ORT in Poultry

INTRODUCTION

ORT (Ornithobacterium rhinotracheale) disease is a respiratory infection caused by a Gram-negative bacterium, severely affecting broilers and layers.

In intensive farming, outbreaks commonly occur under poor ventilation, high stocking density, and the presence of pathogens such as IB (Infectious Bronchitis), Newcastle, or Mycoplasma gallisepticum.

PATHOGENESIS AND RISK FACTORS

After entering through the respiratory tract, ORT bacteria adhere to the mucosa of the trachea and bronchi, causing inflammation and stimulating exudate secretion.

  Main risk factors

• High NH₃ concentration (>20 ppm)
• High stocking density
• Poor ventilation
• Coinfection with virus or Mycoplasma

CLINICAL SYMPTOMS AND LESIONS

Clinical symptoms:

• Dyspnea, neck extension, open-mouth breathing
• Coughing, frequent head shaking
• Cyanotic comb due to hypoxia
• Decreased feed intake, reduced weight gain

Environmental risk factors:

• High NH₃ concentration (>20 ppm)
• High stocking density
• Poor ventilation
• Coinfection with virus

SUMMARY OF KPIs

• Mortality rate: 5–15%
• Increased FCR: +5–10%
• Extended rearing period: +5–7 days
• Economic loss: 20–40 million VND / 10,000 birds

TREATMENT PRINCIPLES AND PROTOCOLS

Florfenicol + Doxycycline + Bromhexine
→ Antibacterial and fibrin-dissolving action, helping clear the airways quickly

DOXY (Doxycycline hyclate)

→ Reference dose: 1g / 25kg body weight / day × 5 days

TYLODOX AP

→ Suitable when ORT is coinfected with CRD (Mycoplasma)

TREATMENT PRINCIPLES

(1) Antibiotics – bacterial control

• Florfenicol
• Doxycycline
• Combined usage to reduce drug resistance

(2) Expectorant – resolving blockage

• Bromhexine
• Reduces the risk of rapid suffocation

PREVENTION AND LONG-TERM CONTROL

• Maintain NH₃ < 20 ppm
• Ensure house ventilation
• Reduce stocking density
• Effectively control IB and Newcastle with vaccines
• Manage dry, clean litter

CONCLUSION

ORT is not just a simple respiratory disease but a complex syndrome involving environment, microbiology, and immunity.

Effective treatment requires combining the right antibiotics with expectorant solutions to simultaneously address both the root cause and mechanical consequences.