Fascioliasis cattle - a disease that can bring great material damage to the farm. In an infected cow, milk yield decreases, weight decreases, and reproductive function is impaired. To protect livestock, it is necessary to conduct anthelmintic treatment in a timely manner and carefully choose pastures.
History of the disease
In the 14th century, in France, cattle breeder Jean de Brie wrote a book on sheep breeding and the manufacture of products from their wool. In it, he mentioned a new disease that causes rotting of the liver. Jean believed that this is due to the sheep eating poisonous herbs. After decomposition of the liver, in his opinion, worms started in it.
In the sixteenth century, another book was published, written by Anthony Fitzgerbert, it was called The New Treatise or the Most Useful Textbook for Farmers. In it, the author described in detail trematodes that cause fascioliasis in cattle.
Later, talented doctors took up the study of the disease: Italian Gabuccini, French Herner, Dutchman Gemma, German Fromman. Their work shed light on the nature of cattle fascioliasis. Later, in 1881, 2 fundamental works, independent of each other, were written by the German Leuckart and the Englishman Thomas. They described in detail the biology of trematodes causing fascioliasis in cattle.
Pathogen
On the territory of our country there are 2 types of fasciol - common and giant. In different regions, they can occur both together and separately from each other. Liver flukes feed on blood, for this they have a sucker on their head end.
Pathogens belong to hermaphrodites, that is, they have both male and female genital organs. Fascioli reproduce by laying eggs. They have a smooth shell, at one end of which there is a lid.
The causative agents of fascioliasis of cattle are biohelminths, that is, for complete development they need two hosts - intermediate and final. The first of these is a variety of freshwater mollusks. The final owner of biohelminths can be more than 40 species of animals and humans.
The life cycle of the causative agent of cattle fascioliasis consists of 4 stages: embryogony, parthenogony, cystogony and maritogony. The first stage is the development of the embryo and its hatching from the trematode egg. The length of the period depends on the ambient temperature, the presence of light, the amount of oxygen. The sexually mature fasciola is capable of laying up to 3,500 eggs per day, which with feces will be removed from the body of the infected animal. If the ambient temperature is below 5 degrees, then they die. If higher, then soon begins the hatching period of miracidia - a larval form covered with cilia.
For the onset of the next stage - parthenogony - an introduction into the mollusk must occur. In it, miracidium drops cilia and penetrates the internal organs. About a week later, a new stage begins - cystogonia. A sporocyst is formed, and mobile redia having a worm-shaped form develop in it. Then the process goes into its last phase - maritogony. In the bodies of radium, cercariae begin to develop. Usually the development of the parasite takes from 2 to 5 months.
What is fascioliasis
This disease is a parasitic infestation. Breeding cattle diagnosed with fascioliasis is prohibited. This helminthiasis causes material damage to farms around the world. It affects the milk yield of cows, causes depletion of animals, contributes to the appearance of gynecological problems. Cattle with cattle fascioliasis become more susceptible to other infections.
Invasion can occur both in acute and in chronic form. Fasciola is most detrimental to the liver, as it is localized in its passages and ducts. The disease is common in all parts of the world where there is water, because it is in it that intermediate hosts - mollusks - live.
The incubation period of the disease
The period of asymptomatic development of the disease is often associated with the general health of the cow. If the immunity is strong, then the incubation period can take several months. This is dangerous because the owner can let cattle sick with fascioliasis enter the breeding.
Most often, the first symptoms of the disease begin to appear after a period of 1 week to 2 months. During this time, the pathogen moves to the hepatic ducts and begins to parasitize there. Most of all, the disease affects patients, weakened animals with poor immunity. After the incubation period, fascioliasis usually becomes acute. If you do not give the animal emergency veterinary care, then the disease can become chronic.
Causes
Usually, cattle are infected with fascioliasis when pastured on pastures infected with its pathogen. Cows can also catch helminthiasis through diseased cultivated plants, such as fodder beets with tops or oats. This occurs when vegetables or cereals are irrigated with fresh water from infected ponds. It is undesirable to give livestock drink unboiled liquid from dubious sources. Cows cannot be grazed in wetlands.
Another source of infection is sick animals. If the cows were not treated for helminths before going to pasture, then they are able to infect all surrounding livestock. Sometimes a cow with fascioliasis infects a whole herd. Also, wild animals with access to pasture are the source of helminthiasis. If the owner has a suspicion of fascioliasis in his cattle, then he is obliged to provide him with emergency veterinary care.
Symptoms
When ingested, pathogens try to get to the liver and begin to parasitize in it. There are 2 phases of the development of helminthiasis: acute and chronic. The first stage occurs after the pathogen penetrates inside and in the process of its passage to the hepatic ducts.
Symptoms of fascioliasis begin to occur in sick cattle: decreased appetite, which can subsequently go into a complete rejection of food, lethargy, and a decrease in milk productivity. A fever may begin, the temperature in the animal rises to 40 degrees and above. This causes shortness of breath, heart rhythm failure, tachycardia. The liver is enlarged, yellowness of the mucous membranes may appear. After a few weeks, the signs of acute fascioliasis begin to subside, it goes into the chronic stage.
This phase is characterized by the depletion of the animal, the deterioration of its coat. In a cow, a stop of the scar can constantly recur. Its mucous membranes have a yellowish tint. Pregnant cows may have abortions. Animals cough. Liver palpation is enlarged and painful. Bald spots may appear on the body. If fascioliasis is not treated at this stage, then it can lead to cirrhosis.
Diagnostics
If the owner has a suspicion of helminthic infestation in his livestock, then it's time to call a veterinarian. For the diagnosis of fascioliasis for laboratory tests, fresh manure is taken. To establish a diagnosis, feces are washed many times. If the animal is infected, then the eggs of the pathogen are found in it. This method does not belong to the most effective, the reliability of its results does not exceed 60%. Serological studies and the Shcherbovich method are also used.
The diagnosis can be made by a veterinarian according to symptoms. A major role in this is played by the season, the prevalence of the disease in a given area, the nature of the course. Sometimes animals undergo a diagnostic slaughter procedure.
Pathological changes
If the animal was subjected to a slaughter procedure, then specialists conduct a post-mortem examination. Usually sexually mature fasciol can be found in the ducts of the liver. They may also be present in intraperitoneal fluid. In the chronic course of the disease, salt is found in the bile ducts.
In slaughtered animals, fascioli itself may be present in the tissues. In the liver, tears, necrotic foci are found. Small hemorrhages are found in the intestines. Partial destruction of the liver, enlargement of the gallbladder is possible. Liquid is found in the abdominal cavity. If fascioliasis in a cow was started, then in a fallen animal, cirrhosis of the liver is diagnosed.
Treatment
Methods for controlling the disease may vary depending on the age of the pathogen. This is due to the fact that different substances can affect trematodes at different periods of their lives. Most often, veterinarians prescribe the following drugs against cattle fascioliasis: Dertil, Alben, Fazineks, Klozantel.
Most anti-trematode drugs are available in tablet form, but suspensions are also found. The drug "Closantel" is intended for subcutaneous injection. Most of the anti-helminth drugs give a restriction on the use of milk. The drug should be selected only by a veterinarian, self-medication can lead to the death of the animal.
Prevention
To prevent the spread of fascioliasis in animals, protective measures must be taken. A good effect is given by year-round non-walking content. Grass for cows is mowed on sowing meadows clean of fascioli or is not used at all in the diet. Cultivated plants show high productivity, they are more nutritious. If there is no possibility to sow meadows on your own, then you can mow grass on natural pastures, if they are not located near marshes. It is better not to harvest hay in such places. If the grass had to be mowed near marshes for the winter, then it should be aged for at least 6 months.
A good effect on reducing the incidence is given by pasture change. Since the fasciola life cycle takes from 70 to 100 days, you will have to do this every 2 months. Fresh manure is not allowed to be transported to the fields, this creates favorable conditions for the reproduction of the parasite. The feces are stored in one place, a heat reaction begins inside the heap and all pathogens die. After this, rotted manure can be taken out to the field.
In areas unfavorable for fascioliasis, it is imperative to conduct deworming in a timely manner. If the cows are expelled for grazing, then this event is carried out three times a year. To prevent the spread of fascioliasis, shellfish can be destroyed. This is done using treatments with copper sulfate or contribute to the reproduction of waterfowl.
Is fascioliasis dangerous for humans?
Infection of people with fascioliasis occurs infrequently, but sometimes it occurs. Symptoms in a sick person are similar to those observed in animals. People develop a fever, a headache begins, and their health worsens. Signs of allergies, skin itching, and hives may appear. Sometimes patients with Quincke's edema are recorded. Pain can be observed in the right hypochondrium and the epigastric region, vomiting, nausea, jaundice. The liver is increasing in size. Heart problems appear: tachycardia, myocarditis, pain behind the sternum. Without treatment, after a few weeks, the disease from an acute form becomes chronic.
In this phase, a person periodically has pains in the right side, the liver increases, jaundice can occur. If further medical assistance is not provided to the sick person, then the onset of cirrhosis of the liver, hepatitis, and severe anemia is possible.
Conclusion
Most often, fascioliasis is found in the southern regions, since they are more favorable for the development of its pathogens. In places that are dysfunctional due to the disease, it is necessary to carry out multiple preventive deworming. It is undesirable to graze cattle in lowlands or near swamps. The disease is dangerous for humans, so at the first suspicion of fascioliasis, you need to call a veterinarian.