ANIMAL HEALTH MANAGEMENT

MEANING OF HEALTH AND DISEASE

Health is defined as a state of alertness, freedom from ill-health, accompanied by unhindered growth and productivity of an animal. If an animal’s physiological processes are functioning normally, the farm animal is described as being healthy.

 

Signs of Good Health in Farm Animals

Signs of good health in farm animals are:

1. Contentment.
2. Alertness.
3. Eating with relish and cudding by ruminants.
4. Sleek coat.
5. Pliable and elastic skin.
6. Bright eyes.
7. Pink membranes.
8. Normal body temperature.
9. Normal pulse rate.
10. Normal breathing rate.

 

Meaning of Disease

Disease can be defined as the absence of normal health due to infection (presence of pathogens in the body), nutritional deficiency and imbalance, hereditary and functional disorders as well as injuries. Disease can also be described as any disturbance in the normal life or body function of an organism, which may affect a particular organ, or the whole body and sometimes leads to reduced growth, production, or premature death of the farm animal.

 

Types of Disease

1. Peracute disease: A disease is described as peracute if it occurs and it lasts for a very short period of time and no symptoms are easily noticed.
2. Acute disease: Acute disease in a farm animal shows some noticeable symptoms and manifests maximum casualty
3. Sub-acute disease: A sub-acute disease is the type that lasts more than the acute one with more symptoms of a disease.
4. Chronic disease: A chronic disease is the type that keeps on longer, causing loss of growth and production, but not resulting to death of the animal.

 

Causes of diseases

Diseases in farm animals are caused mainly by micro-organisms called pathogens. These pathogens are:

• Viruses.
• Bacteria.
• Fungi.
• Protozoa.

Others are:

• Malnutrition or metabolic disorder.

 

Signs of disease in farm animals

There are many external signs by which a diseased animal can be identified. These

are:

1. Unthriftiness.
2. Lack of appetite.
3. Dullness.
4. Rough coat.
5. Ruffled feather in poultry.
6. Blood stains in faeces.
7. Discharge of mucus from the nostrils, anus (or vent in birds).
8. Reduced production.
9. Wasting.
10. Diarrhoea or watery stool.
11. Premature abortion.
12. Reduced or loss of weight.
13. Reduced feed and water intake.
14. Decrease in activities.
15. Discharge from mouth and eyes.
16. Increase in mortality rate.

 

TERMS USED IN ANIMAL HEALTH

1. Pests: Pests are organisms which through their feeding habits cause physical damage and / or discomfort to other organisms called hosts. Examples of pests are mites, lice, ticks, houseflies, mosquitoes, sand flies and tsetse flies.
2. Pathogens: Pathogens are microorganisms that cause diseases in farm animals. Examples of pathogens are bacteria, fungi, viruses and protozoa.
3. Vectors: Vectors are also pests which, besides causing physical damage to the hosts, transmit disease-causing organisms to farm animals. Examples of vectors are tsetse flies, ticks, mites and fleas.
4. Parasites: Parasites are a class of organisms that live on or in their hosts permanently. They establish a physiological relationship with the hosts and rely on them totally for food and protection. Examples of parasites are ticks, lice, mites, fleas, liver flukes, tapeworms and roundworms.

 

Difference between resistance and susceptibility to diseases

The difference between resistance and susceptibility to diseases is that an animal is said to be resistant to disease when it is not affected by an invading pathogenic disease-causing organism or pathogen, while the animal is said to be susceptible to disease when it is not able to ward off the effect of the invading pathogenic organism, in which case it manifests disease symptoms.

 

Economic Importance of Animal Diseases

1. The diseases bring about poor growth of animals.
2. Diseases lead to poor feed utilization by animals due to loss of appetite or anorexia.
3. Diseases bring about low yield of products.
4. Diseases in animals produce low income for farmers due to reduced quantity and quality of products and death of the animals.

 

FACTORS WHICH DETERMINE THE DEGREE OF AN ANIMAL’S RESISTANCE TO A DISEASE

The factors which determine the degree of an animal’s resistance to a disease are:

1. Development of immunity: Animals with high level of immunity is likely to be more resistant to diseases than animals with low immunity.
2. Specie of animals: Certain groups of animals are known to be more resistant to diseases than others.
3. Inoculation: Some animals which are inoculated with some kind of vaccines against certain pathogens are known to show more resistant to diseases than those that are not inoculated.
4. Level of feeding: Farm animals which are well fed with balanced diet tend to show more resistance to diseases than those that are poorly fed.
5. Age of animal: It is well known that very young and old animals are more prone to diseases because their level of resistance is very low, while matured animals show more resistance to diseases.
6. Physiological condition of the animal: Pregnant animals for example are less resistant to diseases than other categories of the same farm animals.

 

CONDITIONS THAT MAY INACTIVATE A PATHOGEN

Conditions that may inactivate or will not bring back to active life a pathogen are

1. Low temperature: The lower the temperature, the less the chances of pathogen survival
2. High temperature: High temperature around a pathogen will render it inactive or may result to the death of that pathogen.
3. Sunlight and x-rays: High level of sunlight and x-rays are known to cause the death of certain pathogens.
4. High pH medium: High level of pH medium tends to inactivate pathogens.
5. Low pH medium: Low level of pH medium is also known to inactivate pathogens.
6. Dryness or low relative humidity: Dryness is generally known to be unfavourable condition for the survival of pathogens.

 

FACTORS THAT COULD PREDISPOSE ANIMALS TO DISEASE

Factors that could predispose animals to diseases include:

1. Health status of the animal: Animals with poor health stand the risk of getting infected with diseases faster than animals with good health.
2. Nutrition: Animals which are poorly fed are easily infected with diseases than animals that are well-fed with balanced diet.
3. Sanitation: Poor or improper sanitation, including dirty environment could predispose animals to diseases.
4. Management: Poor management of the animals such as non-administration of vaccines and drugs at appropriate doses and time could predispose animals to diseases.
5. Breeds of animals: Poor breeds of animals are in position to get infected with diseases than good breeds.
6. Poor housing: This pre-disposes farm animals to diseases due to unfavourable climatic conditions like heavy rainfall and high temperature. Diseases and parasitic infestation can also break out due to poor housing.
7. Unfavourable climatic conditions: Extremes of temperature, winds, rainfall, etc do pre-dispose farm animals to diseases.

 

VIRAL DISEASES

a) Foot and Mouth Disease

Animals affected: They are cattle, sheep and goat.

Causal organism: It is caused by a virus.

Symptoms

1. Formation of blisters on the mucous membrane of the mouth and the skin; between and around the hoofs.
2. Inflammation of teats and udder.
3. Salivation.
4. Lameness.
5. Loss of weight.

Method of transmission

1. These are transmitted through infected materials like urine, faeces, milk.
2. Mechanical means by farmers.

Control

This includes isolation of infected animals and burning or burying of contaminated materials. They should also be given regular vaccination.

 

b) Rinderpest Disease or Cattle Plague

Animals affected: These are cattle, sheep and goat.

Causal organism: It is caused by virus.

Symptoms

1. High fever.
2. Weakness.
3. Difficult breathing.
4. Blood stained diarrhoea.
5. High mortality.
6. Loss of appetite and weight.

Method of transmission

Rinderpest is a contagious disease and is transmitted by

1. Contact.
2. Contaminated feed and water.
3. contaminated faeces and urine.

Control

This can be done through

1. Regular vaccination.
2. Isolation of infected animals.
3. Restriction of infected animals movement within the farm.

 

c) Newcastle disease

Animals affected are; Domestic fowl, turkey, ducks, goose and guinea fowl.

Causal organism: Newcastle disease is caused by a virus.

Symptoms

1. Respiratory symptoms include sneezing, coughing, nasal discharge and difficulty in breathing.
2. Nervous symptoms include paralysis, muscular tremor, somersaulting and cycling movements.
3. Digestive symptoms include lack of appetite and diarrhoea.

Method of Transmission

It can be transmitted through contaminated feed, water, breeds and litter.

Control

1. Vaccination.
2. Proper sanitation.
3. Disinfection of poultry buildings.
4. Burning and burying of infected birds.

 

BACTERIAL DISEASES

a) Anthrax

Animals affected: These are cattle, sheep, goat and pigs.

Causal organism: It is caused by a bacterium called Bacillus anthraxis.

Symptoms

1. High fever.
2. Depression.
3. Blood oozes from nose, mouth and anus of carcass.
4. Lack of appetite.
5. Loss of weight.
6. Staggering and sudden death of animals.

Method of transmission

This can be through contaminated feed, water, equipment and infected animals.

Control

1. Regular vaccination
2. Proper sanitation,
3. Isolation of infected animals.

 

b) Brucellosis or Contagious Abortion

Animals affected: Pigs, cattle, sheep and goat.

Causal organism: It is caused by a bacterium called Brucella abortus or Brucella spp.

Symptoms

1. High fever.
2. Diarrhoea and dysentery.
3. Posterior paralysis.
4. Wobbling gait.
5. Pre-mature abortions.
6. Still-birth.
7. Retention of the after-birth (placenta).
8. Infertility of male animal.
9. Reduction in milk production and inflammation of scrotum.
10. Inflammation of uterus (womb).

Method of transmission

This can be through contaminated feed, water and infected animals.

Control

1. Isolation of infected animals.
2. Proper sanitation.
3. Regular vaccination.

 

c) Tuberculosis

Animals affected: Cattle, poultry birds, pigs and sheep.

Causal organism

It is caused by bacterium called Mycobacterium tubercullosis.

Symptoms

1. Difficult breathing.
2. Constant coughing.
3. Loss of weight and appetite.
4. Emaciation.
5. Paled combs and wattles.
6. High mortality.
7. Milk reduction.
8. Soft and moist cough.

Method of transmission

This is through inspiration of germs, contaminated water, feed, litters and droppings.

Control

1. Regular vaccination.
2. Slaughter infected animals.
3. Proper sanitation
4. Isolation of infected animals.

 

FUNGAL DISEASES

a) Aspergilosis

Animals affected: Poultry birds, pigs and cattle.

Causal organism: It is caused by a fungus (Aspergillus fumigatus).

Symptoms

1. Difficult breathing.
2. Loss of appetite.
3. Skin irritation.
4. Respiratory disorder.
5. High body temperature.
6. Loss of weight (emaciation).
7. General unthriftiness of the animal.

Method of transmission

This can be through contaminated feed (mouldy feed), mouldy litter and contaminated incubator.

Control

1. Regular disinfection of pens and equipment.
2. Avoid the use of mouldy feed and litter.
3. Practise good sanitation and hygiene.
4. Spray with fungicides to prevent the growth of fungi spores.

 

b) Ringworm

Animals affected: These are pig, sheep, goat, cattle, rabbit.

Causal organism: It is caused by a fungus.

Symptoms

1. Lesions on the skin of farm animals.
2. Skin irritation.
3. Loss of appetite and weight.

Method of transmission

This may be through infected animals, contact with infected brushes, feeders and drinkers.

Control

1. Disinfection of all pens and equipment.
2. Infected parts of animals should be treated every two to six days with mixture of sulphur and vaseline.
3. Old scabby area can be scrapped off and iodine solution applied.

 

PROTOZOA DISEASES

a) Trypanosomiasis

Animals affected: Resistant breeds of cattle are N’Dama, Muturu and Keteku, while susceptible breeds are White Fulani, Red Bororo, Kuri Chad, Sokoto Gudali and Boran.

Causal Organism

It is caused by a protozoan called Trypanosoma spp, e.g Trypanosoma vivax, T. congolensis, T. gambiensi.

Symptoms

They are:

1. Rise in body temperature.
2. Dullness in appearance.
3. Anaemia.
4. Sleepiness.
5. Nervous disorder leading to paralysis and death.
6. Weakness.
7. Dry coat.
8. Loss of weight.
9. Loss of appetite.

Method of transmission: The disease is spread by blood-sucking tsetse fly (Glossina spp) which may suck blood from an infected animal and transmit the pathogens to a healthy animal.

Control

1. Clearing of bush around the farm in order to remove the fly’s habitat.
2. Spraying with insecticides to kill vector (tsetse fly).
3. Treatment of infected animals with drugs such as trypanosomide and antimosan.
4. Eradication of wild species or animal carriers in and around the ranch or pasture.
5. Isolating affected animals.
6. Biological control of insect vectors.

 

b) Coccidiosis

Animals affected: These are domestic fowl, turkey, duck, goose, rabbit.

Causal organism: It is caused by the protozoa (Eimera spp).

Symptoms

1. Dropping wings.
2. Loss of appetite.
3. Blood stained diarrhoea.
4. Emaciation.
5. High mortality.
6. Dullness and unthriftiness.
7. Loss of hair or acopecia (in rabbits).
8. Rough feathers.
9. Huddling (crowding together).

Control

1. Practise proper sanitation.
2. Avoid wet litters and feed.
3. Changing of litter used and general disinfection.
4. Use suitable drugs such as amprolium, nitrofurazone or sulphaquinoxaline in water.

 

c) Red Water Fever (Piroplasmosis)

Animals affected: These are sheep, goat, cattle and pig.

Causal organism

It is caused by a protozoan called Babesia spp.

Symptoms

1. Rise in body temperature.
2. Loss of appetite.
3. Diarrhoea.
4. Pale red colour of urine.
5. Emaciation and death.

Method of transmission

It is transmitted through the bite of infected animals by a vector called blue tick.

Control

1. Spray with insecticides to kill the vector of disease (blue tick).
2. Inject animals withdrugs like trypan blue, babesan or acaprin.