Today, the swine flu virus is a real disaster for pig farms. Every year it causes enormous damage to farmers. Although adult pigs rarely die from it, they are seriously ill, lose weight and lose productivity. With the young, things are much worse - from 10 to 60% of pigs do not survive. In addition, the pathogen can be transmitted to humans and other animals, it spreads very quickly. In this article we will tell all the details about this pathology.
History of discovery, general information about the disease
Swine flu (otherwise known as influenza) is a respiratory illness. It is acute and usually manifests itself during cold weather: late autumn, winter, early spring.
The disease was first recorded in 1918 in the United States. The H1N1 virus itself was discovered by American scientist Richard Shoup. It happened in 1930. At that time, only pigs were affected by the disease, and this has been the case for half a century.
Decades later, the virus mutated and began to spread to humans. It is common in many countries of the world. So, it is found in Canada, USA, Kenya, Mexico, Japan, China, other countries of Asia and Europe. Few people know, but it is H1N1 that is directly related to the famous epidemic of the Spanish flu of 1918.
Of the later large-scale pandemics, California can be cited. Then, in 2009, thousands of people around the world became victims of swine flu. Fortunately, such outbreaks are rare among the human population. Unlike pigs.
Pathogen and its subtypes
Swine flu virus is not just H1N1. There are other subtypes: H3N1, H1N2, H3N2. However, animals usually become ill only from strains H1N1 and H3N2.
The causative agent of swine flu is referred to as orthomyxovirus, to which all influenza viruses belong. They affect the airways. A virion, a microbe particle that lives outside the body and carries genetic material, contains fats, protein, polysaccharides and RNA fragments. In sick animals, the pathogen is found in sputum, in the tissues of the trachea, bronchi, lungs, in the lymph nodes, nasal secretions.
If the disease is severe, the virus penetrates into other organs. Then it can manifest itself in urine, bile, and blood. The pathogen is not able to survive for a long time in the air and in another environment outside the body. At a temperature of 20-25 degrees, heat can infect animals during the day. At 60 degrees Celsius lives just 20 minutes.
In nature, wild animals and birds suffer from swine flu quite rarely (with the exception of boars), but laboratory experiments show that the virus is perfectly transmitted and reproduces in the body of rodents, chickens, hedgehogs and dogs.
Pathways of the pathogen in vivo
The spread of the virus is carried out not only at the expense of sick animals, but also by simple carriers, who may not have symptoms of the disease. The most common infection occurs through airborne droplets. Like any flu, swine most actively spreads when animals are kept in crowdedness.
At the same time, there are other ways of transmission of the pathogen. In affected farms, these are the excretions of sick pigs and the products of their slaughter and even feed.
Also, the virus persists in parasites that live in the organs of pigs and are released into the environment. In this case, the animal does not show signs of illness. Some of the parasites, such as metastrongilids, enter the earth and then enter the body of ordinary earthworms.
Thus, they become carriers of swine flu. Pigs digging in the ground can eat earthworms and become infected.
In earthworms and parasites, the pathogen can live safely for two years, transmitted during breeding. Although the virus does not live long in the open, it is able to maintain pathogenicity in the frozen state for up to four years.
Pathogenesis, disease development mechanism
Since animals usually become infected by airborne droplets, and the disease itself is respiratory, the virus enters the body in the respiratory tract. Getting into the trachea, bronchi, the pathogen multiplies, affecting the mucous surface. Tissue inflamed. The upper layer dies off as the disease progresses, and the particles of dead tissue come out during coughing.
The emergence and development of the disease contribute to adverse factors - low temperature and dampness. Under such conditions, pigs in the bronchi and the trachea produce exudate more actively (fluid released during inflammation in the tissue from small vessels), and it is here that the pathogen feels best.
Swine flu in pigs is also accompanied by intoxication. Fruits of the virus poison the body, causing problems with the heart and nervous system. Small blood vessels often lose elasticity, become thin and burst. Hence the bruises on mucous membranes and nosebleeds in sick animals.
Symptoms and course of the disease, the probability of death
While fixing swine flu, the symptoms are the same as in many other viral respiratory diseases:
- runny nose, sneezing and coughing in animals;
- wheezing in the lungs, bronchi;
- swollen lymph nodes;
- high, up to 41-42 degrees, temperature;
- weakness, lack of appetite;
- breathing problems.
As the malady develops, the symptoms of swine flu become worse. Drowsiness and weakness can reach such an extent that the animal does not respond to its surroundings. The bluish-pale color of the abdomen or other parts of the body occurs when the pig is sick for more than a day. It is explained by a violation of blood circulation due to the effect of the virus on the cardiovascular system.
If the pig as a whole was healthy and its immunity is strong enough, she recovers after 7 or 10 days. If the animal is weak, complications arise, including blood poisoning. Then it dies. The high percentage of deaths in piglets is due to the lack of formation of the immune system and the body. Sows in pregnancy are prone to miscarriages.
Sometimes the flu is almost symptom free. This is an atypical form.
How to diagnose this disease: research and analysis
Applying to a veterinarian and conducting laboratory tests are mandatory if you suspect swine flu in animals.
Signs of swine flu are similar to many other respiratory diseases, and therefore only a specialist can diagnose.
There are two ways to establish the correct diagnosis. In the first case, samples are taken from the nose of sick animals - swabs or scrapings. They are combined with various substances, serums and, thus, isolate the pathogen and accurately determine the strain of the virus.
In the second case, the subject of the study is the blood of infected pigs. At the same time, in the laboratory, it is not the pathogen that is isolated, but antibodies produced by the body. If there are too many of them, this clearly indicates infection and the need for further analysis. Then they determine the specific "culprit" of the disease. Of course, when making a diagnosis, the obvious symptoms of the disease are taken into account.
It is worth remembering that it is better not to carry out any independent manipulations with sick animals. Although people rarely get infected by pigs, the virus can still be transmitted through the air or with secretions - there are such cases.
Treatment: sulfonamides, vitamins and favorable conditions
In swine flu treatment is non-specific, there are no special drugs for it. Used well-known, familiar medicines.
First and foremost, you need to create good conditions for animals so that the body can fully fight. Pigs provide dryness and heat, protect from drafts. The litter should be changed as often as possible, it is necessary to air the room carefully, but it is necessary. Well, if you can disinfect with ultraviolet light. Diet easy: jelly, liquid cereals.
You can use sulfa drugs from swine flu. For example, take one liter of a solution of hexamethylenetetramine (40%), mixed with 50% calcium chloride in an amount of 10 ml. The solution is administered intravenously 1 or 2 times a day, 10 cubes.
To reduce the body's intoxication, atoxyl is injected under the skin of pigs. It acts not only as an enterosorbent, but also as a healing, antimicrobial agent. Dosage - 10 ml of 10% solution.
Additionally prick trivitamin - once in 2 days, intramuscularly. Also injected ascorbic acid, vitamins of group B - to maintain the body.
Before self-medication, contact your veterinarian.
Use of antibiotics and antibacterial drugs
The use of drugs that suppress pathogens is necessary for the prevention and control of complications of influenza. It is necessary to treat swine flu, including antibiotics in the scheme.
Streptomycin (10-20 thousand units of action (ED) per kg of weight), oxytetracycline (15 thousand ED), dihydrostreptomycin or monomitsin (10 thousand ED) will do. These drugs are administered intramuscularly. With food, give chloramphenicol tablets at the rate of 20-35 ml per kg of pig weight, or 0.02-0.03 g per kg of norsulfazole. The treatment usually lasts 5-7 days, provided that the medication is given 1-3 times a day.
Once a day for 4-6 days the antibiotic bicillin-3 is intramuscularly injected. With food, you can give tetracycline, farmazin, trimetosul, rovatezin. The dosage is respectively 20, 20, 125 and 100 ml per 1 kg of weight.
Since the respiratory tract is affected by swine flu, drugs in the form of aerosols are effective. They are also used when piglets are in the room. Disinfectant Balsam-ECB is used - 0.3 ml per cubic meter of area. Chlorine-turpentine, esteryl, lactic acid, aluminum iodide, acetic acid, sodium hypochloride, and chloramine are also sprayed.
The exact dosage of all drugs, based on the age and weight of the pigs, you can always find in the instructions for drugs, or consult with a veterinarian.
Immunity after illness and artificial immunization of livestock
Animals that have recovered become immune to swine flu, but it persists for only a few weeks. At this time, the pig can not get sick, even attempts to infect her purposefully will not lead to anything.
In many countries, Suvaxyn Flu-3 vaccine is used for swine flu or pigs are vaccinated against influenza. Both include dead viral cells. However, no vaccine against swine flu does not give one hundred percent guarantee that the animal will not get sick or become a carrier. So, some well-known vaccines are already ineffective, because the virus is modified, mutates.
Today, to protect themselves from swine flu, bivalent vaccines (including two pathogens) are often used on farms, sometimes several at once.
The use of vaccines helps to avoid infection or serious complications, but it does not interfere with the spread of the virus. It is precisely because the pathogen mutates that the problem of effective protection against swine flu vaccine remains open, and farms continue to suffer losses.
If you read the article "Vaccinations of pigs from birth," you will learn how to fight other dangerous diseases with vaccines.
Preventive measures: how to protect livestock
We told you how to treat swine flu, but it is always better to prevent infection. On livestock farms the most important obstacle to the disease is the strict observance of all veterinary regulations and hygienic standards.
All rooms should be dry and warm enough, bedding should be changed regularly, cleanliness of feed should be monitored. All pigs entering the farm must first be in quarantine, undergo a veterinary examination. Those animals that have flu symptoms are urgently isolated from the rest.
In addition, the prevention of swine flu includes the disinfection of premises. Use quicklime (20%), sodium hydroxide (solution 2%), 4% hydrogen peroxide, the drug "Virkon-S", diluted in a ratio of 1: 100.
It is also important how you transport animals, especially piglets. In the rain, severe frost, with a cold wind this can not be done. In other cases, before the trip, the piglets are given sedatives, ascorbic and succinic acid as a tonic.
And do not forget that, although the vaccine does not protect 100% against the swine flu, it reduces the risk of disease many times over.
What people should know about the virus, methods of protection
The virus that infects humans is a mutant hybrid of ordinary influenza A and H1N1. It is called A (H1N1), and pigs can hurt them and spread it. At risk, in the first place, workers in the pig industry.
A sick person is contagious the day before the first symptoms and 5-10 days after that. Since the pathogen is very aggressive, the sick cannot be contacted by other people, especially in public places.
In general, the measures for protection against swine flu are the same as for other viral infections: you should often wash your hands, do not touch your face and mucous membranes with dirty hands, and follow all sanitary and hygiene rules when working with animals. In farms where there are sick pigs, it is necessary to limit the contact of people with them. To care for infected animals, isolated individual employees. In addition to them, no one should go to the quarantine zone.
The human vaccine against swine flu in modern medicine does not exist. The strain of this virus is part of the standard complex influenza vaccines. These are Influvac, Grippol, Grippol Plus, Fluarix, Inflexal V and others. As in the case of animals, they do not always prevent infection, but can save from the severe course of the disease and complications that can lead to dire consequences.
About another dangerous disease for people, read the article "The danger of classical swine fever for humans"
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