Good management is built on the foundation of basically sound units and buildings, not only will poultry diseases be far less likely to occur but, in addition, productivity can be enhanced at all stages.

Poultry Diseases and Disease Prevention

The disease is any deviation from the normal physiological state of health. It is always better to prevent a disease than to cure it. It is necessary to aim at disease prevention by planning a disease control program with a veterinarian. Poultry birds should be vaccinated against prevalent diseases.

It is essential to maintain strict sanitation practices by cleaning the poultry house and surroundings regularly. Prevent birds, personnel, vehicles, and stray birds from entering the farm unless disinfection is properly carried out. Where there is an outbreak of disease immediately contact a veterinarian

Diseases of Poultry

Diseases of poultry can be broadly classified into:

a) Pathogenic Diseases

These are diseases brought about by the presence of one or more pathogenic or causative organisms.

b) Management Diseases

Bad management can be caused by the pathogenic invasion and can also cause diseases directly e.g. overcrowding can lead to rapid transfer of disease from sick animals to healthy ones. It can also cause inadequate access to feed and water. Other examples of poor or bad management that can lead directly to diseases are:

Failure to vaccinate at the right time.
Failure to remove dead birds promptly.
Poor or old litter.
Failure to remove droppings regularly
Overcrowding
Poor ventilation
Poor incubation hygiene
Uncontrolled access to poultry farms and lack of foot baths
Indiscriminate transfer and mixing of eggs, stock and poultry equipment.

c) Deficiency Diseases

These are diseases caused by a lack of one or more essential nutrients needed for growth and development in the body.

d) Metabolic Diseases

These are a group of diseases that are caused by a faulty metabolic process in the body. This is caused by the absence in the body of certain fat-carrying substances resulting in the accumulation of fat in the liver, intestines, gizzard, kidneys, and heart.

Poultry Disease Prevention

The following precautions can be taken by poultry keepers to prevent the spread of diseases.

The setting and management of poultry houses: this is very important in any disease control program. It is necessary to ensure that birds of different ages are not kept in close proximity, this is to prevent diseases from spreading from older birds to younger ones.
The poultry house should be thoroughly clean and disinfected and a gap of at least 2 weeks allowed before bringing in a new batch of birds.
Sick birds should also be removed promptly to prevent them from becoming a source of infection to other birds.
Dead birds should be buried or incinerated.
Control by vaccination: Birds should be vaccinated against common diseases in a locality.
Control by Chemotherapy or prophylaxis: Another way of preventing diseases is by the use of good management associated with prophylactics such as Coccidiostats and sulpha drugs.

Table: The most important vaccinations against common diseases in the tropics:

Disease	Vaccination	Age of bird
New Castle	Intraocular Lasota Komarov	Day old 3-4 weeks 6 weeks
Mareks disease (infectious bronchitis)	MD-Vaccine IB- Vaccine Via water Or Intra occular	Day old 7-10ddays *2-3 weeks again 24 weeks
Infectious bursal disease (Gumboro) (IBD)	Gumboro vaccine	10-14 days 5 weeks
Fowl pox	Chicken N.P.X Fowl pox vaccine poxine and poxinet Re- Vaccinate	Day old 3 weeks 12-14 weeks
Fowl typhoid	fowl typhoid vaccine	4 weeks
Fowl cholera	Fowl cholera vaccine Repeat	12 weeks again 17 weeks

* Broilers * MD Marek’s disease

* Pullets * IB Infectious Bronchitis

Common Diseases of Chicken

Table: Common diseases of Chickens

Name	Means of Transmission	Causative Organism	Signs	Prophylaxis	Treatment
New Castle Disease	Bird to bird by droplet in air	Virus Bacterium.	Paralysis difficulty in breathing greenish diarrhea	Vaccination either dead or live vaccine	None
Infectious bronchitis Fowl cholera or pasteurellosis	Bird to bird Through water and food to nose and mouth	Respiratory problems large decrease in egg production. Severe diarrhea Blue combs and wattles reduction in food intake	Vaccination Annual vaccination with a live vaccine	Antibiotics to control secondary infections Remove, slaughter, and destroy infected birds. Clean infected premises

Names	Means of Transmission	Causative organism	Sings	Prophylaxis	Treatment
Marek’s disease and leukosis Fowl pox	Bird to bird Mosquitoes and other biting insects and through	. Virus Virus	Affected birds are 12- 24 weeks old. Causes paralysis and death of 10- 30% of flock Scabs on the comb, wattles,	Vaccination Isolation Vaccination Isolation	None Cull clinically affected birds. Vaccinate uninfected

Gumboro disease (infectious bursitis) Pullorum disease Name of Disease	damaged skin By direct contact especially in young birds From hen to chick through egg Means of transmission	Virus Salmonel la bacterium Causative organism	eyelids Death Prostration of birds Diarrhoea High death rate in chicks. White diarrhea Signs	Isolation vaccines are available Adult carriers should be removed Prophylaxis	ones. None Sulphur drugs or furazolidone Treatment
Coccidiosis	From the droppings of infected birds	Protozoa of infected eimeria spp	Watery and bloody diarrhea High death rate	Feed coccidiostat t Separate young and adults	Sulphonamides, pyrimidine, or prolium in water

In conclusion, diseases of poultry can be broadly classified into pathogenic, management, deficiency, and metabolic diseases, their control, and prevention are of paramount importance to ensure both maximum profitability and productivity.

It is always better to prevent a disease than to cure it, this is done through good management practice, strict sanitation, adequate nutrition vaccination against prevalent diseases, prompt removal of dead and sick birds,

The common diseases of poultry in the tropics include New castle disease, Infectious bronchitis, Fowl cholera, Mareks disease, Fowl pox, Gumboro disease, pullorum disease, and coccidiosis.