Chicken-origin Riemerella anatipestifer disease is a bacterial disease caused by chicken-origin Riemerella anatipestifer. When this pathogen infects ducks, the disease is also known as duck infectious serositis, new duck disease, duck septicemia, duck infectious disease syndrome, and duck Pasteurella disease, among other names. To date, 25 serotypes of Riemerella anatipestifer have been reported. This is a highly prevalent infectious disease that can spread among waterfowl such as ducks and geese, as well as chickens and wild birds. Recently, chicken-origin Riemerella anatipestifer disease has appeared in areas with dense white-feathered broiler production, such as Shandong and Liaoning. It presents with paralysis and signs of three inflammations, accompanied by increased mortality, causing significant losses to many white-feathered broiler farming enterprises.
 
　　Age at infection
 
　　The disease can occur within the first seven days, presenting pathological changes involving three inflammations. The first outbreak point is after the first immunization. If, after the first immunization, only respiratory symptoms worsen and no obvious anatomical changes are seen, then, if respiratory disease is not handled properly, around 15 days of age becomes the second outbreak point. As long as the flock’s condition has not clearly improved through husbandry management and medication intervention before 20 days of age, any age after 20 days may become the third outbreak point. This may be related to the level of husbandry management and whether the medication regimen is appropriate, resulting in differences in disease severity and age of onset (outbreaks are mostly mixed infections rather than outbreaks caused by Riemerella anatipestifer alone).
 
　　Mixed infection
 
　　1, among bacterial diseases, coinfection with E. coli is the most common, at nearly 100%. This is because E. coli is detected in every single case in which Riemerella anatipestifer is detected in chickens and ducks.　
 
　　2, on the viral side: the coinfection rate is highest with variant-strain infectious bursal disease (80%), followed by infectious bronchitis, H9, and chicken infectious anemia; Newcastle disease has a relatively lower coinfection rate.
 
　　Clinical Symptoms
 
　　1, initially, respiratory problems are the main issue, primarily presenting as coughing, with a wet cough and mild rattling. Treatment is not very effective, and the condition does not improve despite prolonged treatment.
 
　　2, head swelling may occur, but it is much less likely than with influenza　

　　3, pronounced lethargy, weight loss, dry claws, closed eyes, a tucked-in neck, ruffled feathers, paralysis, and lying prone without moving.
　　
　　4, mortality in most chicken flocks continues for a long time, sometimes until they are ready for market, and the response to medication is unsatisfactory. An unusual pattern also occurs in which a large flock appears to be doing well, yet daily mortality and culling remain high.　

　　5, swelling of the hock joints, with contents ranging from purulent to caseous material.
 
　　Necropsy findings
 
　　1, mainly characterized by pericarditis, airsacculitis, peritonitis, and perihepatitis. Pericarditis and peritonitis are the most severe and occur earliest.

　　2, another feature is the condition of the exudate: it may be yellow fibrin or slightly gelatinous (more evident around the liver). The time it takes for infectious ascites to develop is significantly shorter, and the probability is greatly increased. One point should be emphasized here: these pathological changes are not caused solely by chicken-origin Riemerella anatipestifer; other bacteria and viruses are also involved.

　　3, in white-feather broiler flocks, necropsy may reveal incomplete oviduct degeneration caused by pathogen infection, with caseous material obstructing the oviduct. However, this occurs at a relatively low rate.

　　Formulation and use
 
　　The prescription is formulated by combining florfenicol, micronomicin, doxycycline hydrochloride, colistin sulfate, mequindox, anti-inflammatory and antipyretic drugs, diuretic and detoxifying drugs, liver- and kidney-protective agents, and broad-spectrum potentiators. This formulation is highly effective against the chicken-origin Riemerella anatipestifer that causes this disease. For use, dissolve the above drugs separately, then add them together with oral glucose to the flock's drinking water for centralized administration. A course of four to five consecutive days is sufficient.