Pig pasteurellosis: symptoms and treatment, photo

Pig pasteurellosis is one of those diseases that can put an end to all the farmer’s calculations for making a profit from pig production. The most susceptible to this infection are piglets, which are usually raised specifically for the sake of sale. Adult pigs also get sick, but less often and tolerate the disease more easily than piglets.

What is the disease “pasteurellosis”

This bacterial disease is considered common to many animal species, including humans. The latter is usually infected with Pasteurella from pets. The causative agent of the disease in pigs is the immobile bacteria Pasteurella multocida types A and D and Pasteurella haemolytica. Symptoms of pasteurellosis vary widely depending on the species of animal from which the bacterial culture was obtained.

Pasteurella has 4 serogroups classified: A, B, D, E. All these groups are similar in appearance and antigenic properties. Pasteurella look like motionless oval sticks 1,5-0,25 microns long. They belong to Gram-negative bacteria. Dispute does not form. All varieties of Pasteurella grow on the same nutrient media, preferring the presence of blood in the broth.

Pasteurella is not highly resistant:

• when dried, they die after a week;
• in manure, cold water and blood can live up to 3 weeks;
• in corpses – 4 months;
• in frozen meat they remain viable for up to a year;
• when heated to 80 ° C, they die in 10 minutes.

Bacteria are not resistant to disinfectants.

What is dangerous disease

Pasteurellosis usually develops along the path of epizootics. Shortly after infection of one individual, the entire population of pigs on the farm falls ill. Most often in piglets, an acute and hyperacute course of pasteurellosis is observed. Adult pigs have a chronic course. Due to the nature of the course of chronic pasteurellosis, the animal is more often treated for other diseases, contributing to the spread of pasteurella.

Causes and ways of infection

Bacteria are excreted along with the physiological fluids of a sick animal. Bacillus carriers can be outwardly healthy, but recovered pigs. Infection occurs by direct contact of animals by airborne droplets. Also, a healthy pig can become ill with pasteurellosis through water and feed contaminated with feces or saliva. Carriers of pasteurellosis can be blood-sucking insects.

Contribute to the preservation of bacteria in the external environment:

• untimely cleaning of machines, which contributes to an increase in humidity as a result of urine evaporation;
• low-quality feed that reduces the immunity of pigs;
• high crowding of animals, due to which pigs experience stress, also leading to immune suppression;
• lack of vitamins in the diet.

There were also outbreaks of pasteurellosis after vaccination against plague and erysipelas.

Symptoms of the disease in different forms

Pasteurellosis is a “variable” disease. Its signs vary not only depending on the type of course of the disease. In total, there are 4 types of the course of the disease:

• hyperacute;
• sharp;
• subacute;
• chronic.

They differ in the length of time that passes from the moment the first symptoms appear to the death of the pig. How pasteurellosis will proceed in each particular pig depends on the virulence of the bacteria and the resistance of the animal’s immune system to the pathogen.

Super sharp shape

With a hyperacute form of pasteurellosis, the death of pigs occurs after a few hours. Signs of a hyperacute form:

• temperature 41-42 ° C;
• thirst;
• refusal to feed;
• oppressed state;
• disorders in the work of the cardiovascular and respiratory systems;
• possible diarrhea with an admixture of blood and mucus.

The progress of the disease is very fast. Before the death of the pig, symptoms of heart failure, swelling of the head are observed. Pathological examination reveals pulmonary edema.

Acute form

The symptoms of the acute form are the same as those of the hyperacute form. Before death and during research, the same signs are found. Unlike hyperacute, with this course of pasteurellosis, death occurs after a few days.

Subacute form

The subacute and chronic course of pasteurellosis are also similar. In both cases, the disease is characterized by fever and localization of the process in individual systems of the pig’s body. Depending on the localization of bacteria, pasteurellosis is divided into 3 forms:

Intestinal:

• debilitating diarrhea with dark brown or reddish stools;
• admixture of blood in manure;
• thirst;
• refusal to feed;
• exhaustion;

Thoracic:

• serous, later mucopurulent discharge from the nose;
• possible blood in the nasal discharge;
• labored breathing;
• cough;

edematous:

• inflamed swelling of the eyelids;
• swelling of the tongue and larynx;
• swelling of the subcutaneous tissue on the neck, abdomen and legs;
• difficulty swallowing;
• hard breath;
• secretion of thick saliva;
• heart failure.

Because of the wide variation in symptoms of pasteurellosis, it is easy to confuse the disease with other infections.

Chronic form

Symptoms and localization of bacteria in chronic course are similar to subacute. But since death occurs after a few weeks, more pathological changes have time to accumulate:

• depletion of corpses;
• fibrinous-hemorrhagic inflammation of the intestine;
• fibrinous-purulent inflammation with necrosis in the lungs.

Since in the subacute and chronic course of pasteurellosis, the symptoms in pigs depend on the localization of bacteria, treatment is prescribed only after it has been differentiated from plague, erysipelas and salmonellosis.

How the disease is diagnosed

If pasteurellosis is suspected, parts of the corpses of dead pigs are handed over to the laboratory for research. The whole carcass is not needed in the laboratory, since pasteurellosis affects the internal organs. At autopsy, lesions are found:

• GIT;
• light;
• heart muscle;
• spleen;
• liver.

In the photo, a lung of a pig that has fallen from pasteurellosis.

For research in the laboratory, in addition to the lungs and spleen, you can also send:

• brain;
• glands;
• lymph nodes;
• tubular bones.

Upon receipt of the biomaterial in the laboratory, pasteurella is also isolated and a bioassay on mice is carried out.

Small pieces of organs 5×5 cm in size are handed over for analysis. Material is suitable for research only from those animals that did not have time to receive antibiotics during their lifetime.

Treatment of pasteuriosis in pigs

Sick pigs are separated and placed in a warm dry room. Provides high quality nutrition. Treatment is carried out in a complex manner, using antibacterial drugs and means for symptomatic treatment. Of the antibiotics, those belonging to the penicillin and tetracycline groups are preferred. The antibiotic is used according to the instructions for the drug. Some long-acting medications can be used once, but this must be indicated in the instructions. Sulfonamides are also used.

To enhance immunity, serum against pasteurellosis of pigs is used. It is administered once intramuscularly or intravenously at a dose of 40 ml per animal.

On sale you can find whey of Belarusian and Armavir production. It follows from the instructions that the difference between these two drugs is in the timing of the formation of passive immunity and the timing of protection against pasteurellosis.

After applying the serum of Armavir production, immunity is formed within 12-24 hours and lasts for 2 weeks. The Belarusian immunity is formed immediately after application, but lasts only 1 week.

If there are diseased animals on the farm, serum from pig pasteurellosis is also used as a prophylactic for animals that look healthy. Clinically healthy piglets under a sick sow are injected with serum at a therapeutic dose.

If pasteurellosis is detected on a farm, the farm is quarantined. The import and export of pigs outside the farm is prohibited. Carcasses of forcedly slaughtered pigs are sent for processing to a meat processing plant.

Prevention

Prevention of pasteurellosis is, first of all, compliance with veterinary rules. Newly acquired pigs are placed in a 30-day quarantine. The livestock is completed from farms free from pasteurellosis. Contact between pigs from different holdings is not allowed.

Pigs do not graze on waterlogged pastures, where pasteurellosis pathogens can persist for six months. Carry out regular deratization of premises. Food is stored in sealed containers inaccessible to rodents.

In areas unfavorable for pasteurellosis, mandatory vaccination of pigs is carried out twice a year. On holdings where pasteurellosis has been reported, new pigs must either be vaccinated at the supplier during the year or vaccinated during quarantine. The introduction of unvaccinated animals into the herd is allowed no earlier than one year after the improvement of the economy.

Vaccine against pasteurellosis

Serum is made from the blood of recovered or vaccinated animals. It contains antibodies to pasteurellosis and acts immediately after administration.

The vaccine is a preparation containing Pasteurella bacteria neutralized with formalin. The vaccine cannot be used on a farm where pasteurellosis has already been detected. In this case, vaccination can provoke the development of the disease.

In a farm located in a disadvantaged area or previously experienced an outbreak of pasteurellosis, vaccination of pigs is mandatory. Vaccinate only clinically healthy animals.

Vaccination is carried out twice. The formation of immunity occurs 20-25 days after the last vaccination. Immunity is maintained for 6 months.

Vaccinated sows transfer immunity to piglets. The action of such “milk” immunity lasts 1 month, therefore, from the 20-25th day of life, piglets are vaccinated twice with an interval of 20-40 days. Injections are made intramuscularly in the neck. The dose for a piglet is 0,5 ml.

Pregnant uterus is given a single vaccination with a double dose (1 ml) 1-1,5 months before farrowing. The vaccine is administered intramuscularly in the upper third of the neck.

Conclusion

Pig pasteurellosis is a disease that can be avoided if the conditions for keeping animals and their feeding rations are observed. Timely vaccination will significantly reduce the likelihood of pasteurellosis, since the causative agents of this infection are the same in all animals. You cannot count on the fact that a pig will not become infected from a chicken or a rabbit.