Infectious Coryza in Poultry: Causes, Symptoms & Remedies

Infectious Coryza

Infectious Coryza is a highly contagious upper respiratory infection that primarily affects laying chickens. It is characterized by rapid spread and debilitating symptoms such as foul odor, swelling of infra-orbital sinuses, and facial edema.

Overview

Infectious Coryza, also known as roup or contagious catarrh, is primarily caused by a bacterium called Hemophilus gallinarum. However, secondary infections often prolong the disease. While the mortality rate is usually below 20%, the disease has significant economic implications due to reduced egg production.

Symptoms of Infectious Coryza

The signs of Infectious Coryza include nasal discharge, facial swelling, excessive tearing, loss of appetite, and diarrhea.

Cause of the Disease

The disease is caused by the bacterium Haemophilus paragallinarum.

Transmission of the Disease

Infectious Coryza spreads rapidly through direct bird-to-bird contact, oculo-nasal secretions, aerosol cough droplets, and contaminated feed and drinking water.

Clinical Signs of the Disease

Older birds are more severely affected by the disease. The major clinical signs include low egg production, decreased feed consumption, nasal and ocular discharge, facial and eyelid edema, and swollen wattles.

Postmortem Lesions

Postmortem examination reveals infraorbital sinuses filled with cheesy exudates, swollen or adhered eyelids due to exudates, and facial edema or swelling.

Diagnosis of Infectious Coryza

Diagnosis is confirmed through the observation of gross lesions and bacterial culture of exudates or swabs.

Prevention and Treatment

Effective control measures include maintaining good sanitation and management practices and implementing an all-in and all-out program to break the transmission cycle and eradicate the bacteria. Vaccination with inactivated vaccines at 20 weeks of age is recommended.

It is crucial to eliminate contact between susceptible and infected birds. Antibiotics such as sulfur drugs, tetracycline, and erythromycin can be used, as recommended by a veterinarian.

Note: Infectious Coryza is more likely to affect overcrowded farms with poor ventilation, dampness, unsanitary conditions, parasitic infestations, and insufficient feed supply. Therefore, addressing these predisposing factors is essential to prevent the disease.

Additionally, it's important to note that both Infectious Coryza and the respiratory form of fowl cholera can be easily eradicated on a poultry farm by rearing young birds on clean grounds away from older flocks. Although birds that recover from these diseases may not show any signs, they can become carriers. Administering vitamins and minerals can aid in speeding up the recovery process.

Chronic Respiratory Disease of Chickens (Infectious Sinusitis of Turkeys)

Chronic respiratory disease is a common condition affecting chickens, turkeys, and other fowl. It is caused by an organism called Mycoplasma gallisepticum and is characterized by symptoms such as nasal exudates, coughing, and debilitation. This disease has been a significant problem in the poultry industry for over 60 years.

Although the mortality rate is not very high, infected birds are more susceptible to other infections. The disease can be spread through direct contact with the hands, feet, and clothing of attendants and visitors.

Predisposing Factors for Chronic Respiratory Disease

Several factors can contribute to the development of chronic respiratory disease:

1. Poor ventilation
2. Inadequate water supply
3. Changes in weather conditions
4. Increased levels of ammonia and dust in the housing environment
5. Drafts, openings, and cracks near the floor of the coop, facilitate the spread and severity of the disease
6. Other forms of stress

Cause of the Disease

Chronic respiratory disease is caused by the bacterium Mycoplasma gallisepticum.

Transmission of the Disease

The disease can be transmitted vertically through eggs and horizontally from bird to bird via infected aerosols. It is often complicated by infections such as E. coli, Newcastle disease, and infectious bronchitis. While Mycoplasma gallisepticum alone causes mild infection, other factors, such as stress, bird movement, debeaking, and other operations, can exacerbate the disease.

It's important to note that Mycoplasma gallisepticum can also be present in the upper respiratory tracts of clinically healthy birds.

Clinical Signs

In adult laying hens, signs of the disease are rare, but they may experience low egg production, particularly at the beginning of the season. Other signs include low feed consumption and increased medication costs.

In broiler chickens, symptoms include coughing, sneezing, ocular nasal discharge, poor feed conversion, and stunted growth.

In turkeys, swelling of one or both infraorbital sinuses and nasal exudates on the wings are common signs.

General Signs of Chronic Respiratory Disease

Some general signs of chronic respiratory disease include sneezing, respiratory rales, swollen sinuses, foamy exudates in the eyes, sticky and serous exudates from the nostrils, and stunted and weakened birds.

Gross Lesions (Postmortem)

Postmortem examination of affected birds may reveal pericarditis, perihepatitis, and air sacculitis. In turkeys, swollen sinuses filled with fluid can be observed.

Diagnosis

Diagnosis of chronic respiratory disease is based on clinical signs, postmortem findings, serological tests, and isolation and identification of the causative organism.

Treatment

Treatment of chronic respiratory disease is challenging as it usually does not eliminate the infection and does not prevent egg transmission. However, antibiotics such as oxytetracycline and tylosin may be used to manage the symptoms and control secondary bacterial infections.

Prevention

Preventive measures play a crucial role in controlling chronic respiratory disease. Vaccination of chickens is recommended to reduce the incidence and severity of the disease. It is also advisable to purchase chicks and poults from Mycoplasma-certified-free breeder flocks.

Yolk Sac Infection (Omphalitis or Naval Infection)

Yolk sac infection is a significant cause of mortality in baby chicks during the first 3-4 days after hatching. It occurs due to bacterial infections aggravated by poor hygiene in breeding farms and inadequate management practices at the hatchery.

The primary microorganisms responsible for yolk sac infection are Staphylococci, E. coli, and Pseudomonas.

Causes of Yolk Sac Infection

Yolk sac infection occurs due to the following factors:

1. Shell contamination on the farm leads to the penetration of bacteria through the shell pores into the yolk.
2. Inadequate control of humidity levels in the hatchery.
3. Incomplete withdrawal of the yolk into the abdominal cavity. Remnants of the yolk stalk or other tissues protruding from the navel become infected, although they are usually culled at the hatchery.

Clinical Signs of Yolk Sac Infection

The first indication of yolk sac infection is an increase in the number of dead chicks in the boxes from the farm or hatchery. Infected chicks often have a wet appearance with a foul odor. Yolk and fluid may be seen oozing from the navels, and the down of affected chicks is discolored and matted.

Enlarged yolk sacs cause abdominal distention, which may rupture during the examination. The skin around the navel is congested and inflamed, and unhealed navels may protrude if humidity levels were high during hatching. Increased mortality rates are observed in the first two weeks after hatching.

Diagnosis

Diagnosis of yolk sac infection involves a bacterial examination of the yolk from individual chicks, which reveals profuse growth of bacteria, with two or more types predominating. Examination of fresh carcasses can also aid in diagnosis.

Control of Yolk Sac Infection

Treating the entire batch is generally ineffective, but supportive measures can aid in recovery, including providing additional heat and vitamin supplements in drinking water. Antibiotics may be recommended based on the specific bacteria identified during diagnosis.

Conclusion

Infectious Coryza, Chronic Respiratory Disease, and Yolk Sac Infection are significant health concerns in poultry farming. Understanding their causes, clinical signs, and preventive measures is crucial for effective disease management and maintaining a healthy flock. Regular veterinary consultation and adherence to good hygiene practices are essential in preventing and controlling these diseases.