What Is Melanosis Coli?

E. coli disease (this disease is a general term for diseases caused by some pathogenic serotype strains of Escherichia coli), is an intestinal infectious disease caused by a certain serotype of pathogenic E. coli and its toxins . It can occur all year round, and rabbits of all ages are susceptible. The main threat is from weaning to 4 months old rabbits.

Colibacillosis

Escherichia coli is a medium-sized bacterium with a size of 1 to 3 um × 0.5 to 0.7 um. It has flagella and no spores, and some strains can form capsules. Gram staining is negative. , The biochemical reaction is lively, easy to proliferate on ordinary culture, and has strong adaptability. This bacterium is sensitive to general disinfectants and easily resistant to antibiotics and sulfa drugs.

Clinical symptoms of colibacillosis

Clinical symptoms and anatomical features The following features are the main features, and yellowish brown watery faeces are discharged. Acute cases usually die within 1 to 2 days, and subacutely die about 1 week. The body temperature is normal or low, the abdomen is swollen, there is a drumming sound when it is knocked, and there is a flowing water sound when it is shaken. The affected rabbit's limbs became cold, bruised, and drooling.

A necropsy showed that the liver was enlarged and brittle; pneumonia was edema with bleeding points; the gastric mucosa was detached and the stomach wall had dark brown ulcers of various sizes; the serosa and mucous membranes of the colon and cecum were congested or bleeding; Plastic capsules. In some cases, there are focal necrotic lesions in the liver and heart.

E.coli disease treatment

Spiramycin, 20 mg per kg body weight, intramuscularly; polymyxin E, 0.5 to 1 mg per kg body weight, intramuscularly; gentamicin, 1 to 1.5 mg per kg body weight, intramuscular Injected 3 times a day (the above three are used alternately or combined for better results); kanamycin sulfate, 5 mg per kilogram of body weight, intramuscularly, 3 times a day; enrofloxacin, 0.25 to 0 per kilogram of body weight .5 ml, intramuscular injection, 2 times a day for 3 to 5 consecutive days. In order to improve the treatment effect, it should be performed at the same time as fluid replacement.

E.coli disease prevention

This disease is directly related to feed and hygiene. The feed should be properly matched to ensure a certain amount of crude fiber, and the energy and protein levels should not be too high; the feed should not be changed suddenly, and it should have an adaptation period of about 7 days; strengthen diet hygiene and environmental hygiene, and eliminate mosquitoes, flies, and rats on the feed and Pollution of drinking water; for weaned rabbits, certain drugs can be added to the feed, such as pentamidine, quinethanol, norfloxacin or chloramphenicol; 0.5 to 1% of microecological preparations are added to the feed, For 5 to 7 days in a row; for rabbit farms where the disease often occurs, inactivated aluminum hydroxide vaccines can be prepared from E. coli isolated from this farm. 20-30 day-old rabbits can be effectively injected with 1 ml each To control the occurrence of the disease.

Major cases of colibacillosis

Chicken colibacillosis is a common disease caused by E. coli. These include Escherichia coli peritonitis, salpingitis, umbilitis, synovitis, balloon inflammation, granulomatosis, ophthalmia and other diseases, which are more harmful to the chicken industry.

Popular characteristics

Chickens of all ages can be infected, but due to the effects of breeding management level, environmental sanitation, control measures, and other secondary diseases, the morbidity and mortality of this disease are quite different.

After intensive chicken breeding has been basically controlled, the E. coli disease has a clear upward trend, and it has become one of the main bacterial diseases that endanger chicken flocks, which should be given sufficient attention.

Escherichia coli is common in natural environment, such as feed, drinking water, chicken body surface, hatchery, incubator and so on. Due to the threat of the whole process of chicken raising.

The disease can occur at the chick stage, rearing stage, and adult laying hens. Chicks have acute sepsis, while turkeys are mainly subacute or chronic. In most cases, the infection is more serious due to various stress factors and other diseases. Adult laying hens often occur during the start-up phase, increasing the rate of death and panning, which affects egg production, and production performance cannot be fully exerted. The occurrence of breeder farms directly affects the hatching rate and hatching rate of breeding eggs, resulting in an increase in dead embryos and hair eggs during hatching, and a low rate of healthy chicks.

The disease can occur all year round, and it occurs frequently in rainy, muggy and humid seasons.

Coliform disease is one of the most common diseases in the production of broilers.

Clinical manifestation

There is no characteristic clinical manifestation of chicken colibacillosis, but it has a lot to do with the age of disease onset, the duration of the disease, the affected tissues and parts, and the presence of secondary or mixed infections.

(1) Newborn chick umbilicalitis, commonly known as "big navel". Most of them are related to E. coli. The sick chick is depressed, eats little or no food, has a large abdomen, redness and edema of the skin around the umbilical foramen. Most of these chicks die or are eliminated within one week.

Another manifestation is diarrhea. In addition to poor spirit and appetite, it can be seen that soil-like feces are introduced, and the sick chicks die within 1-2 days. No significant peak was seen in death.

(2) During the brooding period, which includes E. coli disease of broiler chickens, the primary infection is relatively rare and rare, mostly due to secondary infection and mixed infection. Especially when chicken infectious bursal disease occurs in the chick stage, or chronic respiratory diseases of chickens are caused by improper feeding and management. Sick chickens have decreased appetite, depressed spirits, loose feathers, and thinning. It also has symptoms of other diseases. The incidence of broiler chickens is broadly similar.

(3) The onset of flocks in the egg-laying stage is mostly caused by extensive breeding and management, serious environmental pollution, or occurs in humid and rainy seasons. This situation is usually dominated by the primary infection. In addition, it can be secondary to other diseases such as chicken white pheasant, Newcastle disease, infectious bronchitis, infectious laryngotracheitis, and chronic respiratory diseases. The main performance is that the egg production is not high, the egg production peak does not go up, the egg production peak maintains for a short time, and the death rate of chickens increases. The clinical manifestations of sick chickens are such as atrophy of crests, diarrhea, and decreased appetite.

3. Changes in pathological examination After umbilical inflammation of newborn chicks, edema, subcutaneous blood stasis, bleeding, and edema around the umbilical foramen can be seen. The edema fluid is pale yellow or yellow-red. The umbilical foramen is opened, and the dead and umbilical-killed chickens with neonatal chicks are found to have no yolk absorption or malabsorption. The oocysts are congested, bleeding, and the yolk fluid in the sac is thick or thin, mostly yellow-green. Intestinal catarrhal inflammation. Hepatomegaly, sometimes scattered yellowish necrotic lesions, and slightly thickened liver capsule.

Sick and dead chickens infected with mycoplasma are more likely to have hepatosplenomegaly, thickened liver capsule, yellowish white opacity, and easy to peel off. Some of the fibrous membranes formed on the liver surface occur locally, and the entire liver surface is severely covered by this membrane. The liver is purple-brown after peeling off this membrane; pericarditis, pericardial thickening and opacity, and pericardial accumulation of pale yellow liquid; Airbag inflammation is also a common change. The thickening of the airbag sac walls of the chest and abdomen is gray-yellow, and there are various amounts of cellulosic exudate or cheese-like matter in the sac cavity like egg yolk.

Some dead chickens show salpingitis, hyperemia of the mucous membrane, and unequal amounts of cheese-like matter in the lumen. In severe cases, large masses accumulate in the fallopian tube, the wall of the fallopian tube becomes thin, the mass is yellowish white, and the cuts are round. It is dry. Some soft-shelled eggs were found in the abdominal cavity.

Many adult chickens also have yolk peritonitis, and egg yolk fluid is widely spread on the intestinal surface in the abdominal cavity. In the abdominal cavity of the slow-dead chickens, a large amount of cellulose-like substances stuck to the intestines and mesentery. The peritoneum was inflamed, the peritoneum was inflamed, the peritoneum was rough, and some intestinal adhesions were visible.

E. coli granulomas are rarely seen. Granuloma nodules can be seen in the small intestine, cecum serosa, and mesentery, intestinal adhesions are not easy to separate, and the liver appears as necrotic lesions of different sizes and numbers.

Others such as ophthalmitis, synovitis, and pneumonia can only be seen during the occurrence of this disease.

In short, the diagnosis can be made based on the epidemiological characteristics of the disease and more typical pathological changes.

clinical diagnosis

Laboratory pathogen testing methods are used to exclude other pathogenic infections (viruses, bacteria, mycoplasma, etc.), and they are identified as pathogenic serotypes of E. coli before they can be considered as primary E. coli disease; in other primary diseases When isolated from E. coli, it should be regarded as secondary E. coli disease.

Prevention method

In view of the fact that the occurrence of the disease is related to various external stress factors, the prevention of the disease is firstly to strengthen the management of chicken flocks, gradually improve the ventilation conditions of chicken houses, and seriously implement veterinary health and anti-epidemic measures on chicken farms. Breeder farms should strengthen the management of hygienic disinfection for the collection, storage and entire hatching process. In addition, prevention of common multiple diseases should be done well. All these are of great significance to prevent the occurrence of this disease.

Chickens can be treated with drugs after they become ill. In the course of prevention and treatment of this disease, it was found that E. coli is extremely susceptible to drug resistance, and antibiotics such as penicillin, streptomycin, oxytetracycline, and tetracycline have almost no therapeutic effect. Chloramphenicol, gentamicin, norfloxacin, and neomycin have better therapeutic effects. However, strains that are resistant to these drugs have emerged and are increasing. Therefore, in the prevention and treatment of the disease, a drug sensitivity test should be performed in a place where conditions permit, to select a sensitive drug, or to select a drug that was rarely used in the field for the whole group administration, and a satisfactory result can be obtained. Early administration can control sick chickens infected early and promote recovery. At the same time can prevent the emergence of new cases. The chicken is already ill, and the sick chickens that have caused the above-mentioned various pathological changes in the body have very poor treatment effects.

The disease is common, and chickens of all ages can develop disease. The drug treatment effect gradually decreases and the cost of raising chickens is increased. Dead vaccines for E. coli have been made in China, including chicken E. coli polyvalent aluminum hydroxide vaccines and multivalent oil adjuvant vaccines, which have achieved good control effects through field application. Because there are many serotypes of Escherichia coli, seedling-producing strains should be collected from multiple strains of diseased chickens in the region, or isolated strains produced in the field to make their own seedlings will work well. After vaccination of breeder chickens before the start of production, E.coli disease was significantly reduced throughout the egg production cycle. The fertilization rate, hatching rate, and healthy chick rate of the breeder eggs were increased, which reduced the incidence of the disease at the chick stage.

When the E. coli oil adjuvant vaccine was injected into adult chickens, the chickens had different degrees of injection responses after the injection, which mainly manifested that they were not in good spirits, were prone to lying, and reduced food intake. It usually disappears after 1 to 2 days without any treatment. Therefore, seedling injection should be more appropriate before the start of production. Injecting seedlings after opening often affects egg production.

Prevention guidelines

1. Optimize the environment

(1) Select a site and keep it in isolation. The site should be built on a dry terrain, with sufficient water, good water quality, convenient drainage, and far from residential areas (minimum 500m), especially away from other poultry farms, slaughtering or livestock processing plants. The production area is separated from the production area and the operation and management area, and feed processing, breeding chickens, brooding, rearing chicken farms and hatching rooms are separated (500m apart).

(2) Scientific feeding management: temperature, humidity, density, light, feed and management of poultry houses should be carried out in accordance with regulations.

(3) Improve air purification in poultry houses: Reducing the generation and accumulation of harmful gases such as ammonia in chicken houses is a very important measure that chicken farms must take. The common methods are as follows:

Add complex enzyme preparation to feed: If using complex enzyme containing -glucan, it can be added at 1kg per ton of feed, which can be used for a long time.

Add organic acids in feed: such as fumaric acid, citric acid, lactic acid, acetic acid and propanol.

Use micro-ecological preparations: A: Kesaiyou; B: EM preparations, the domestic trade name is "Yi'an".

drug spray: A, peroxyacetic acid, the conventional method is to use 0.3% peroxyacetic acid. Spray at 30ml / m3, 1-2 times a week, and 1-2 times a day in the affected chicken house. B. Paraformaldehyde: 4.5kg of paraformaldehyde is added to 25m2 litter, which can neutralize with ammonia in the air. The ammonia concentration will soon drop to 5 × 10-6, but it will rise back to 100 × 10-6 after 21 days. , So it should be reused.

Wellcome use: This preparation is an extract from the stem of Yucca plant, the main component is saponin.

Oligosaccharides, also known as oligosaccharides, A, glycoterpenoids, how to use them, laying hens (ducks) 400 × 10-6 (with 25% allicin 50 × 10-6), broilers 400 450 × 10- 6, pig 300 ~ 350 × 10-6 mix. B. Filda 2000, the use of additives 0.1% (shake or drink water), the incidence group (such as MD, ND, IB, IBD, AI), etc. increased by 0.2% to 0.5%, after 3 to 5 days, 0.1% Add to use. C. Suda bacteria toxin clear, usage method : broiler chicken health program, 1 to 10 days of age, 21 to 30 days of age, 31 to 40 days of age, and 41 to 50 days of age to drink 4 to 5 days at each stage Add 1kg of water to drink. Laying hen health program, drinking water every 10d for 4d, the other is the same as above.

Mechanical removal: timely excrement of manure, accumulation of sealed fermentation, timely ventilation and ventilation.

Pay attention to environmental management, greening of feeding grounds, planting grass and trees.

2. Strengthen disinfection

(1) Breeding eggs, the environment inside and outside the hatchery and poultry house should be cleaned and disinfected in accordance with disinfection procedures to reduce breeding eggs, hatching and chick infection with E. coli and its spread.

(2) Prevent water and feed pollution: Pellet feed can be used. Drinking water should be added with acidifiers (boliline) or disinfectants, such as chlorine or iodine-containing disinfectants; nipple drinkers should be used for drinking water. Clean and disinfect.

(3) Rodent and insect repellent.

(4) Disinfection of chickens in poultry houses has the functions of dust reduction, sterilization, temperature reduction and neutralization of harmful gases.

3. Strengthen breeder management

(1) Eliminate and deal with sick chickens in time.

(2) Regular preventive administration and immunity against viral and bacterial diseases.

(3) Sperm collection and insemination are strictly disinfected, and one sterilized vase is used for each chicken.

4.Improve the immunity and disease resistance of birds

(1) Vaccine immunization: Multivalent inactivated adjuvant vaccines can be used at home (or dominant strains). The general immunization program is 7 to 15 days old, 25 to 35 days old, and 120 to 140 days old.

(2) Use of immune booster: The emulsified vitamin ADE is preferred, levamisole 200 × 10-6. Vc (Gaowenxi is microencapsulated Vc) mixed feed or water at 0.2% 0.5%; VA1.6 20,000u / kg feed mixed feed; strengthened Vitawang multi-dimensional at 0.1% drinking water for 3 5d.

Yimiaoling: It can be used for the treatment of bacterial or bacterial virus mixed infection, improve the immune effect of vaccination, fight immunosuppression and synergistic antibiotic treatment. Method of use, prevention: 1: 2000 times, treatment: 1000 times, diluted with water, once a day, drink within 1 hour, and use 3d (prevention) and 5d (treatment) together.

(3) Immunity for other common viral diseases: such as ND, IB, IBD, MD, and AI.

(4) To control bacterial diseases such as mycoplasma and infectious rhinitis, vaccine immunization and drug prevention can be done well.

5. Drug control

Sensitive drugs should be selected for preventive administration 1 to 2 days before the age of onset, or for emergency treatment after onset

[1] Antibiotics

(1) Penicillins

A. Ampicillin (Ampicillin): Take 0.2 g / l of drinking water or take 5-10 mg / kg of orally.

B. Amoxicillin: Drink water at 0.2g / l.

(2) Cephalosporins

Cephalosporins are a class of antibiotics obtained by using cephalosporins derived from cephalosporin culture as raw materials and semi-synthetic modification of their side chains. There are 20 commonly used antibiotics, which differ according to the sequence of their invention and antibacterial properties. Divided into 1 to 4 generations.

The third generation includes cefotaxime sodium (cefotaxime), ceftriaxone sodium (ceftizine), cefoperazone (cefotaxime or Pioneer must), and ceftazidime (ceftazidime, fadaxin) ), Ceftizoxime (cefotaxime), cephalosporin oxime (Shifusu, FK207), cefmenoxime (beceast g), cefmenona, laxefate sodium (oxycarboxam , Latacephalosporin). Pioneer must be 1g / 10l water, drink water, use it for 3 d, the first time is 1g / 7l water. Baxianbao: 0.5g / l of water, used for 3d, the first time is 1g / 7l of water.

(3) Aminoglycosides

Gentamicin: 2 to 40,000 u / l of drinking water.

Kanamycin: 20,000 u / l of drinking water or 1 to 20,000 u / kg intramuscularly, once a day for 3 days.

Neomycin sulfate: 0.05% drinking water or 0.02% mixed feed.

Streptomycin: 30 ~ 120mg / kg drinking water, 13 ~ 55g / ton mixed feed, and use for 3 ~ 5d.

(4) Tetracyclines

Soil mold: 0.1% 0.6% mixed feed or 0.04% drinking water, use for 3 5d.

Doxycycline: 0.05% 0.2% mixed feed for 3 to 5 days.

Tetracycline: 0.03% 0.05% mixed feed, used continuously for 3 5d.

(5) Amido alcohols

Chloramphenicol: Mix feed at 0.1% 0.2%, use it continuously for 3 5d or 40mg / kg muscle.

Methanesulfomycin: mixed feed at 0.01% ~ 0.02%, use for 3 ~ 5d.

(6) Macrocyclic lipids

Erythromycin: 50 100g / ton mixed feed for 3 5d.

Tylosin: 0.2% 0.5% mixed feed for 3 to 5 days.

Tiamulin: 125 250g / ton feed, used for 3 5d.

[2] synthetic antibacterials

(1) Sulfonamides

Sulfadiazine (SD): 0.2% mixed feed, 0.1% to 0.2% drinking water, 3d in a row.

Sulfaquinoxaline (SQ): 0.05% ~ 0.1% mixed feed, 0.025% ~ 0.05% drinking water, use for 2 ~ 3d, stop for 2d, and then use for 3d.

(2) Nitrofurans

Furazolidone: 0.03% ~ 0.04% mixed feed, 0.01% ~ 0.03% drinking water, continuous use for 3 ~ 5d, generally no more than 7d.

(3) Quinolones

Ciprofloxacin, enrofloxacin, lomefloxacin, ofloxacin, etc., the prevention amount is 25 × 10-6, the treatment amount is 50 × 10-6, and 3 to 5 days in a row.

(4) Anti-infective botanicals (Chinese herbal medicine)

Coptis chinensis, Huang Cen, Cork, Qinpi, Shuanghua, Pasqueflower, Big Green Leaf, Banlangen, Andrographis, Garlic, Houttuynia cordata.

Etiology of E. coli

E.coli pathogen

According to the structure of the antigen, E. coli is known to have 170 species of bacterial (O) antigens, nearly 103 surface (K) antigens, and 60 flagella (H) antigens, thus constituting many serotypes. Recently, pili antigens have been used for serological identification. The most common serotypes K88 and K99 were named F4 and F5, respectively. Among the serotypes that cause intestinal diseases in humans and animals, enteropathogenic E.coli (referred to as EPEC), enterotoxigenic E.coli (referred to as ETEC), and enteroinvasive E.coli (referred to as EIEC), etc., most enterotoxins Sexual E. coli carries the F antigen. Of the 170 "0" antigen serotypes, about 1/2 are pathogenic to birds, but the most are the four serotypes O1, O2, O78, and O35. E. coli can break down glucose, maltose, mannitol, xylose, glycerin, rhamnose, sorbitol, and arabinose, producing acid and gas. Most strains can ferment lactose, and some strains ferment sucrose. An indigo matrix is produced. Does not break down dextrin, starch, inositol and urea. No hydrogen sulfide, non-liquefied gelatin, V P test was negative, and MR test was positive.

E.coli disease epidemiology

E. coli is a common bacterium in human and animal intestines, and contains about 106 bacteria in 1 g of feces. The presence of the bacteria in drinking water is considered an indicator of fecal contamination. Poultry E. coli is common in chicken farms, especially poorly ventilated chicken sheds, which are most contaminated in litter, air dust, contaminated appliances and roads, septic farms and hatcheries.

Escherichia coli is excreted with feces, and can contaminate eggshells or invade eggs from infected ovaries, fallopian tubes, etc. During the incubation process, the death of avian embryos or the emergence of shells and the occurrence of bacteria are important ways in the spread of the disease. Carrier-borne birds infect healthy birds horizontally. The digestive tract and respiratory tract are common infection portals. Mating or contaminated vas deferens can also cause infection through the reproductive tract. Rodent feces often contain pathogenic E. coli, which can contaminate feed and water and cause infection.

The disease mainly occurs in intensive poultry farms, and various birds are susceptible to the bacteria regardless of breed sex and age. Especially young birds have the highest incidence, such as dirty, crowded, humid and poorly ventilated environments, over-cooled and over-heated, or climates with large temperature differences, long-term presence of toxic and harmful gases (ammonia or hydrogen sulfide, etc.), improper feeding and management, and malnutrition (especially Vitamin deficiency) and stress caused by pathogenic microorganisms (such as mycoplasma and virus) infection can promote the occurrence of this disease.