(intestinal serosa, mucosal congestion, hemorrhage, swelling, etc.)
1 pathogen analysis
Escherichia coli, Gram staining is negative, the bacteria are large, long rod-shaped, there are a variety of serotypes, the most common is 02: K, 078: K8. , 01: K, three serotypes. The bacteria are susceptible to drug resistance.
2 routes of transmission
All ages can be infected, with the pigeons and children being more serious and causing a large number of deaths. Old birds are mostly sporadic and sporadic. The infection route is more common in the respiratory tract, followed by the digestive tract, and can also infect the offspring through the egg delivery route. The disease has no obvious seasonality, and there is a little more onset in the late winter and early spring. Poor feed management, poor sanitation, climate catastrophe, nutritional imbalances and other stress factors can induce the disease. In general, pigeons have fewer E. coli pathogens, mostly secondary or concurrent infections. If the pigeon suffers from type I paramyxovirus disease or mycoplasma mycoplasma, the E. coli that causes the pigeon to be infected with the respiratory tract has a higher susceptibility. When the pigeon is attacked by mycotoxins and salmonella, the body defense system is damaged, and the mold can also be damaged. It causes immunosuppression, reduces the body’s ability to resist disease, causes liver and kidney lesions and intestinal mucosal lesions, and makes exogenous E. coli multiply. Endogenous E. coli multiplies and spreads to various tissues and organs of the body through blood. Types of colibacillosis.
3 Clinical Symptoms
The incubation period of this disease ranges from several hours to three days, and often has the following clinical manifestations.
1 Acute sepsis: generally manifested as depression, loss of appetite, desire or abolishment, loose feathers, standing, tears, runny nose, difficulty breathing, yellow or white or yellow-green dilute Finally died and died. The most acute cases suddenly died, and some had neurological symptoms such as looking up and turning heads before dying. When this type occurs, the pigeons usually do not have symptoms together, but they die in succession. They last for a long time and the cumulative mortality rate can reach more than 50%.
2 Granuloma: This is a general condition with no characteristic clinical manifestations.
3 eye types: one after another, mild head swelling, unilateral or bilateral ophthalmia, swollen eyes, closed eyes, tears, crowded or crouched, a few breathing difficulties. The milder symptoms of sputum torticollis, diarrhea, yellowish white or green watery stools; severely blind eyes, no food, no drink, and finally died of death.
4Other types: all caused by local infection of E. coli. Such as peritonitis, generally the yolk yolk peritonitis of the hen is more, E. coli destroys the ovary and causes the yolk to enter the abdominal cavity and causes peritonitis is more common; the umbilical inflammation (mainly the coccidiosis caused by the mixed infection of Escherichia coli and other pathogens) Early in the chick, the umbilical cord breakage is not well healed, causing local redness and inflammation.
4 necropsy lesions
1 acute septic type: see the sac filled with foodstuffs, have a special odor, intestinal congestion, hemorrhage, splenomegaly, dark color, sometimes abdominal cavity Fluid. The characteristic lesions are pericardial, perihepatic and air-bag covered with pale yellow or gray-yellow cellulose secretions. The liver has a firm texture and sometimes has a bronze color change.
2 granuloma type: in the chest and abdominal organs, there are different sizes, similar to the shape of the growth of the organism, and some are diffusely scattered, sometimes densely clustered, gray, red, purple, The black and red are different, and the visible content is cut into cheese-like objects, and each organ has different degrees of inflammation.
3 eye type: the sick pigeon is thin, cut the eye, contains yellow-white bean curd-like mass, the outer layer of the eyeball is covered with a turbid pale white film, and the throat has yellow cheese-like Excretion, intestinal mucosal congestion, hemorrhage, congestion, especially the duodenum is the most serious, liver, spleen slightly swollen, tracheal ring bleeding.
4 Other types: manifested as focal inflammation with suppuration, necrosis, and cheese-like exudation. For example, peritoneal inflammation can be seen in the ascites. The abdominal cavity is covered with pieces of solidified egg yolk, which makes the mesentery and intestinal loop adhere to each other. The follicles in the ovary are congested, hemorrhage, and some atrophy and necrosis.
A preliminary diagnosis can be made according to the incidence, clinical symptoms and pathological changes. The diagnosis must be carried out for the isolation and identification of pathogenic bacteria. Serological identification. Acute septic type causes fibrinous inflammation of multiple organs, and it is a differential diagnosis between pigeon chlamydia and streptococcal disease. The latter is common for subcutaneous, muscle, serosal edema and keel subcutaneous bloody liquid, and pigeon primordial disease is unilateral. Symptoms of ophthalmia; granulomatous E. coli disease should be distinguished from liver cancer induced by chronic aflatoxin poisoning in the initial diagnosis. The latter form a nodular mycelium with visible macroscopic appearance.
6 Control measures
(1) Preventive measures for unaffected pigeon farms
Immunization can be based on the specific situation of the pigeon farm Vaccination of E. coli isolated from multivalent vaccines of Avian Escherichia coli or isolated from diseased pigeons. Considering to reduce the pollution problem in the field, if the vaccine is used, the corresponding blood-type inactivated vaccine vaccine should be selected as much as possible. Usually, the immunization is performed twice every interval for 1~3 weeks, and each intramuscular injection is 0.5 ml. 6 months.
Integrated prevention and control measures
1 Adhering to self-propagation and self-supporting is conducive to the purification of this field (group); all in and out is conducive to thorough disinfection and elimination of possible pathogens; Quarantine to prevent the introduction of infected pigeons (eggs).
2 Collect eggs in time to avoid contamination of the eggs with feces.
Three kinds of eggs, hatchery room (room), incubator, egg storage room and brooding room are all treated with formaldehyde fumigation after one batch, which is not sloppy, which is the key to prevent this disease.
4 Pay attention to the feeding management during brooding, give high-quality full-price nutritious diet, clean drinking water, litter should be disinfected by sun exposure, clean the site, house and surrounding environment, utensils and processing utensils every day. To be disinfected, the whole site should be cleaned and disinfected regularly, and rodent and pest control should be carried out regularly.
5 Control the breeding density of the pigeons to prevent overcrowding. Keep air flowing, fresh, and prevent harmful gases.
6 Proper drug prevention, reduce the occurrence of diseases, and usually conduct drug susceptibility tests on isolated strains to determine the types of preventive drugs, thereby reducing the formation of drug-resistant strains and improving the control effect
(3) Treatment measures for diseased pigeon farms
Isolated disinfection and isolation of sick pigeons, timely isolation treatment or elimination, improvement of feeding management, good environmental hygiene, and strict disinfection of lofts.
There are mainly the following treatments for treatment.
1 norfloxacin or ciprofloxacin hydrochloride, mixed with 0.01%~0.02% for 5~7 days.
2 Gentamicin, drinking water at a concentration of 0.03%~0.04% for 5 days. At the same time, 1% to 2% of garlic is added to the feed for feeding, and the curative effect is better.
3 Enemy net, drinking water at a concentration of 0.01%~0.02%, now available for use, for days.
4 For the amount of chlortetracycline and oxytetracycline, sulfonamides and furazolidone, please refer to “seven pigeons salmonella”. Other drugs may also be used according to the situation: ceftiofur (Sidefu, Suo Xingling, Sucosheng), florfenicol (flufenicol), apramycin (apramycin, Abramycin) , enrofloxacin (ethyl ciprofloxacin, bai disease), danofloxacin mesylate (mononofloxacin), ampicillin (ampicillin, ampicillin), streptomycin, kana Neomycin, neomycin (fremycin, neomycin B), tylosin (tyramycin, tyonol), amikacin (butylamine kanamycin), spectinomycin (spectacular Neomycin, spectinomycin, spectinomycin-lincomycin (licomycin), doxycycline (doxycycline, deoxytetracycline), ofloxacin (fluoxazine), sulfonamide Methoxypyrimidine (anti-inflammatory sulfonate, sulfonamide-5-methoxypyrimidine, SMD), sulfachlorodadine sodium, sarafloxacin, and the like.