Content
- 1 What is pasteurellosis
- 2 The causative agent of pasteurellosis
- 3 Sources and routes of infection
- 4 Symptoms of pasteurellosis in cows and calves
- 5 Diagnostics of the pasteurellosis
- 6 Treatment of pasteurellosis in cattle
- 7 Vaccine against pasteurellosis in cattle
- 8 Pathological changes in pasteurellosis in calves and cows
- 9 Preventive actions
- 10 Conclusion
Various diseases of cattle can cause enormous damage to the farm. It is for this reason that the health of pets is required to be constantly monitored. Among the most dangerous diseases, it is worth highlighting pasteurellosis in cattle, which is also the most common pathology around the world.
Pasteurellosis, when it enters large farms, can lead to huge losses, consisting in the death of livestock, as well as in considerable costs for treatment
What is pasteurellosis
Pasteurellosis is an infectious disease that is contagious. It can spread to many domestic and wild animals. The infection quickly enters the body, and is also rapidly capable of infecting it. In case of untimely detection or without taking preventive measures against this disease, a lethal outcome can occur within a day after infection.
The disease affects cattle of any age, but pasteurellosis is considered the most dangerous for young cattle. Calves have not fully strengthened their immunity, so they are more susceptible to pasteurellosis. There is also an increased risk of infection in weakened and unvaccinated cows.
Pasteurellosis is common throughout the world. Infected cows undergo various changes throughout the body, disrupting the normal activity of internal organs and systems. Progressing, the disease leads to the development of such secondary diseases as pneumonia (up to purulent), necrosis of the kidneys and liver, blood poisoning, conjunctivitis and other complications.
The causative agent of pasteurellosis
Pasteurellosis disease is the result of damage to an animal by the aerobic bacterium Pasteurella, which is found on the mucous membranes of the gastrointestinal tract. These microorganisms are immobile short oval rods arranged in pairs or in the form of a chain. With the weakening of the animal's immunity, they enter the bloodstream, spreading throughout the body. As a result, edema, inflammation and even hemorrhage appear in various organs.
Today, there are 9 types of Pasteurella bacteria, but 2 of them are considered dangerous for cattle:
- multocida;
- haemolytica.
Regardless of the type, the pathogen is characterized by low resistance to various negative external influences. Sunlight and high temperatures are especially harmful for this bacterium. Many disinfectants are also lethal to her.
Sources and routes of infection
Pasteurellosis of cattle refers to a rapidly spreading disease, the transmission factors of which can be air, feed, water, bedding, various excretions, urine, feces, as well as slaughter products of sick cows. In addition, the pathogen can enter the external environment not only from a sick animal, but also from a sick (cured) animal, since the bacterium stays at rest in the body of healthy cows for a long time.
Weakened cows with reduced immunity are most vulnerable to pasteurellosis.
Pasteurellosis is characterized by seasonality, therefore, most often an outbreak of the disease can be observed from the second half of summer to the end of autumn.
Symptoms of pasteurellosis in cows and calves
Symptoms of pasteurellosis in cattle vary depending on the immune system and age of the animal, as well as the number of bacteria that have entered. Therefore, veterinarians subdivide the disease into forms, where each has its own symptoms and treatment characteristics.
Acute form
The first signs of infection of cattle in acute form of pasteurellosis are as follows:
- depression with loss of appetite;
- rapid breathing and heartbeat;
- high temperature, reaching 40 degrees or more;
- lack of milk.
Further development of the disease in acute course can be subdivided into 3 more forms, depending on the lesions:
- chest;
- intestinal;
- edematous.
The breast form of the development of acute cattle pasteurellosis is accompanied by the appearance of pleuropneumonia, as a result of which the following are added to the main symptoms:
- discharge from the nasal cavity of purulent exudate;
- labored breathing;
- liquid feces with blood;
- the lungs emit friction sounds when listening;
- a dry, strong cough appears.
In the case of the intestinal form, the following symptoms can be observed:
- intense thirst against the background of a complete loss of appetite;
- rapid weight loss;
- blue mucous membranes.
The edematous form of acute pasteurellosis in cattle is one of the most dangerous, since death can occur within 24-48 hours after the onset of such symptoms:
- cessation of milk formation due to the appearance of severe edema in the udder area;
- the appearance of edema in other parts of the body (genitals, limbs, abdomen, and so on);
- rapid and rather difficult breathing (swelling in the neck);
- asphyxia, which appears due to edema in the cervical region, which leads to the death of the animal.
Subacute form
The subacute form of pasteurellosis in cattle is slower, the disease can last up to 2 weeks. Symptoms at the initial stage are subtle, but with the development of the disease, the signs become more pronounced, these include:
- heat;
- hacking cough;
- loss of appetite and a weakened state;
- intense thirst;
- discharge from the nose, passing from mucous membranes to purulent;
- the appearance of obvious edema in the head and neck area;
- tearing and inflammation of the eyes.
The subacute form of pasteurellosis often causes the development of a disease such as enteritis
Hyperacute form
Among all forms of cattle pasteurellosis, the most dangerous is hyperacute, in which an infected individual can die within 12 hours from the end of the incubation period. Due to the rapid development of the disease, it is very difficult to identify, and if it is possible to detect symptoms, then they are of the following nature:
- high temperature exceeding 40 degrees (can reach up to 42);
- the appearance of severe swelling in the neck, chest, and internal organs;
- loose stools with blood impurities.
Chronic form
The chronic form of pasteurellosis is characterized by a longer developmental period, reaching 5 weeks. At the same time, the symptoms appear insignificantly, which is a common cause of the death of cattle, since it is difficult to recognize the signs of the disease in time.
Among the obvious symptoms that you should definitely pay attention to are:
- breathing that may be difficult;
- refusal to eat, which leads to rapid weight loss;
- swelling of the joints of the limbs;
- the appearance of diarrhea with blood impurities.
Diagnostics of the pasteurellosis
Pasteurellosis is an infectious disease, at the slightest sign of which timely tests are required. In live cattle, diagnosis is carried out by examining mucus from the nasal cavity and a blood test. The removed smears are examined in detail in the laboratory under a microscope, and bacterial culture is also carried out. In some cases, even special treatment of rodents is performed to identify the degree of virulence of the pathogen. After determining the desired results, the required adequate treatment is selected.
In the case of cattle pestilence, diagnosis is carried out by laboratory or pathological research.
When conducting laboratory research, samples are used, taken no later than 5 hours from cows after slaughter or self-death. Particles from internal organs such as the liver, spleen, lungs or lymph nodes can be used as a sample. The detected pathogen is placed in a nutrient medium, after which its affiliation is identified.
In pathological examination, the possibility of infection with pasteurellosis is detected on the basis of changes in internal organs and life support systems. The following signs indicate a positive result:
- hemorrhage in internal organs (heart, lungs, intestines);
- the presence of an accumulation of blood and lymph under the skin in the fiber;
- the lymph nodes are enlarged;
- inflammation of various parts of the gastrointestinal tract.
Timely and correct diagnosis of pasteurellosis is the basis for its successful treatment.
Treatment of pasteurellosis in cattle
If any individual cattle is found to have characteristic signs of pasteurellosis, the cow is immediately isolated from other domestic animals. It is placed in a dry, warm room with good ventilation. In this case, the animal is transferred to a special diet with the addition of vitamins, minerals and other nutrients to improve well-being. If the disease is detected at an early stage, then the developed serum against cattle pasteurellosis is used to combat it. With a later detection, this drug is ineffective, therefore, a number of other drugs are prescribed.
Having carried out the necessary research to identify the disease and its form, the appropriate drug course of treatment is determined, which is carried out in two directions:
- symptomatic treatment - a sick animal is given drugs that improve the functioning of internal organs and life support systems;
- specific therapy - the cow is injected with drugs against the developing infection.
In addition, they also conduct a course of antibiotics that help eliminate inflammatory processes in the body and suppress the causative agent of pasteurellosis.
The treatment itself is carried out until the animal is fully recovered. In this case, the recovered individual retains immunity to pasteurellosis for about 6-12 months.
Vaccine against pasteurellosis in cattle
Emulsified vaccine against pasteurellosis in cattle is the most effective protection for livestock. A specially developed preparation contains an emulsion and an emulsifier, thanks to which the animal acquires temporary immunity against the disease. The period of its preservation can reach from six months to a year.
The vaccine is injected intramuscularly into the middle third of the neck. The dosage must be determined by the veterinarian.
For heifers and pregnant cows, a one-time injection of the emulsion is suggested 25-45 days before calving. Calves are vaccinated once in the case of vaccinated parents on the 20-25th day of life, and twice on the 8-12th day with a repeat on the 15-21st day in case of unvaccinated parents.
Pathological changes in pasteurellosis in calves and cows
Pathological changes in internal organs during pasteurellosis in calves and cows directly depend on the form of this disease. Thus, in the acute or hyperacute course of the disease, multiple bruises and hemorrhages can be observed in the region of the liver and heart. But the presence of inflammation in the lungs, edema of many internal organs and necrosis of the kidneys or liver is a consequence of the chronic form of pasteurellosis.
An example of changes in internal organs during pasteurellosis in cattle can be seen in the photo below.
Cow lung with breast pasteurellosis (lobar pneumonia)
Preventive actions
In addition to the timely vaccination of cattle, also an important stage in the fight against pasteurellosis is the implementation of such preventive measures:
- keeping livestock in accordance with all sanitary and hygienic requirements;
- ensuring correct and balanced nutrition (constant control over the quality of feed);
- periodic disinfection of feeders, premises for keeping livestock, as well as related care equipment;
- availability of special clothing for working on the farm (including an individual set for each worker);
- the acquisition of a new livestock only in prosperous, proven farms;
- keeping newly acquired livestock for a month separately from the whole herd (if necessary, vaccination).
If, nevertheless, the disease could not be avoided, and it became widespread, the owner of the herd should immediately contact the sanitary-epidemiological service of the district to fight the infection and prevent its further spread to nearby farms.
Conclusion
Pasteurellosis in cattle is a very dangerous infection that requires timely identification and treatment. In this case, it is advisable, when identifying the first symptoms, not to waste time on long-term observation, but immediately contact a veterinarian to establish a final diagnosis.
