Salmonellosis is a dangerous infectious disease that affects animals, birds and people. The main reason provoking its development in domestic chickens is improper care. The disease affects the gastric tract, in advanced stages it is accompanied by arthritis and pneumonia. The article will examine in more detail the disease and methods for its treatment in chickens.

What is this disease

The disease belongs to the polyetiological group. Mostly affects the digestive system, causing concomitant complications in the form of colitis, enteritis.The main danger is that salmonella sticks are able to persist for a long time in the external environment:

• in liquid - 5 months;
• in whole milk - 20 days;
• in kefir - 2 months;
• in cheese - 12 months;
• in eggs - 9 months;
• in frozen meat products - 6 months;
• in the upper layers of the soil - 18 months.

Important! Salting and smoking of meat products obtained from chickens practically have no effect on pathogenic microorganisms.

The causative agent and sources of infection

The causative agents of the disease are a large group of Salmonella rods, including 2200 serotypes. The new classification, compiled in 1987, combines them into one species, including 7 subspecies, which are distinguished by DNA hybridization and biochemical composition. Most of them are equally dangerous for animals, birds and humans.

Salmonella - moving sticks with flagella 2–4 ​​× 5 microns in size. Develop rapidly in a warm, humid environment. Favorable temperature conditions for the development of salmonella - + 6–46 ° C. The main source of infection is food and water.Bacteria are transmitted by contact, so sick animals, birds and humans themselves spread the infection. With the spread of salmonellosis among poultry, the main danger is chickens, not their eggs. At the time of passage through the rectum, feces containing the stick remain on the shell. After 3 days, the bacteria penetrate the shell and begin to actively synthesize their own kind.

Important! The meat of animals and poultry is inseminated by bacteria during life or posthumously with improper slaughter or butchering of the carcass of an animal carrier.

The rapid development of the disease is observed in the warm season. This is due to the emergence of positive conditions for the development of pathogenic microflora.

Pathogenesis

Salmonella bacillus has 3 main antigens:

1. Thermostable.
2. Thermolabile.
3. Capsule.

Some serotypes have a virulent antigen, which is part of thermostable, and mucous. Pathogenesis is due to liposaccharide endotoxin and cholera-like enterotoxin. Once in the body of the bird with food or drink, the stick moves along the digestive tract and stops in the small intestine. Here she begins to multiply actively.In the rectum, it penetrates into macrophages and begins to multiply rapidly in them. Gradually, salmonella overcome the cellular epithelium and penetrate the blood and lymph nodes. In the intestinal mucosa, cell membranes are destroyed with the release of endo- and enterotoxin, which causes visible signs of the disease.

Signs of Salmonella

Several forms of the disease are classified by the intensity of the lesion and the localization of the main colonies of the rods.

According to the intensity of the development of the disease, salmonellosis can be:

1. Fulminant - observed in chickens hatching from infected eggs.
2. Acute - characteristic of chickens at the age of 1-2 weeks.
3. Subacid - affects the grown young, is characterized by erased symptoms.
4. Permanent - is identified in an adult bird, characterized by a complete absence of symptoms.

At the place of localization:

• intestinal. The location of the colonies of Salmonella coli is the rectum, the main symptom is liquid watery stools;
• articular. Liquid appears in the joint bags of the paws, limbs swell, tremors appear, muscles atrophy partially or completely;
• nervous - causes paralysis, may be chronic or subacid in nature.

In young animals, the disease is accompanied by enteritis; in older individuals, acute and subacute forms are observed. According to the serotype of salmonella affecting chickens, the disease can identify itself with typhoid or pullorosis. The first is characteristic of an adult livestock, the second - for young animals. Individuals suffering from typhoid remain the carriers of bacteria for the rest of their lives. Salmonella infects chickens that consume contaminated water and food.After the disease begins to develop, getting into the rectum, like enteritis, or is destroyed by strong immunity. The accumulation of bacteria in the internal organs is manifested by a local skin reaction. There is inflammation, less often necrosis. In young animals, the pathology has its own symptoms that differ from those for adults. Toddlers become lethargic and lose their appetite, which leads to stunted growth. Plumage becomes rare.

Important! The outcome of the disease depends entirely on the immunity of the bird. The highest mortality rate is at 3-4 weeks of infection: 25-30%.

In adults, the main accumulation of bacteria is identified in the liver and reproductive organs. The disease can be asymptomatic. In the acute stage, there is a sharp rejection of food, a decrease in the level of egg production. At the same time, the plumage is disheveled, the scallops fall on their side and acquire a pale pink color. Disorder of the stool is observed, feces come out in liquid form, painted green.

Pathological changes

The preparation of dead chickens shows multiple lesions of internal organs, changes at the cellular level in the joint bags. In mature individuals, deformed regenerated yolk follicles, filled with purulent exudate of a characteristic green color, are identified. Gall bladder is edematous, scarlet mucous.

When identifying an enteritis bacterium, its cavity is filled with bile with mucus and fibrin. Bile is olive green. In the acute and chronic form, damage to the large intestine is observed, deviations in the appendix cells are especially noticeable.The parenchyma is affected in acute course. There are changes in the mucous tissues of the pulmonary system. The cavity is filled with serous fluid, red densified areas on the mucous membranes. The preparation also shows abnormalities in the heart muscle, the myocardium is distended, and the coronary vessels are filled with stagnant blood.

How to treat salmonellosis in chickens

The complexity of the treatment lies in the high ability of the stick to adapt to the action of antibiotics. The best way is to send obviously sick individuals to the face and to process the entire livestock. Recovering individuals who have undergone successful treatment experience growth retardation and productivity indicators are significantly lower.

There is no guarantee that infection will not occur again. There is a danger that an ill bird will remain a carrier of salmonellosis forever, and this will negatively affect the quality of the entire livestock and may cause human infection.

Disinfection

The bird is transferred to a separate room, pre-disinfected. Total cleaning is carried out in the house: all feeders, nests, drinking bowls, bedding, walls and floors are treated with formalin. Processing is carried out three times. Before settling the hens in the house, for 2-3 weeks, the final treatment is carried out with a 3% solution of copper sulfate.

Antibiotics

Treatment with Levomycetin lasts 2–4 weeks. This is a broad-spectrum drug that effectively eliminates gram-positive and gram-negative bacteria. Concentrated in the liver and kidneys. The working dosage for adult hens is 50 mg / kg body weight, for chickens - 30 mg / kg. You can eat meat after 7 days after the termination of the course. Forcedly killed birds are suitable for feeding carnivores and producing fertilizers.

Enrofloxacin-100 belongs to a new generation of antibacterial drugs; it is most effective in the treatment of salmonellosis. The main active ingredient is fluoroquinolone: ​​penetrating into the cells of an animal organism, it inhibits the development of gyrase, an enzyme involved in the synthesis of pathological microorganisms. The drug is not compatible with tetracyclines. The working dosage is 0.025 ml / kg body weight.The use of meat products is allowed from 12-14 days after the end of the course in 5 days. Concomitant medications are prescribed with antibiotics to maintain normal intestinal microflora: for example, Bifidumbacterin. The drug is a combination of antagonist bacteria that eliminate the negative effects of pathogenic microorganisms. The dosage is prescribed by the doctor.

Folk remedies

Folk remedies in the treatment of salmonellosis are used as additional, supportive therapy aimed at restoring affected organs and enriching the body with vitamins. Mostly use herbal decoctions and infusions.

Infusion of chamomile drug positively affects the condition of the liver and gastric tract. 100 g of dry raw material is poured into 1 liter of boiling water, insisted for 1 hour and diluted with water 1: 5. Give instead of regular drinking.Tansy quickly removes toxins from the body, has a mild calming effect on the walls of the stomach. For 1 liter of boiling water, 30-50 g of dry raw materials will be required. After infusion, the broth is diluted with 10 liters of water and given to the chickens after eating.

Danger to humans

Meat and egg products are dangerous for humans. Infected chickens should be immediately sent for slaughter, while corpses must be disposed of. The use of egg products is possible only with careful processing. After collecting the eggs, they must be cleaned of feces using a 3% manganese solution, then used within 2 days. After touching the shell, be sure to wash their hands with soap. It is not allowed to use products in half-baked form. Salmonella coli is especially dangerous for children under 1 year old.

Did you know? The body of an adult is able to withstand the attacks of infection, suppressing their own immunity. But salmonellosis is notable for bypassing the barriers built by intestinal epithelial cells.

Vaccination and general preventive measures

Salmonellosis cannot be cured, therefore, the main measure of protection is prevention, which includes the following items:

1. When updating the livestock, purchased individuals are kept separately prior to vaccination, helminthization and a full examination for the presence of diseases.
2. Effectively feeding chicks from the first days of life of preparations containing probiotics. This allows you to increase immunity and form a stable microflora in the intestine.
3. Once a month, the chicken coop is disinfected.
4. Every 2-3 months they donate blood of birds and their eggs for analysis to the laboratory.
5. Live avirulent vaccine is used on 3-4 days of life of chickens. Revaccination is carried out in adults before collecting eggs for incubation.
6. Chicken coops should be protected from rodents and other animals that can transmit the infection.

Most salmonella serotypes are dangerous for all living organisms: bacteria retain their ability to reproduce over a long period. It is better to destroy sick chickens right away so as not to risk their own health.