In young cattle, the immune system is still weak, and their body is susceptible to attacks by pathogenic microorganisms. The causative agents of paratyphoid fever in calves are bacteria of the genus Salmonella. They are resistant to most antibiotics, release many toxins during their life processes, and negatively affect the immunity of a sick animal. The disease is accompanied by profuse diarrhea; if left untreated, the calf dies.
Description of the disease
Paratyphoid is an infectious pathology of bacterial origin.Pathogenic bacteria infect the intestines of young individuals and cause an acute inflammatory process. The causative agent of paratyphoid fever is Salmonella Gertner, which causes acute food intoxication not only in animals, but also in humans. Toxic substances released by bacteria accumulate in the soft tissues of calves, so the meat of infected animals must be disposed of.
A person who eats veal contaminated with salmonella becomes severely poisoned. Salmonella is a rod-shaped microorganism with rounded edges. In the external environment, it is active, resistant to negative factors, and does not respond to high temperatures and most antibiotic substances. But it is susceptible to antiseptics that contain Lysol (cresol soap) and creolin.
Causes
The occurrence of paratyphoid fever is facilitated by non-compliance with livestock keeping conditions.
The main causes of paratyphoid infection in calves:
- crowded conditions in a cramped stable;
- insufficient lighting;
- unsanitary conditions;
- poor quality feeding, use of spoiled products.
The disease is aggravated by low temperature in the barn, due to which the calves’ immune system is weakened. But normalizing temperature conditions does not help if animals are already infected, since salmonella is immune to temperature changes.
Bacteria enter the body through the respiratory tract. And in the external environment, salmonella appears in the feces and urine of sick individuals. The infection can enter directly into the calf's digestive tract if it eats contaminated feed or drinks water.
Forms and symptoms of paratyphoid fever in calves
The incubation period of paratyphoid fever lasts from 5 days to 2 weeks. The infection affects the nervous system, digestive tract, and later, in the absence of proper treatment, joints.
Paratyphoid fever in calves occurs in three forms.
Acute form
It is observed in calves less than a month old.
The main symptoms of the acute form:
- fever, in which body temperature rises to 40-41 °C;
- foul-smelling diarrhea with mucous inclusions, sometimes with blood streaks;
- weakness, impotence, inability of the calf to rise from the litter;
- conjunctivitis, accompanied by profuse lacrimation;
- rhinitis, flow of mucous mass with serous impurities from the nasal passages of the calf;
- cough.
Conjunctivitis and runny nose appear a few days after diarrhea. Rhinitis is not observed in all cases, and the calf usually begins to cough when the owner opens the barn door and lets cool air in. With advanced paratyphoid fever, the limbs swell, convulsions are observed, and consciousness is depressed. But until death, the pet eats well.
If, during the acute form of paratyphoid fever, the body temperature fluctuates frequently, then the calf’s probability of survival is high. If your pet suffers from profuse diarrhea, the fever does not go away, and lethargy and weakness increase, then there is no doubt that he will die soon.
Subacute form
It is detected in calves that have reached the age of one month. Lasts 3-5 days.
Symptoms of subacute paratyphoid fever:
- weak appetite;
- short-term fever, in which the temperature rises to 40-41 °C;
- mild diarrhea;
- rhinitis with clear discharge from the nasal passages;
- slight cough, wheezing breathing.
Coughing and wheezing are not always observed. If there are no aggravating pathologies, the pet recovers.
Chronic
Acute paratyphoid fever becomes chronic.Intestinal inflammation gradually subsides, diarrhea stops, but the infection moves to the lung tissue. Sick the calf is breathing heavily and quickly, sometimes with wheezing and whistling. When listening during inhalation and exhalation, wheezing is heard; when percussing (tapping), dullness of sounds is noted.
The duration of chronic paratyphoid fever is up to 2 months. The likelihood of death in the absence of proper treatment is high, since the pet’s body is in an exhausted state.
Diagnostics
To identify pathogenic microorganisms, an agglutination reaction is carried out in the laboratory - the precipitation of stuck together bacteria under the influence of antibodies in an electrolyte environment. The results of the analysis are often overestimated not only in patients, but also in nearby healthy animals. An accurate diagnosis is made by a veterinarian after an autopsy of the dead calf. What an autopsy shows for different forms of paratyphoid fever is indicated in the table.
| Form of the disease | Affected organs | Changes |
| acute | mucous membranes | hemorrhages |
| liver and spleen | swollen, with hemorrhages | |
| lungs | deep red, filled with blood, compacted in some places | |
| subacute | heart muscle | in most cases degenerate |
| stomach and intestines | inflamed | |
| liver and spleen | covered with gray spots | |
| lungs | red, with tissue compaction and blood clots in different places, the bronchial tree is inflamed, there are mucous and purulent accumulations inside it, the lymph nodes near the lungs are swollen and reddened | |
| chronic | intestines, liver, spleen | changed in the same way as in the acute form of the disease |
| lungs | abundantly strewn with necrotic spots, the bronchi are clogged with purulent mass, the mucous membrane is inflamed, with many hemorrhages |
Treatment methods
The owner must immediately isolate sick animals and disinfect the barn. The most reliable drug for paratyphoid fever is “Bacteriophage”. Sold in 20 ml bottles, 4 pieces per box. The calf is given orally 3 times a day, 2.5 bottles for mild paratyphoid, 5 bottles for severe.
Effective drugs include the Clamoxil suspension and Terramycin injection solution. The first drug is injected into the muscle, the dose is 1 ml per 10 kg of body weight. In case of severe paratyphoid fever, the injection is repeated after 2 days. The second drug is much stronger in effect; it is injected once into the muscle in a similar dosage.
You can also treat the calf with oral medications “Sulgin”, “Levomycetin”, “Furazolidone”. They are added to the feed 3 times a day, the dose is 3-8 mg per 1 kg of body weight. Drugs can be alternated. A pet undergoing treatment is given niacinamide (vitamin B3), daily dose – 100 mg per 1 kg of feed. A calf with paratyphoid fever is kept in quarantine for 3 months.
Possible consequences
In a sick pet, brain tissue swells and hemorrhages occur in the organs of the reproductive and urinary systems. In some cases, pathological changes in the liver and spleen are possible. The main blow of the infection falls on the intestines, inflammation begins, and the functional state of the mucous tissues lining the intestinal tube is disrupted. In advanced cases, the calf experiences cramps in the limbs - this is a sign of damage to the joint tissues.
In the acute form, calves in many cases die within 1-2 days after the onset of symptoms due to blood poisoning.With proper and timely treatment, the mortality rate of young animals can be reduced to 3%, or even save all pets.
Vaccination and preventive measures
The main preventive measure is maintaining cleanliness. The barn needs to be regularly cleaned and disinfected, the bedding changed, and the feeders and bowls from which the calves eat should be washed. It is recommended to use lime mortar as a disinfectant. The room should be dry, ventilated, spacious. It is important to keep livestock equipment clean and to feed the animals well.
The second preventive measure is livestock vaccination. Cows can be carriers of paratyphoid fever, they infect newborn calves, but in those calves the immune system has not yet strengthened, the body is weak, and cannot fight the infection. Therefore, a calf born to an unvaccinated cow is immediately isolated. Livestock are vaccinated against paratyphoid fever with a concentrated formol-alum vaccine. The dosage and frequency of vaccinations is determined by the veterinarian. You cannot treat and vaccinate animals at your own discretion; all actions must be coordinated with a veterinary specialist.
