Differential diagnosis and Prevention of Newcastle Disease and Avian Influenza in chickens

Newcastle disease and avian influenza are highly contagious diseases caused by viruses, which can occur all the year round and occur frequently in winter and spring. In the industrial production, both diseases occur frequently, and the losses caused by them are very serious. The majority of farmers attach great importance to this and strengthen their various prevention and control efforts, but the difference between the two diseases is not very clear. In this paper, the pathogens, clinical symptoms and pathological changes of Newcastle disease and avian influenza are compared as follows.

Pathogen

A distinction should be made between chicken plague and bird flu.

Chicken Newcastle disease:

It is caused by paramyxovirus family mumps virus, which can infect chickens of all ages, especially chicks. Clinically, most of them are mixed or atypical.

Chicken avian influenza:

It is caused by Asian influenza A virus of Orthomyxoviridae. It has the characteristics of rapid epidemic and long duration. It has certain mutual sensitivity to birds, among which chickens, ducks, geese and other birds are the most susceptible.

Clinical symptoms

Chicken Newcastle disease: typical Newcastle disease is the most acute and acute. At the beginning of the disease, it shows elevated body temperature, depressed spirit, loss of appetite, purple crown and beard, and a large amount of mucus at the end of the beak from time to time. A large amount of sour and foul-smelling gray-white mucus can be released from the sour sour sac when inverted, dyspnea can produce cackling or wet snoring, diarrhea, green, yellowish-green, yellowish-white fine stool. Subacute and chronic mainly show neurological symptoms, such as wing paralysis, claudication, neck twisting, dyskinesia and so on. Atypical Newcastle disease mostly occurs in vaccinated chickens, which is characterized by mild respiratory symptoms, decreased egg laying rate, discoloration of eggshell, mild abnormal eggs, high morbidity, low mortality and diarrhea.

Chicken avian influenza: highly pathogenic avian influenza can see elevated body temperature, dyspnea, lethargy, loss of appetite, purple-black crown and meat beard, thickening and hardening, necrotic nodules, swollen head, tears, diarrhea and yellowish-green loose stool above. Purple or dark red bleeding spots can be seen on the hairless legs and foot scales, the laying rate of adult laying hens has dropped greatly, and most chickens die of paralysis and exhaustion. Low pathogenic avian influenza is mainly characterized by dyspnea, decreased laying rate and other mild changes.

Pathological changes

Chicken Newcastle disease:

There are bleeding spots between glandular gastric mucosa, nipple and nipple, atypical faint bleeding, mucus turbidity; intestinal congestion, bleeding, especially in the ascending segment of duodenum, anterior and posterior yolk stalk, and ileocecal end. There are round or jujube-shaped necrotic ulcer foci on the small intestinal mucosa; congestion and bleeding are found in the rectum and cloacal cavity, showing spots or brushes, and cecal tonsils are red and swollen and ulcerated.

Chicken avian influenza:

The margin of pancreas is congested, bleeding, with grayish-white or yellowish-white necrotic foci; digestive tract lesions are similar to Newcastle disease, but the difference is adenogastric nipple swelling, suppurative bleeding, duodenum, cecal tonsil without ulcer; adult laying hens can see white or yolk purulent exudates or bean curd-like cheese-like substances in the fallopian tubes and yolk exudates in the abdominal cavity.

The pathological changes of other tissues and organs have no obvious significance in clinical diagnosis and differential diagnosis of Newcastle disease and avian influenza.

Prevention and cure measures

1. Put an end to pathogens invading chicken flocks, cut off all possible ways of transmission, strengthen feeding management and daily hygiene work, and strictly implement the disinfection system.

2. Reasonably formulate scientific immunization procedures, do a good job of vaccine vaccination, and regularly do a good job of antibody detection, in order to strengthen immunity from time to time. Newcastle disease vaccine and avian influenza vaccine should be used reasonably, and attenuated vaccine and virulent vaccine should be used in coordination to enhance the antibody level of the body and improve immunity.

3. As soon as a suspicious epidemic disease is found, it is necessary to diagnose and deal with sick and dead chickens in time. Emergency prevention should be taken against threatened chickens and active treatment should be given to sick chickens to prevent the spread of the epidemic and secondary infection.

4. Highly pathogenic avian influenza shall be dealt with in strict accordance with the relevant national regulations on disease prevention, and mild avian influenza and Newcastle disease can be treated in the following ways:

Vaccination:

Newcastle disease: if the whole population casualty rate is less than 10%, the whole population can be immunized with attenuated vaccines such as IV line and clone-30 according to 5-7 times of emergency drinking water, or 2 times of line I can be urgently vaccinated, otherwise death can be controlled with drugs first.

Mild avian influenza: emergency immunization of uninfected chickens in the surrounding area with H9 and H5 avian influenza vaccines.