Content
- 1 What is pasteurellosis
- 2 Causative agent of pasteurellosis
- 3 Sources and routes of infection
- 4 Symptoms of pasteurellosis in cows and calves
- 5 Diagnosis of 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 farming. It is for this reason that the health of pets requires constant monitoring. Among the most dangerous diseases, it is worth highlighting pasteurellosis in cattle, which is also the most common pathology throughout the world.
When pasteurellosis enters large farms, it can lead to huge losses, including loss of livestock, as well as considerable treatment costs.
What is pasteurellosis
Pasteurellosis is an infectious disease that is contagious. It can spread to many domestic and wild animals. The infection penetrates the body quite quickly and is also rapidly capable of affecting it. If detection is untimely or without taking preventive measures against this disease, death can occur within a day after infection.
The disease affects livestock of any age, but pasteurellosis is considered the most dangerous for young cattle. Calves' immunity is not fully strengthened, so they are more susceptible to pasteurellosis. There is also an increased risk of infection in weak and unvaccinated cows.
Pasteurellosis is widespread throughout the world. Infected cows experience various changes throughout the body, and the normal functioning of internal organs and systems is disrupted. As the disease progresses, it leads to the development of secondary diseases such as pneumonia (even purulent), necrosis of the kidneys and liver, blood poisoning, conjunctivitis and other complications.
Causative agent of pasteurellosis
The disease pasteurellosis is the result of infection of 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. When the animal’s immunity weakens, they enter the bloodstream, spreading throughout the body. As a result, swelling, inflammation and even hemorrhages appear in a variety of 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 to this bacterium. Many disinfectants are also lethal to it.
Sources and routes of infection
Cattle pasteurellosis is 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 an animal that has been ill (cured), since the bacterium remains dormant for a long time in the body of healthy cows.
Exhausted cows with reduced immunity are most vulnerable to pasteurellosis.
Pasteurellosis is characterized by seasonality, so 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 ingested. Therefore, veterinarians divide the disease into forms, each with its own symptoms and treatment features.
Acute form
The first signs of cattle infection in acute pasteurellosis are the following:
- depressed state with loss of appetite;
- rapid breathing and heart rate;
- high temperature reaching 40 degrees or more;
- lack of milk.
Further development of the disease during acute course can be divided into 3 more forms depending on the lesions:
- chest;
- intestinal;
- edematous.
The chest form of acute pasteurellosis in cattle is accompanied by the appearance of pleuropneumonia, as a result of which the following are added to the main symptoms:
- discharge of purulent exudate from the nasal cavity;
- labored breathing;
- liquid stool with blood;
- when listening, the lungs make friction sounds;
- a dry, strong cough appears.
In the case of the intestinal form, the following symptoms can be observed:
- severe thirst accompanied by 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 appearance of the following symptoms:
- cessation of milk production due to the appearance of severe swelling 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 swelling in the cervical region, which leads to the death of the animal.
Subacute form
The subacute form of pasteurellosis in cattle passes more slowly, the disease can last up to 2 weeks. Symptoms at the initial stage are subtle, but as the disease progresses, the signs become more obvious, these include:
- heat;
- hacking cough;
- loss of appetite and weakened state;
- strong thirst;
- nasal discharge, turning from mucous to purulent;
- the appearance of obvious swelling in the head and neck area;
- tearing and inflammation of the eyes.
The subacute form of pasteurellosis often becomes the cause of the development of a disease such as enteritis
Ultra-acute form
Among all forms of bovine 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 its rapid development, the disease is very difficult to identify, and if symptoms can be detected, 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 stool mixed with blood.
Chronic form
The chronic form of pasteurellosis is characterized by a longer period of development, reaching 5 weeks. In this case, the symptoms appear slightly, which is a common cause of death in cattle, since it can be difficult to recognize the signs of the disease in time.
Among the obvious symptoms that you should definitely pay attention to are:
- breathing, which may be difficult;
- refusal to eat, which leads to rapid weight loss;
- swelling of the joints of the limbs;
- the appearance of diarrhea mixed with blood.
Diagnosis of pasteurellosis
Pasteurellosis is an infectious disease, the slightest sign of which requires timely testing. In live cattle, diagnosis is carried out by examining mucus from the nasal cavity and blood tests. The collected smears are examined in detail in the laboratory under a microscope, and bacterial culture is also carried out. In some cases, they even perform special treatment of rodents to determine the degree of virulence of the pathogen. After determining the desired results, the required adequate treatment is selected.
In the case of bovine disease, diagnosis is carried out by laboratory or pathological examination.
When conducting laboratory research, samples taken no later than 5 hours from cows after slaughter or spontaneous death are used. Particles of internal organs such as liver, spleen, lungs or lymph nodes can be used as a sample. The detected pathogen is placed in a nutrient medium, after which its identity is identified.
During a pathological examination, the possibility of infection with pasteurellosis is identified 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 accumulation of blood and lymph under the skin in the tissue;
- lymph nodes are enlarged in size;
- 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 characteristic signs of pasteurellosis are detected in any individual cattle, 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 a developed serum against bovine pasteurellosis is used to combat it.If detected later, this drug is ineffective, so a number of other medications are prescribed.
Having carried out the necessary research to identify the disease and its form, they determine the appropriate drug course of treatment, which is carried out in two directions:
- symptomatic treatment - a sick animal is given drugs that improve the functioning of internal organs and the life support system;
- specific therapy - the cow is given medications against a developing infection.
In addition, they also conduct a course of antibiotics, which help eliminate inflammatory processes in the body and suppress the causative agent of pasteurellosis.
The treatment itself is carried out until the animal recovers completely. In this case, the recovered individual retains immunity to pasteurellosis for approximately 6-12 months.
Vaccine against pasteurellosis in cattle
Emulsified vaccine against pasteurellosis in cattle is the most effective protection for livestock. The specially developed drug 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 administered intramuscularly into the middle third of the neck. The dosage must be determined by a veterinarian.
For calving 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, repeated on the 15-21st day in the 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 acute or hyperacute course of the disease, multiple bruises and hemorrhages can be observed in the area of the liver and heart. But the presence of inflammation in the lungs, swelling 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 due to pasteurellosis in cattle can be seen in the photo below.
Lung of a cow with thoracic form of pasteurellosis (lobar pneumonia)
Preventive actions
In addition to timely vaccination of cattle, the following preventive measures are also an important stage in the fight against pasteurellosis:
- keeping livestock in accordance with all sanitary and hygienic requirements;
- ensuring proper and balanced nutrition (constant monitoring of feed quality);
- periodic disinfection of feeders, livestock housing, as well as related care equipment;
- availability of special clothing for working on the farm (including an individual set for each worker);
- purchasing new livestock only from prosperous, proven farms;
- keeping newly acquired livestock for a month separately from the entire herd (vaccination if necessary).
If, however, the disease could not be avoided and it has become widespread, the owner of the herd must immediately contact the sanitary and epidemiological service of the district to combat 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 to immediately contact a veterinarian to establish a final diagnosis.
