Identification and treatment of chickens and chickens pullorosis

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Infectious disease of poultry from the order of chicken pullorosis affects chickens quite often, resulting in the death of young animals.

Pullorosis of chickens and chickens

Inquiry on the nature of pullorosis

The infection, called Poultry Pullorosis, is an intestinal infection that affects the parenchymal organs of chickens. It causes inflammation in the ovaries in adult birds, leading to yolk peritonitis. Other names for an infectious disease include dysentery, bacillary white diarrhea (diarrhea).

A distinctive feature of pullorosis in chickens is its asymptomatic course.

The first cases of massive avian Pullorosis were observed in 1889. Then the English scientists called this disorder salmonellosis of birds... The causative agent of Pullorosis in poultry was identified in 1900. Avian typhus, pullorosis, on European territory would have been recorded in 1913, on Russian poultry farms, intestinal infection appeared in 1924, when chickens and turkey poults with signs of this disease were imported.

As a result of the effect of pullorosis on the body of young animals, the number of deaths among chickens reaches 70%. At the same time, the economic damage from it is also associated with a decrease in the productivity of adult chickens, a decrease in their egg production and hatchability of a new generation due to problematic embryonic development of the fetus. Young chickens and turkey poults with Pullorosis begin to lose weight, which directly affects the breeding characteristics of poultry.

Etiological picture of pullorosis

Pullorosis of birds is caused by a pathogen belonging to the order of Salmonella, which is a motionless gram-negative bacillus that does not form spores or capsules. Microbiology classifies the avian typhus causative agent as aerobic.

For the activity of an infectious bacillus, the most optimal temperature is 38 ° C with an alkaline pH of 7.5.

In the usual nutrient medium, the aerobe develops quite quickly, easily forming round forms of translucent colonies with clear outlines and a slightly protruding wet surface. Pullorosis can multiply in a rough form, then it grows in dry colonies.

The causative agent of typhoid fever of birds is significantly resistant to external factors. Thus, in poultry droppings, pullorosis persists for 100 days, in conditions of stagnant water - up to 200, in the soil layer - up to 400. At the same time, in conditions of bird litter that is not replaced for 10 days, the causative agent of bird pullorosis dies.

Scientists have noticed that aerobic pullorosis that has fallen into a garden culture, while maintaining a temperature of 18-20 ° C in a dried state, can live up to 7 years.

A long period of activity of pullor infection is observed in freezing conditions up to 180-190 days.It is possible to inactivate the pullorosis virus by heating to 60 ° C for at least half an hour. At the boiling point, the aerobe dies after a minute, when an infected chicken egg is boiled - after 7-8 minutes.

Various drugs and solutions can lead to the death of the infection:

• 1% formalin is able to destroy Pullorosis in 5 minutes,
• for inactivation with carbolic acid, a concentration of 5% and half a minute of time is required,
• they will cope with the pullor virus with potassium permanganate, naphthazole, bleach with active chlorine in 15-20 minutes.

Scientists note the sensitivity of pullor bacteria to drugs from a number of antibiotics, however, an addictive infection is observed when treatment is carried out with prolonged use of the same medication.

Epizootology

In addition to poultry (turkeys, turkeys, chickens, chickens, guinea fowls, pheasants and quails from the chicken order), among other animals that are prone to pullorosis, rabbits, ornamental pigs, and mice are hatched. A slight resistance against bird pullorosis has been recorded among waterfowl.

Among broilers, typhus is mainly infected meat poultry... The smallest cases of pullorosis in chickens were noted in those types of poultry that are bred to get eggs.

The main route of transmission of the disease is embryonic, when infection passes through infected eggs to newborn young animals. Such cases are noted up to 50%.

Pullorosis is observed in young animals, depending on the age category:

• 5-7 day old chickens suffer from pullorosis more often, the disease progresses in them for 20 days,
• upon reaching the age of 20 days and further, the number of cases in chickens decreases, turning into subacute forms of the course or chronic development.

The transmission of intestinal infections occurs in different ways:

• the source of transmission of the pathogen are sick young animals and adult chickens carrying the bacteria, which, together with excrement, excrete a large accumulation of the causative agent of pullorosis into the environment.
• the penetration of pullorosis into chicken eggs occurs through the contents of the intestines of diseased individuals through the shell pores,
• the sources of bacteria can be fluff, waste, drinking water, feed, left after an infected brood,
• the disease is carried by urban birds (sparrows, pigeons, jackdaws).

Usually, only 25 to 50% of chickens hatch from chicken eggs infected with pullorosis, the rest die during embryonic development.

Pathogenic and clinical picture of avian typhus

Among the factors that contribute to the appearance and development of pullorosis in chickens and chickens, many are associated with the conditions of keeping poultry and its nutritional quality:

• inadequate diet and non-compliance with the feeding schedule,
• crowded living of birds in the poultry house,
• overheating or hypothermia of individuals.

Pathogenesis of infection

If it enters the bird's body, the pathogen at the site of penetration, for example, of the mucous membranes of the intestine, stomach, pulmonary system, begins to multiply and through the circulatory system begins to spread to all internal organs, leading to pathology of the heart, liver, kidneys, ovaries, spleen.

In the process of reproduction, pullorosis releases toxins into the body, leading to the death of the embryo.

At hatching, most chicks are already carriers of pullorosis, which manifests itself with signs of acute intoxication. In the body of an adult bird, the pathogen heats up in the egg-forming organs and from time to time is excreted along with the egg-laying.

Among the consequences of transferring pullorosis in birds, when proper treatment is provided, is the immunity to secondary infection developed against intestinal infection due to the formation of antibodies in chickens who have undergone pullorosis. This feature formed the basis of breeding work when breeding chicken lines resistant to avian typhus.

Clinical signs

The latent period of bird pullorosis can last from a day to 20. At the same time, there are:

• congenital form, in which already sick chickens hatch from infected eggs,
• postnatal form, when healthy individuals become infected from patients in the process of their joint maintenance.

With a congenital form that develops in 3-5 days, the disease manifests itself in chickens in the form of general weakness and drowsiness. Young animals lose their appetite and refuses to feed, moves with lowered wings. Among the physiological symptoms is white, liquid diarrhea. Similar clinical signs in those infected postnatally, which progresses over 2 to 5 days.

The course of infection and pathological changes

The number of deaths in bird pullorosis reaches 70% and depends on the form of development of the disease.

Acute form of development

It is observed after 3 days or a week and is accompanied by shortness of breath, lack of coordinated movements of chickens, and inactivity of birds. Usually, diseased individuals freeze in a motionless state with closed eyes, paws wide apart, which is often demonstrated by veterinarians as a clear example of a clinical picture in the photo. The temperature rises to 44 ° C. The main symptom of the acute development of pullorosis is profuse liquid diarrhea of ​​white color. The outcome of acute typhoid fever is fatal in most cases, after 10-15 days.

Subacute and chronic development

Such forms of the course of the disease are typical for 2-3-week-old birds and adult chickens. Chickens begin to lose weight, become inactive, and lag behind in development. If you treat birds with antibiotics, most chickens recover from the disease.

In adult broilers, pullorosis symptoms are not observed, the disease proceeds without any special clinical signs. Only periodically it is possible to note a change in egg production towards a decrease. Some individuals are characterized by sluggish states, decreased appetite. With an exacerbation of avian typhus, cases of thirst, shortness of breath are recorded. Laying hens develop peritonitis. With the manifestation of pullorosis in broilers, lameness and the appearance of arthritis are noted, in birds, knee joints swell. Mortality rates among adult broilers are no more than 5% if treated on time.

Pathology

As a result of the developing pullorosis in the body, when embryos, young animals and adults are opened, pathological changes in the internal organs are noted:

• enlargement of the liver, spleen, and gallbladder filled with dark green bile,
• accumulation of white uric acid salts in the rectum,
• the presence of foci of necrosis in the lung tissues, heart,
• inflammatory processes in the intestines,
• the presence of follicular inflammation.

In accordance with the obtained epizootic data, veterinarians make a diagnosis taking into account clinical signs, the age of the bird, and the obtained pathological studies. The final diagnosis is made in the presence of bacteriological studies of fresh bird corpses or in vivo diagnosis of adults by a blood-drop reaction.

Therapeutic and preventive measures

One of the most effective means for the prevention of pullorosis is a bacteriophage administered orally in a dosage of 2 ml. It is entered twice with an interval of 2 days. On the third day, this drug is used as a subcutaneous injection in a volume of 0.5 ml.

Treatment of diseased individuals is carried out using drugs of the antibiotic group, including:

• furazolidone, mixed with feed at 0.04-0.06% for 15 days with repeated treatment after 3-5 days of break,
• less toxic furidin with a dosage of 200 mg per 1 kg of weight, added to feed within 10 days,
• sulfadimezin, widely used as an additive to feed and drinking water, in a volume of up to 1% for 2 weeks, repeated at intervals of 2-3 days,
• complex avidox and colimycin.

Upon detection of cases of pullorosis-typhus and the final diagnosis made by the veterinary service, the decision of the regional executive authority makes a decision to declare an unfavorable situation and begin restrictive measures for breeding chickens and turkey poults, comprehensive treatment and slaughter cleaning are carried out.