Animal Diseases & Their Control | Biology for Grade 12 PDF Download

ANIMAL DISEASES AND THEIR CONTROL

Domesticated animals suffer from a variety of diseases. In animals, disease may be defined as a state of discomfort associated with an abnormal function of the animal body. Diseases may be caused by mutant genes (genetic diseases).  improper nutrition or pathogens. Genetically diseased animals are strictly excluded during animal breeding. Generally, animals are raised on properly balanced diets to avoid nutritional disorders and to ensure optimum performance.

Domesticated animals suffer from diseases caused by (a) viruses, (b) bacteria, (c) protozoa, (d) fungi and (e) animals, like worms. Such diseases are commonly known as infectious diseases because they are caused by pathogenic infections. Many of the infectious diseases are known as contagious diseases since they spread to healthy animals by contact with diseased animals, or with the materials that were in direct contact with the diseased animals. Some of the infectious diseases may spread to humans from the animals, e.g. anthrax.

Infections can occur through skin. digestive tract, respiratory tract, conjunctiva, urogenital tract, placenta, umbilicus and egg. It is a good policy to implement measures for the prevention of infectious diseases, some of which are as follows.

(i) Isolation of animals suffering from or suspected to be infected with an infectious disease:

(ii) Proper disposal of the waste and all materials that were in contact with the diseased animal.

(iii) Proper cleaning and disinfection of the animal house and other materials that were in contact with diseased animal.

(iv) Transfer of healthy animals to a pasture other than that used by diseased animals.

(v) Vaccination of animals.
Veterinarian Vaccinating Animals

(vi) Injection of antiserum into healthy animals whenever an epidemic is expected.

(vii) The authorities of the veterinary department should be immediately informed of cases of infectious diseases. This will allow them to initiate measures to prevent the spread of these diseases.

BACTERIAL DISEASES

Animals suffer from several bacterial diseases. For example, cattle suffer from anthrax. mastitis, pneumonia, etc. Here, anthrax is discussed in some detail.

ANTHRAX
Anthrax is caused by the bacterium, Bacillus anthracis. This disease is contagious and affects cattle, buffaloes, horse, sheep and goats ; it can also spread to human beings. In animals, anthrax spreads through contaminated feed, water and pastures.

Symptoms and diagnosis :-

In very acute cases, there is increased respiration, and blood-mixed foamy discharge from mouth, nose and anus. In such cases, the infected animals may die within minutes. But in sub-acute and chronic cases, the infected animals have high fever (up to 41.1°C), and increased pulse and respiration rates. There is discharge of black, shiny and foamy material from natural openings of animals. The infected animals die within 2 to 3 days.
The anthrax bacterium uses up the oxygen carried by the animal blood. As a result, the animals die due to a lack of oxygen.
Disease diagnosis can be confirmed by microscopic observation of the bacterium in the blood of patients, or by culturing the bacterium present in the blood on a suitable medium.

Treatment :-

In the case of human beings a suitable antibiotic like ciprofloxacin is quite effective, particularly if used in the initial stages of the disease. But in cattle, ciprofloxacin may be effective only in chronic cases. Streptopenicillin, sulphonamide, orytetracycline & Anthrax antiserum can also be used with good results. In any case, antiserum should be given to all healthy animals to protect them from the disease.
Prevention and control :-

The general measures for prevention of infectious diseases should be followed. The healthy animals should be vaccinated. Animals that have come in contact with diseased animals should be given anthrax antiserum to protect them from the disease.

VIRAL DISEASES
Animals suffer from a variety of viral diseases. For example, cattle suffer from rinderpest, foot and mouth disease, cowpox, etc.

RINDERPEST
This diseases is caused by a virus and is highly contagious. The virus is present in all the fluids and secretions from the body of diseased animals.  The disease spreads rapidly by direct contact with patient animals, through contaminated feed, water , worker and their clothes, and by flies.

Symptoms :-
Initially, the infected animal developes fever (40.0 to 42.4°C), loses appetite, develops constipation, and passes hard faeces that often are covered with blood. In the final stages of the disease, animal suffers from loose motions, and gives off offensive odour. The body temperature declines and may go down below normal. The animal usually dies in about 7 days.

Treatment :-Treatment is effective only when it is started in the initial stages of the disease. Injections of sulphamethazine sodium is often effective. Injection of rinderpest antiserum is highly effective, especially when combines with injection of sulphamethazine sodium.

Prevention :-

All the measures for prevention of infectious diseases should be implemented. It is highly desirable to vaccinate the animals against rinderpest. In 1954, a massive vaccination programme was initiated in India. This project has been highly successful, and rinderpest is not longer a dreaded disease.
Foot and Mouth Disease (F.M.D.) or Apthous Fever It is a fast spreading disease of ruminants and artiodactyla. It usually infects tetrapods viz., cow, buffalo, sheep, goat, pig etc. Although it is not a fatal disease, the milk and wool production and working capacity of the infected animals is reduced substantially. Therefore this disease is of economic importance. India suffers a great economic loss to this disease every year.
This disease is caused by the infection of Picorna virus group. Transmission of disease is mainly by contact with infected food and water. Air infected with this virus can also spread the disease. These viruses may survive even upto two years after the infected animals has been cured.

Symptoms –
 Initially there is high fever (104°C-106°C) for 1-2 day the animal stops feeding and ruminating and becomes lethargic. The infected animal suffers from stomatitis, drooping  salivation, vesicles appear on mouth, tongue, gums, feet and teats. The tongue of the animal drops out and the animal may suffer from mastitis and abortion.
The infected animal may die of heart failure. This disease is more dangerous in young cows.

Diagnosis– The disease is diagnosed by testing the vesicles and their secretion.

Treatment– There is no specific treatment of FMD. The vesicles are washed with potassium permagnate solution to prevent secondary infection. After washing some antibacterial powder an ointment is applied on wounds. During this time the infected animal should be fed on soft food. Treating the infected (diseased) animal with antipyretics and antibiotics viz., Tetracycline injection etc. is beneficial.

Preventive Measures– Healthy animals should be kept away from the infected animals. The calf should not be given the milk of infected cow. Calves should be vaccinated when they are four month old and later on booster doses should be given after consultation with doctor.

DISEASES CAUSED BY PARASITIC ANIMALS

Animals are attacked by a number of  parasitic animals, e.g., tapeworm, round worms, flukes, ticks etc.

These parasites are mainly of two types :(i) ectoparasites, and (ii) endoparasites. 

Ectoparasites live on the skin, e.g., ticks, while endoparasites live within the animal body e.g., round worm, tape worms, liver flukes, etc. Both types of parasites feed on animal fluids like blood, and interfere with their normal growth and development.
Many parasites trasmit pathogens and, thereby, help in the spread of the concerned diseases. Some of these parasites, e.g., tapeworm. also infect human beings.

Ascaris

It is an endoparasitic nematode that infects many animals, including humans. Ascaris larvae enter animal body through mouth along with contaminated feed. The larve enter into the intestine tissue, and migrate to liver. lungs, spleen, pharynx, and kidneys, and re-enter the alimentary canal via oesophagus. They caused damage to all those organs through which they pass during their migratory phase. By the time the larvae reach intestine again, they develop into adult male and female individuals. The adult nematodes cause wounds. In the intestine and interfere with animal digestion. The affected animals may show symptoms like constipation, diarrhoea and anaemia. In severe cases, the animal may even die.

The female adult of Ascaris lays numerous eggs. Which pass out along with the animal faeces. The eggs, in due course of time, hatch into larvae, which remain associated with grass. When cattle feed on these grass, the larvae enter alimentary canals of these animals.

Treatment :-

Treatment of Ascaris is based on administration of specific medicines, such as piperax, piperazine adipate, wormex, etc

DISEASES CAUSED BY PROTOZOA

Several diseases of animals are caused by protozoan parasites. Examples of such diseases are tick fever, coccidiosis, etc. Tick fever This disease is caused by several species of Babesia, a protozoan parasite, which is spread by ticks. In India, tick fever In caused mainly by Babesia bigemina. The parasite enters into red blood cells (RBCs) and destroys them.

Symptoms :- In the acute form of this diseases, animals develop high fever (41.1-41.7°C) and stop feeding. But in the chronic form of tick fever, there is irregular fever, and constipation followed by diarrhoea. A clear diagnostic feature of the disease is the presence of pear-shaped protpzoan parasite within the RBCs.

Treatment :- The infected animals are administered a suitable medication, e.g., injection of trypan blue, acaprin, or berenil. A single injection of berenil is ordinarily sufficient to cure the animal. In addition, sanitation measures and a suitable insecticide treatment are implemented to eradicate the ticks.

Prevention and control :- Tick fever can be prevented by effectively controlling the ticks. Insecticide treatments are used to eradicated ticks from animals.

Diseases Caused by Fungi Several types of diseases in animals and birds are caused by different species of fungi. Aflatoxicosis or Mycotoxicosis is one such disease which has been described below.

Aflatoxicosis This is a fungal disease which occurs due to feeding on food infected with fungus. Scientists believe that these fungi produce a toxic substance aflotoxin (mycotoxin). Therefore the disease which arises due to these toxins is called aflatoxicosis or mycotoxicosis. toxic substance aflatoxin, is produced by Aspergillus flavus and some other species of Aspergillus. These toxins are insoluble in water and are not affected by heat (heat resistant). Aflatoxin is rapidly formed by fungi in groundnuts, cotton seeds and in some other grains. Infection of fungi occurs by a sudden change in humidity and due to rain. Aflatoxicosis affects almost all the animals and birds but the young ones of ducks resulting in death of the bird or animal.

Symptoms– Animals suffering from this disease show loss of appetite, decreased growth, bloody stool, anaemia, lazyness and blindness. Animals move around themselves and develop mental disorders, hydrocoel, ascites etc. A higher death rate is seen in the affected animals.

Diagnosis– The disease can be diagnosed by microscopic examination of the fungus.

Treatment– To detoxify aflatoxin, antifungal agents like propionic acid, calcium propionate should be mixed in food and the grain should be kept in sun for 2-3 days. The diseased animal should be given liver tonic, protein and methionine.

ADDITIONAL INFORMATION

• Huskies are thick fur coated dogs and used by Eskimos to draw their sledges.

• India ranks first in milk output in world.

• Common silk is mulberry silk.

• Mulberry specially grown for silkworm is called moriculture.

• Marine animals are richer in Iodine

• Shark Liver oil and cod liver oil are very good source of vitamin A and D.

• Aquaculture is rearing and management of useful aquatic plants and animals like fishes, oyster, prawns mussel etc.

• Pisciculture is rearing, catching and management of fishes.

• Culture fishery is the raising of the fishes in tank and pond.

• Capture fishery is management of catching of fish without actually raising them.

• Broiler :-Chickens reared exclusively for meat.

• Angoora wool :- It is obtained from Angoora rabbit.

• NDRI(National Dairy Research Institute) was establised during first five year plan at Karnal (Haryana).

• Pinctada vulgaris is a common oyster for pearl culture industry in India