Disease Polutry

Disease Polutry

Disease is a condition caused by living factors like viruses, bacteria or parasites, or non-living factors such as deficiencies, toxins and other physical or chemical agents. Diseases cause severe economic loss in poultry production. The loss is not only due to the death of birds but also due to loss in production.

Bacterial Diseases:

a. Coli-bacillosis:

It is a common bacterial disease caused by E. coli organism. Inhalation, particularly in young broilers and poults, fecal contamination, infected or contaminated eggs, wet litter problems and contaminated water are the reason for outbreak of disease. The severity of this septicaemic disease is due to a combination of factors as the virulence, exposure to aerogenic infection, the E. coli strains involved and the intensity of the predisposing. The common signs of infection include acute fatal septicaemia, air sacculitis, enlarged hyperemic liver and spleen, increased fluid in body cavities, subacute fibrinopurulent air sacculitis, pericarditis, perihepatitis, lymphocytic depletion of the bursa and thymus. Control of infection of the yolk sac depends on sanitary conditions at the hatchery and provision of appropriate warmth during brooding, practice of efficient water sanitation methods, use of clean drinkers, providing adequate ventilation and management of litter.

b. Salmonellosis: Bacillary white diarrhoea: S. pullorum Fowl Typhoid: S. gallinorum Fowl Paratyphoid: S. typhimurium

This disease is transmitted vertically from parent flocks and affects baby chicks with a high mortality. Huddling, pasting of vent feathers and whitish diarrhea are noticed. It can affect poultry, and is one of the most difficult diseases to control. Poultry can become infected with Salmonella through contact with carrier animals, such as rodents, cats, and insects, as well as contaminated feed, litter, water, and aerosol transmission. There may be no lesions due to an acute septicemia and death. Lesions in young birds usually include unabsorbed yolk sacs and classic gray nodules in the liver, spleen, lungs, heart, gizzard, and intestine. Firm, cheesy material in the ceca (cecal cores) and raised plaques in the mucosa of the lower intestine are sometimes seen. Occasionally, synovitis is prominent. Adult carriers usually have no gross lesions but may have nodular pericarditis, fibrinous peritonitis, or hemorrhagic, atrophic, regressing ovarian follicles with caseous contents. Ensuring Salmonella-free chicks from the hatchery, by using sterilized fish-meal and meat meal and pelleting of the feed will also be helpful to control disease.

c. Infectious coryza:

It is a disease which affect respiratory tract caused by Haemophilus paragallinarum. Symptoms of this disease are swollen faces and swollen eyes, filled with a cheesy substance. Respiratory distress and poor feed intake are also noticeable. This disease can be controlled by avoiding overcrowd, wet litter and by reducing the ammonia level by proper ventilation.

d. Chronic Respiratory Disease (CRD):

Infection is caused by Mycoplasma gallisepticum. Respiratory distress, sound of rales, sneezing, poor weight gain and nasal discharge are symptoms of the disease. Infected chicks transmit the disease through water and feed. Avoid overcrowding, improve ventilation, and ensure hatchery sanitation and screening of parent stock. Mixing tiamulin or tylosine in the feed will be helpful in the treatment of disease.

Viral diseases:

a. Newcastle disease (Ranikhet disease):

This is caused by paramyxo virus. The common symptoms are depression, prostration, loss of appetite, greenish/yellowish diarrhea, nervous signs like incoordination, twitching of neck etc. Mortality heavy (my reach upto 100%) in acute outbreak. Post mortem finding are pin pointed hemorrhages at the tip of proventricular glands, Hemorrhagic/ diphtheritic ulcers on the intestine and caecal tonsils. Practicing strict biosecurity measure and through considering strict vaccination schedule the disease can be controlled.

b. Avian influenza (bird flu):

• Highly Pathogenic Avian Influenza (HPAI) is highly lethal systemic disease affecting vast majority of birds. The disease is caused by the Influenza Type A virus (H5N1 causes bird flu). Because of the zoonotic as well as pandemic potential, the disease gained much public health importance.
• Water birds and migratory birds, ducks act as carriers and spread the infection. Bird flu is highly contagious among birds and also affects ducks, and turkeys. Sudden, heavy and unusual mortality reaches almost 100% without any clinical signs.
• Combs and wattles are cyanotic and oedematous, and may have petechial or ecchymotic haemorrhages at their tips. Profuse watery diarrhoea is frequently present and birds are excessively thirsty.
• Respiration may be labored, haemorrhages may occur on unfeathered areas of skin. Nervous disorders like tremors, torticollis and opisthotonus can be observed. Post mortem lesions are extremely variable depending on the severity.
• Hemorrhagic lesions (petechial to ecchymotic on all the visceral organs, serous membranes, skin and muscles in acute cases, lungs pneumonic, enteritis, air saculitis, spleenomegali are some of the common lesions.
• At disease outbreak area within one km from the site of confirmed AI will be designated as “Infected Zone”. Rest of the area within 10 km is the “Surveillance Zone”. At the infected zone the birds will be culled. Absolute ban on movement of poultry, closure of poultry and egg markets/ shops, restrict access to wild and stray-birds, restriction of movement of persons, vehicles, destruction/culling of birds in the infected zone, disposal of dead birds, destruction of infected materials, cleaning and disinfection of farm premises and farm implements (commercial and backyard Poultry), implementation of the Post Operation Surveillance Plan (POSP), declaration of freedom status and repopulation of birds in the infected zone etc. are carried out.

A planned programme for the prevention and control of diseases in the poultry houses is a crucial factor in profitable poultry farming. The following general principles are to be followed.

1. Clean the house at least two weeks before housing a new batch of birds.
2. Remove all old litter and equipment. Clean the ceiling, walls and floor. Thorough sweeping and washing followed by treatment with disinfectants are necessary.
3. Wash, disinfect and dry the equipment before placing in the house.
4. Clean the light reflectors, replace burnt out bulbs and check electric connections.
5. Keep all wild birds, rats, dogs and cats out of the farm.
6. Do not allow visitors into the poultry houses.
7. Burn or bury all dead birds immediately.
8. Clean the waters and feeders daily with 1% ammonia solution.
9. Change foot-bath at the entrance of poultry house daily.
10. Adhere to strict sanitation in and around the poultry house.
11. Remove wet litter immediately.
12. Look for signs of ill health in the flock every time you enter the poultry house.
13. Deworm the birds as and when required after peak production.
14. If any disease is suspected, immediately obtain accurate diagnosis and follow recommendations of the poultry specialist consulted.

c. Infectious Bronchitis:

Infectious bronchitis (IB) is a highly contagious viral disease that affects the respiratory tracts of chickens. It is caused by the avian infectious bronchitis virus (IBV), which belongs to the coronavirus family. IBV is a major problem for the global poultry industry, as it affects the respiratory tract, gut, kidney, and reproductive systems. IB is transmitted to the upper respiratory tract by either direct bird-to-bird contact or exposure to fomites.

Clinical Signs:

1. Respiratory signs like coughing, sneezing and rales in chicks, discharges from eyes and nostrils.

2. Reproduction signs include drop in egg production (drops by 60-90 %) and hatchability, thin shelled, rough eggs with low internal egg quality.

Postmortem Lesions:

1. Tumors (lymphomas) are present in one or more of visceral organs and tissues. Gonads (ovary), liver, spleen, lungs, kidney, skin etc. may be involved.

2. Tumours cause nodular or diffuse enlargement of the affected organ.

3. In classical form, nerves become thickened slightly or as much as 3 or 4 times the normal and becomes rounded instead of the normal.

f. Fowl pox:

A viral disease that affects poultry of all ages and breeds. It's caused by viruses of the Poxviridae family. Fowl pox is a common disease in backyard chickens that are not vaccinated. Most birds survive the infections, although very young or weak birds may be lost. The cutaneous form of fowl pox is characterized by nodular lesions on various parts of the unfeathered skin of chickens and on the head and upper neck of turkeys. In the diphtheritic form of fowl pox, lesions develop on the mucous membranes of the mouth, esophagus, pharynx, larynx, or trachea (wet pox or fowl diphtheria). Occasionally, lesions occur almost exclusively in one or more of these sites.

FUNGAL DISEASES:

Brooder Pneumonia:

Young chicks of 1-2 weeks of age are commonly affected. High mortality rate of 10-50 percent is noted, with symptoms of gasping, respiratory distress and strong thirst. Yellowish white pin-point filaments on lungs are present. This disease can be prevented by avoiding the use of mouldy, fungus-infested litter material and by using thoroughly cleaned drinkers and feeders.

Mycotoxicosis:

Caused by toxins produced by fungi in feed ingredients. Clinical signs are reduced feed intake, poor growth rate or egg production, breakdown of immunity and vaccination failures are the consequences. Common mycotoxins associated with mycotoxicoses in poultry include aflatoxins, fumonisins, zearalenone, ochratoxins, and trichothecenes such as deoxynivalenol and T-2 toxins. Oral ulcers and crusts occurring on the palate or tip of the tongue and esophagus can occur with exposure to mycotoxins, including aflatoxin. On necropsy, liver enlargement, gizzard ulcerations, proventriculitis, and enteritis can be observed. Avoid using mouldy ingredients; use toxin binders like zeolites, aluminium silicate or charcoal in the feed can help in controlling of mycotoxin.

Coccidiosis:

Nine species of Eimeria have been described that infect Gallus gallus var. domesticus at various locations along the intestinal tract: E. acervulina, E. brunetti, E. hagani, E. maxima, E. mitis, E. mivati, E. necatrix, E. praecox, and E. tenella. Clinical signs are decreased feed, water consumption, decreased growth rate with high percentage of visibly sickbirds, weight loss, severe bloody diarrhoea and decreased egg production.

Post mortem finding:

1. Accumulation of blood in the caeca.
2. Gross lesions of E. tenella with frank haemorrhaging into caecal pouches in a broiler chicken.
3. Small white spots, usually intermingled with rounded, bright or dull-red spots of various sizes, can be seen on the serosal surface.
4. This appearance is sometimes described as “salt and pepper.”
5. The white spots are diagnostic for E necatrix if clumps of large schizonts can be demonstrated microscopically.