Chicken infectious rhinitis is an acute upper respiratory infectious disease caused by Haemophilus parahaemolyticus, with a fast transmission rate. Its characteristics include nasal and sinusitis, facial swelling, sneezing, runny nose, conjunctivitis, tearing, etc. It mostly occurs in broiler chickens and laying hens. Once the disease is transmitted, it will cause serious economic losses to the breeding farm.

1. Case Introduction

  & nbsp; In September 2023, there will be 26000 Wenchang chicken on hand in a farm in Kaiping, Jiangmen. The chickens will be 87 days old. Due to the rain, after the chickens are drenched in the playground, the feed intake will decline on the third day. More than 20 puffy faced chickens will be found sneezing, accompanied by runny nose. On the the fourth day, puffy faced chickens will continue to increase, most of them are unilateral swelling, and there are not many dead chickens, 4-6 chickens a day. The preliminary diagnosis is that the chicken flock is infected with infectious rhinitis. In order to further confirm the diagnosis, diseased materials are collected and sent to the laboratory for testing.

Laboratory test results:

The laboratory test result is rhinitis, which is consistent with the preliminary diagnosis. Take compound sulfamethoxazole soluble powder and feed continuously for 5 days, while drinking water with calcium carbapenem for 2 days. The swollen faced chickens did not increase, and their feed intake returned to normal and was well controlled.

The eyelids of the sick chicken swell, forming scabs around the nostrils.

2. Diagnosis of chicken infectious rhinitis

2.1 Based on epidemiological diagnosis

Infectious rhinitis can occur in all age groups of chickens, but older chickens are more likely to be infected. Chickens over 3 months old are most likely to be infected, with a incidence rate of more than 60%, a mortality rate of about 5-20%, and a drop of more than 10% in egg production rate of laying hens. The incubation period of chicken infectious rhinitis is relatively short: 1-3 days. From the perspective of clinical epidemiology, chickens have low resistance and are prone to infection, including poor environment and unscientific feeding methods, which can cause infectious rhinitis. From the perspective of high incidence seasons, autumn and winter are the high incidence periods.

2.2 Diagnosis based on clinical symptoms

  The symptoms of chicken infectious rhinitis are quite obvious and can be diagnosed based on the clinical symptoms of infectious rhinitis. Infectious rhinitis usually lurks for 1-3 days. If not treated in a timely manner, infectious rhinitis can quickly spread in the chicken flock, and after 3-4 days, the entire flock will be infected. During the feeding process, when chickens experience fever, decreased feed intake, and accompanied by runny nose, which first flows out serous nasal fluid and then becomes mucous or thick, and sick chickens frequently shake their heads, sneeze, and swell their faces, they may be infected with infectious rhinitis.

2.3 Diagnosis based on pathological changes

  From the perspective of pathological changes, infectious rhinitis can also be diagnosed. The pathological changes mainly involve acute inflammation of the nasal cavity and mucosa of chickens, with obvious symptoms of nasal mucosal bleeding, swelling, excessive mucus, and clots, resulting in the appearance of many cheesy necrotic substances. In addition, cystitis is also one of the manifestations of its lesions. When conjunctivitis occurs, the conjunctiva becomes congested and swollen, and in severe cases, it can cause blindness, deformation, bleeding, atrophy of egg follicles in laying hens, and sometimes accompanied by yolk peritonitis, which are prominent manifestations of the disease.

2.4 Laboratory Diagnosis

At present, PCR diagnosis is commonly used in laboratories. PCR methods are simple, fast, specific, and highly sensitive, and can be used for rapid diagnosis of infectious rhinitis.

2.5 Differential diagnosis

Infectious rhinitis: Most of the face shows unilateral swelling, without turning purple, with a rapid onset and fast spread. Food intake decreases, eyes close as if sleeping, and there is a reluctance to walk. The quality of eggshells does not change much, the mortality rate is low, and sulfonamide drugs are effective in treatment.

Chronic respiratory disease: Respiratory symptoms persist for a long time, and chickens with swollen faces spread slowly in the flock. There is little change in mental and feeding habits, and the disease course is long, prone to recurrence. Inflammation of the infraorbital sinus forms hard nodules, and antibiotic treatment is effective.

3. Prevention and control measures for chicken infectious rhinitis

3.1 Take preventive measures

  & nbsp;  Develop good biosafety measures, adopt a full in and full out feeding mode, prohibit the mixing of chickens of different ages, and strictly prohibit the purchase of seedlings and other poultry products from epidemic areas. Reasonable feeding density, good ventilation in the chicken coop, and appropriate supplementation of vitamin A rich feed in the feed& nbsp;

3.2 Actively getting vaccinated for prevention

  & nbsp; & nbsp; Immunization is an effective measure to control infectious rhinitis in chickens. Currently, mineral oil inactivated vaccines are commonly used, but there are also aluminum gel inactivated vaccines. According to the current epidemiological situation in China, the main outbreaks are Group A and Group C, with relatively less isolation of Group B. It is recommended to choose trivalent (A group+B group+C group) or bivalent (A group+C group) inactivated vaccines for immunization of chickens 2-3 weeks before the susceptible age. It is recommended to have two immunizations before the start of the breeding season, one of which should be scheduled one month before the start of the season, and then strengthen the immunization every six months thereafter.

3.3 Strengthen environmental disinfection work

Chicken infectious rhinitis requires strengthened environmental disinfection to reduce the load of Haemophilus parahaemolyticus in the chicken coop environment and lower the incidence of rhinitis. The chicken coop is the main place for chicken growth. Only by improving and enhancing the environment of the coop and regularly disinfecting it can a good environment be provided for chicken growth, ensuring that chickens grow in a clean environment. Before disinfecting the chicken coop, it is necessary to choose disinfectants reasonably. Commonly used disinfectants include iodine preparations and quaternary ammonium salts. These disinfectants not only achieve good disinfection effects, but also do not have side effects on the chickens, ensuring their healthy growth.

3.4 Drug prevention and treatment

  & nbsp; Streptomycin and sulfonamide drugs are the preferred drugs for treating this disease. Streptomycin is administered in injection form, with 80000 to 100000 units per kilogram of body weight. Sulfonamide drugs are mainly used in the form of mixed feeding or mixed drinking. Sulfamethoxazine, which has relatively low toxicity, can be used in combination with synergists in a ratio of 5:1. This combination can improve the efficacy, and NaHCO3 (baking soda) can be added appropriately to feed or drinking water.

4. Conclusion

The occurrence of chicken infectious rhinitis is closely related to the environment and feeding management of the breeding farm, and once it occurs, it will have adverse effects on the chicken population. The disease should be diagnosed in combination with epidemiology, clinical symptoms, pathological changes, laboratory diagnosis, etc., and the disease should be prevented and controlled by strengthening daily management, strengthening environmental disinfection, regular vaccination, using high-quality feed and other measures, so as to effectively reduce the incidence rate and mortality of infectious rhinitis in chickens.