Colibacillosis is a widespread bacterial disease in the poultry industry caused by Escherichia coli (E. coli). These bacteria are naturally present in the gastrointestinal tract of birds and are excreted in feces, leading to continuous environmental contamination. Birds are frequently exposed to E. coli through contaminated water, feces, dust, and the surrounding environment. The disease results in significant economic losses due to increased morbidity and mortality, especially around the peak and late lay periods of egg production.

Colibacillosis is a leading cause of mortality in layers and breeders, often causing sudden increases in death rates. Inflammation of the oviduct (salpingitis) caused by E. coli infection reduces egg production and leads to sporadic deaths. In some flocks, colibacillosis may become the primary cause of death before or after peak egg production.

Causes of Infection

Since E. coli is a common intestinal bacterium, it is widespread in fecal matter and litter. Contaminated feed, water, and rodent droppings can also introduce E. coli to a flock. Continuous exposure to this bacterium in the environment makes birds susceptible to infection at any stage of growth or egg production.

Predisposing Factors During Peak Production

Multi-age flock environments

Exposure to endemic mycoplasmas (M. gallisepticum, M. synoviae) or infectious bronchitis virus (IBV)

Poor ventilation, leading to high levels of dust and ammonia

Stress in young birds due to the demands of production

Increased levels of endogenous hormones (particularly estrogen)

Predisposing Factors During Late Lay Period

Vent trauma or partial prolapse

High light intensity

Small-framed birds producing large eggs

Excessive fat pads

Clinical Signs

Symptoms of colibacillosis vary based on whether the infection is localized or systemic. Localized infections are less severe, while systemic infections can be fatal. Affected birds often appear undersized and lethargic, typically found near walls or under feeders. Birds with septicemia may be unresponsive and show signs of dehydration, with green feces containing white-yellow urates.

Postmortem examinations reveal polyserositis, with common findings including pericarditis, perihepatitis, airsacculitis, and peritonitis. In peritonitis cases, caseous exudates resembling coagulated yolk material are found in the body cavity, known as egg yolk peritonitis.

Treatment

Antimicrobial treatment should be based on bacterial susceptibility testing. Consult a poultry veterinarian before initiating treatment to ensure efficacy and to avoid promoting antibiotic resistance.

ENROLEX-20

A broad-spectrum antibiotic combining enrofloxacin and colistin for the treatment of bacterial infections in poultry.

Composition:

Each 1 mL contains:

Enrofloxacin: 200 mg

Colistin sulphate: 1,200,000 IU

Excipients to 1 mL

Description:

This combination of enrofloxacin and colistin provides an additive effect. Enrofloxacin, a fluoroquinolone antibiotic, acts against both Gram-negative and Gram-positive bacteria, as well as mycoplasmas. Colistin, from the polymyxin group, is particularly effective against Gram-negative bacteria like E. coli, Haemophilus, and Salmonella spp.

Indications:

ENROLEX-20 is indicated for the treatment of gastrointestinal, respiratory, and urinary tract infections caused by microorganisms sensitive to enrofloxacin and colistin. These include Campylobacter, E. coli, Haemophilus, Mycoplasma, Pasteurella, and Salmonella spp.

Dosage:

For oral administration:

Poultry: Administer 1 liter per 2000 liters of drinking water for 3–5 days.

Withdrawal Times:

Meat and offal: 9 days.

Maintaining a clean environment, reducing stress, and implementing strong biosecurity measures are key strategies to prevent colibacillosis outbreaks in poultry farms.