Regulating the chicken coop environment during autumn and winter seasons
 & nbsp;   Avian infectious rhinitis is an acute upper respiratory tract disease caused by Haemophilus parahaemophilus. It is widely distributed, with a high incidence rate and a long course of disease. It can occur all year round, but it often occurs in autumn, winter and early spring. Cold and humid climate, excessive chicken population density, and poor ventilation can all promote the onset of this disease.

Disease characteristics

Transmission route and source of infection: The disease is mainly transmitted through the respiratory and digestive excreta of infected chickens. Sick chickens (especially chronic disease chickens) and latent carrier chickens are the main sources of infection. The pathogens they excrete are spread through air, dust, drinking water, feed, and other sources. Drinking water contaminated with pathogenic bacteria is often the main cause of the disease in newly infected chickens.

Although the occurrence of this disease does not have obvious seasonality, it is more common from October to May of the following year, especially from December to February of the following year, which is the high incidence period of this disease. This may be due to the fact that cold weather is conducive to the in vitro survival of the pathogen. Due to the cold season, farmers generally pay attention to insulation and do not pay enough attention to ventilation, resulting in air pollution in the house.

Clinical symptoms and pathological changes

In the early stages of the disease, the feed intake of the chicken flock decreases, and some chickens may experience tearing, accumulation of tear bubbles in the eye sockets, sneezing, nasal twitching, and thin mucus flow from the nostrils. As the disease progresses, one or both sides of the sinus become swollen, eyelids become swollen, and thick secretions flow from the nostrils. After drying, they form yellow pus crusts, have an unpleasant odor, and have difficulty breathing. In the later stage, diarrhea occurs, yellow green loose feces are pulled, and the egg production rate decreases by about 20%.

Laboratory diagnosis

Smear microscopy was used to collect secretions from diseased chicken eyes, nasal cavities, and infraorbital sinuses. After staining the smear, microscopic examination revealed the presence of Gram negative rods, which were polymorphic and occasionally filamentous, with capsules surrounding the bacterial cells.

Bacterial isolation and cultivation were performed by sterile operation to collect nasal and infraorbital sinus secretions from diseased chickens, which were directly streaked and inoculated onto chocolate agar agar plates. After 48 hours of cultivation in a 37 ℃, 10% CO2 environment, smooth, raised, light gray, semi transparent colonies with a diameter of 0.5 mm to 1.0 mm were formed. Some colonies were surrounded by rainbows, and individual colonies were selected for smear microscopy. The bacteria were still Gram negative, polymorphic, and some were filamentous.

Treatment measures

medication:

(1) Generally, sulfonamide drugs are the primary treatment for this disease (such as sulfamethoxazole, sulfamethoxazole, sulfamethoxazole, etc.), with the initial dosage doubled. For example, Sufukang (compound sulfamethoxazole suspension): Mix 300g of water per bottle, maintain at 500g of water per bottle, and use continuously for 4 days. After a 3-day interval, use Sufukang again for 3 consecutive days.

(2) Severely ill chickens: Inject streptomycin intramuscularly at a dose of 20mg/kg/w twice a day for 3 consecutive days.

Vaccine immunization: A-C bivalent oil emulsion inactivated vaccine, administered once intramuscularly between 25 and 50 days of age.

Strengthen feeding management, reduce feeding density, improve ventilation conditions in the chicken coop, carry out disinfection work, regularly disinfect the inside and outside of the coop, reduce the spread of bacteria, and provide sufficient nutrients to the chicken flock. ShandongChicken raising equipmentManufacturer  Shandong Duck Farming Equipment Manufacturer; Shandong Egg Box Manufacturer; Chicken coop heater manufacturer