aviculture au maroc

 

study of poultry projects

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Colibacillosis

 

 

 

Introduction

 

Coli-septicaemia is the commonest infectious disease of farmed poultry. It is most commonly seen following upper respiratory disease (such as Infectious Bronchitis) or Mycoplasmosis. It is frequently associated with immunosuppressive diseases such as Infectious Bursal Disease Virus (Gumboro Disease) in chickens or Haemorrhagic Enteritis in turkeys, or in young birds that are immunologically immature. It is caused by the bacterium Escherichia coli and is seen worldwide in chickens, turkeys, etc.

Morbidity varies, mortality is 5-20%. The infectious agent is moderately resistant in the environment, but is susceptible to disinfectants and to temperatures of 80°C.

Infection is by the oral or inhalation routes, and via shell membranes/yolk/navel, water, fomites, with an incubation period of 3-5 days.

Poor navel healing, mucosal damage due to viral infections and immunosuppression are predisposing factors.

 

Signs

 

- Respiratory signs, coughing, sneezing.

- Snick.

- Dejection.

- Reduced appetite.

- Poor growth.

- Omphalitis.

 

Post-mortem lesions

 

-Omphalitis and yolk sac infection:

 

There is variable mortality. The navel is edematous and inflamed, with scabs. The yolk sac is poorly absorbed, with an opacified and congested wall, a greenish to yellowish content. Aerosacculitis and pericarditis

 

colibacilose

 

.Cellulite:

 

Edema and subcutaneous caseous exudate are observed in the ventral abdominal region and especially under the thighs. The bird shows no clinical signs, but its carcass is seized at the slaughterhouse, which can cause major economic losses.

 

colibacilose

 

Swollen head:


It is a form of cellulite located at the level of the head, which begins in the periorbital region.

 

colibacilose

 

 

Genital forms:

Salpingitis and ovaritis: A caseous, sometimes lamellar exudate is observed in the oviduct, often associated with intra-abdominal egg-laying

 

colibacilose

 

Enteritis:

 

The intestines, especially the caeca, are pale and dilated by a liquid content.

 

colibacilose

 

Respiratory forms:

The birds are indolent and anorexic. They have non-specific respiratory symptoms: rales, coughing, sneezing, throwing, sinusitis.

At the lesional level, there are lesions of inflammation of the visceral serosa: pericarditis, perihepatitis, aerosacculitis, more or less exudative.

 

colibacilose

 

 

Acute systemic form or colisepticemia


There is variable (sudden) morbidity and mortality. The lesions are non-exuding. The liver is enlarged, with some areas of degeneration. The spleen is enlarged with points of necrosis. There are multiple inflammatory lesions: pericarditis, perihepatitis, aerosacculitis, pneumonia, yolk sac infection, arthritis, osteomyelitis, tenosynovitis, etc.

 

 

colibacilose

 

Diagnosis

 

Isolation, sero-typing, pathology. Aerobic culture yields colonies of 2-5mm on both blood and McConkey agar after 18 hours - most strains are rapidly lactose-fermenting producing brick-red colonies on McConkey agar.

Differentiate from acute and chronic infections with Salmonella spp, other enterobacteria such as Proteus, as well as PseudomonasStaphylococcus spp. etc.

 

Treatment

 

Amoxycillin, tetracyclines, neomycin (intestinal activity only), gentamycin or ceftiofur (where hatchery borne), potentiated sulphonamide, flouroquinolones.

 

Prevention

 

Good hygiene in handling of hatching eggs, hatchery hygiene, good sanitation of house, feed and water. Well-nourished embryo and optimal incubation to maximise day-old viability.

Control of predisposing factors and infections (usually by vaccination). Immunity is not well documented though both autogenous and commercial vaccines have been used.