
Husbandry Unit 10.6:
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
|Why are parasites important and how do they
affect your animals? (5-14)
1 Parasites can make:
|What are the signs of parasites? (15-16)
2 There are many different signs of:
|How do parasites reproduce or move from one
animal to another? (17-23)
3 Parasites can pass from
|How can you prevent parasites and treat your
4 Consult your extension worker about:
| What are parasites?
Match (2 1/2 cm long)
|Why are parasites important for you?|
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.
|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.|
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.
|11 A cow without parasites:
- produces more milk and more calves
- grows quicker.
|12 Parasites cause irritation
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.
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
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
Hook worms have also been reported from several buffalo producing countries.
Common signs of disease
The signs of disease depend
upon the severity:
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.
poor appetite and resulting loss of weight and production
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.
What are the signs of parasites?
|15 Animals with these signs
may have parasites inside them:
of external parasites (16)
The typical signs of disease are:
loss of hair
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)
Buffalo rarely suffer from tick
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
Figure 1: Biting louse (Trichdectes)
Figure 2: Sucking lice
(Left: Haematopinus, Centre: Linognathus, Right: Solenoptotus)
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.
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.
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.
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
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.
|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.|
of external parasites (21-23)
There are different kinds of mange mites which can cause disease (mange). All are about 0.5 mm or less in size.
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.
|21 Parasites on your animals also live in a cycle.|
|22 Mites lay eggs on the
Ticks lay eggs on the ground.
|23 When the eggs hatch, the parasites can move to other animals.|
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
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
|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.
Do not feed animals from the ground.
|27 Do not crowd animals
Give each one enough area.
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.
|28 Make a plan
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.|
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.
|31 Keep animals
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.
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.
Clipping of hair, dipping and
spraying are all good ways to control lice.
|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.
|38 Control parasites - and you and your
animals will be better off.