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Salmonellosis in calves is a widespread disease that almost all farms face sooner or later. Basically, the disease affects young animals under two months of age, since adults have higher resistance to various infections. The danger of salmonellosis is that it can be transmitted not only to other animals, but also to humans.
What is salmonellosis
Salmonellosis is an infectious disease that can affect many species of animals and birds. The disease is caused by Salmonella bacteria - microorganisms that are resistant to adverse environmental conditions, so even equipment for working with animals can cause a re-outbreak of infection. Also, premises where sick calves were kept may remain contaminated for a long time.
The peak period of the disease occurs in the spring - the time of mass calving, but in general, salmonellosis can develop in cattle at any time of the year. Small calves, especially newborns, are very vulnerable to this disease.Symptoms of salmonellosis can appear in them as early as the 10th day after birth. The higher the unsanitary conditions of keeping cattle, the greater the likelihood of an outbreak of salmonellosis in the herd.
Pathogenesis of salmonellosis
The carriers of salmonellosis are rodents and adult cows, in which the disease is most often asymptomatic. The infection is usually transmitted to small calves through milk or contaminated equipment, however, the conditions of the barn also play an equally important role. If the premises are rarely cleaned, the likelihood of developing salmonellosis increases, as it can be transmitted through the urine and feces of cattle. First of all, the infection affects individuals with weakened immune systems - calves that have recently been ill with something, or animals that are deficient in vitamins. In the latter case, cows receive low-quality or extremely monotonous feed.
Symptoms of salmonellosis may appear the next day after infection or two weeks later. The disease occurs in mild, acute and chronic forms, however, their symptoms are largely similar.
Salmonellosis causes weakness and apathy in affected animals
Symptoms of salmonellosis in calves
Signs that calves have been affected by salmonellosis include the following changes in the behavior and physiology of animals:
- They become lethargic and apathetic, sleeping almost all the time or just lying down.
- Transparent mucus discharges abundantly from the nose.
- Animals stop eating or eat very little.
- Sometimes 2-3 days after infection, sick calves experience a change in stool - it becomes liquid and frequent, and diarrhea begins. There is gray mucus and blood in the stool.
- Acute salmonellosis is characterized by a high temperature - it can increase to 40-42°C.
- If the disease is severe, calves experience frequent urination. The process becomes painful, and there is blood in the urine.
- In the acute form of salmonellosis in sick animals, cough, runny nose and conjunctivitis are additionally noted. If treatment of infection is delayed, calves may develop a fever.
The chronic form of salmonellosis develops if the disease is not detected on time or treatment is simply taken too late. It is characterized by the same symptoms, but additionally develops arthritis and respiratory diseases. Diarrhea disappears over time, sick individuals regain their appetite for a short time, however, weight loss is noted.
The chronic form can last up to two months.
Diagnosis of salmonellosis
Diagnosis of salmonellosis in calves is complicated by the fact that the characteristic signs of infection are similar to the symptoms of other diseases:
- colibacillosis (the cubs are less than 10 days old, sepsis and serous inflammation of the lymph nodes are present);
- pasteurellosis (lobar pneumonia is present);
- dyspepsia (calves are less than 10 days old, sepsis is not observed);
- streptococcal infection (diagnosed as pericarditis, pleurisy).
The diagnosis is made after a comprehensive examination of the calves. To do this, it is necessary to send blood and feces taken from sick animals to the laboratory.
Treatment of salmonellosis in cattle
The first thing to do after detecting salmonellosis in calves is to separate the sick individual from the rest of the herd to prevent the spread of the disease. After this, complex treatment is started using antibiotics and auxiliary drugs. Most often, a veterinarian prescribes the following medications for salmonellosis:
- Levomycetin veterinary in tablets for oral use. The exact dosage is calculated by the veterinarian, taking into account the weight of the calf. The recommended course of the drug is 3-4 days with a frequency of use three times a day.
"Levomycetin" is available in different forms, however, for the treatment of cattle, a veterinary version in tablets is used
- "Terramycin". The course of treatment lasts approximately 5-6 days, for every kilogram of the animal’s weight there is 0.02 g of the product. Frequency of use – 2-3 times a day.
"Terramycin" is produced in the form of an aerosol and solution
- Polyvalent antitoxic serum. The action of the drug is aimed at strengthening the immune system and preventing disease in calves and adult cows. The serum is administered intramuscularly, the dose is calculated by the doctor.It is recommended to divide the daily dose into several injections, between which there is usually a break of 3-5 hours.
All injections are carried out using disposable syringes, which are prohibited from being reused.
Expired products should not be used to treat salmonellosis in calves. They can cause harm to the health of animals.
Vaccine against salmonellosis in calves
The salmonellosis vaccine is the most effective measure of protection against this disease. It is recommended to vaccinate calves 1-2 days after birth. The vaccine will not help already infected individuals, but in healthy animals there is a general strengthening of the immune system.
The drug begins to act on average on the 14th day. 10 days after the first vaccination, the second one is usually given. Adult cows are given the vaccine a month and a half before calving. In this case, the newborn calf is vaccinated only once and a little later - 15-20 days after birth.
If a veterinarian diagnoses any ailment in young animals, vaccination should be delayed a little.
Pathological changes in salmonellosis in calves
The acute course of the disease can affect the organs of the gastrointestinal tract, as a result of which gastroenteritis and sepsis are diagnosed in calves. With chronic salmonellosis in sick individuals, the respiratory tract, digestive organs and immune system are affected. Acute catarrhal inflammation begins in the rectum and small intestine of affected calves.
At the age of two months, animals may develop exudative inflammation. The liver of calves enlarges, necrosis and Salmonella nodules form in it.
Preventive actions
Salmonellosis can quickly spread to a large part of the herd if not treated promptly. However, it is even better to prevent an outbreak of the disease at all - to do this, it is enough to follow the most basic rules for keeping cattle:
- The barn must be cleaned at least once a week. It is not enough just to remove dirt - it is also advisable to use various disinfectants. After each bowel movement, the floor in the room where an adult animal or calf is kept must be washed.
- Under no circumstances should cattle be kept in cramped conditions. If animals are crowded close together in a small space, salmonellosis spreads very quickly. In addition, with such maintenance it is necessary to clean the barn much more often.
- A quick inspection of the entire herd is recommended every day. This increases the chances of noticing the first symptoms of salmonellosis in time and starting timely treatment before the disease spreads to other animals.
- It is very important to take cows and calves out for exercise regularly. It is necessary to install good air ventilation in the barn itself.
- To prevent the presence of rodents in the room, which are also carriers of infection, food remains are removed after each feeding. You cannot store food in bags in the same room.
- Drinking water for calves should be at room temperature. It is changed regularly - dirty drinking bowls often become sources of infection.
The risk of disease is lower if cattle are kept in a sufficiently spacious room
In farms that are unfavorable for salmonellosis, it is recommended to vaccinate pregnant cows. To do this, they are injected with a formula-alum vaccine against paratyphoid fever twice with a two-month interval.
Adequate nutrition is also of great importance for the health of cattle. The lack of certain substances in the body of animals weakens their immunity, as a result of which they are not able to resist the disease. In the summer, calves should receive a sufficient amount of fresh feed; they should not be fed rotten or rotten hay. With the onset of frost, the herd is released for walking carefully, since the grass already has time to freeze. From time to time, calves need to be given vitamin supplements.
Conclusion
Salmonellosis in calves is a rather dangerous infectious disease, but with timely treatment the animals recover quickly. After an outbreak of infection, it is necessary to thoroughly disinfect all equipment that was used to work with calves, and the room where sick individuals were located. During the treatment process, it is also important to consider your own safety - salmonellosis can be transmitted to humans.
You can learn more about the symptoms, course of the disease and its treatment from the video below:
