Sheep coenurosis: description, symptoms, treatment and prevention

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Cenurosis most often affects sick and weakened animals. At first, the disease proceeds imperceptibly to a person, symptoms appear a little later. The consequences of the coenurosis epidemic in the flock are catastrophic. Mortality from this disease is very high, so it is important to take preventive measures in time.

History of the occurrence of the disease

Sheep coenurosis has been known to mankind for a long time. The disease affects livestock and is popularly called chickenpox. The disease is most common in ungulates, but in the literature there is a description of sheep coenurosis in humans. The first case of this disease in humans was recorded at the beginning of the 20th century. The causative agent of the disease was studied, it was a sheep's brain. Later, similar cases were diagnosed in France and in African countries. The disease was diagnosed more often in children than in adults.

Today, the disease occurs in India, Africa and other not very developed countries. Occasionally, epidemics occur in America, Canada, France. In the Russian Federation and the countries closest to it, coenurosis of sheep is recorded in the regions of the Caucasus and the Volga region. Most epidemics occur incountries of Central Asia, as cattle breeding is still very developed there. Sheep coenurosis is very common in Kazakhstan.

In 1986, the scientist Kosminkov and his assistants developed a vaccine against the disease. In 2001, Dr. Akbaev invented a conservative treatment for coenurosis in sheep.

Pathogen

The disease is caused by a parasite from the Taeniidae family. The causative agents of sheep coenurosis are cestode larvae, which outwardly resemble water bubbles. Their size varies from the size of a pea to a chicken egg. The walls of the cestode have two layers, they are thin and almost transparent. On the inner shell, you can see tapeworms that fit snugly together. The proboscises of their heads are equipped with chitin hooks.

The main carriers of pathogens are canines and other carnivores, which, together with feces, bring cestode eggs out. They fall on the grass and into the soil, where they are swallowed by sheep and goats. Once in the body, the parasites begin to move along with the bloodstream. They are distributed to all internal organs and tissues. Pathogens tend to get into the spinal cord or brain, as they die in other places. In 3 months, tsenuris will be formed here.

If a carnivore eats the brain or spinal cord of a coenurotic sheep, tapeworms will attach themselves to its intestines. Soon, segments will grow from them, and the parasite will reach full development in 2-3 months. Cestodes are able to parasitize carnivores for about 6 months, but sometimes they do this for a year.

Eggs of parasitesinsensitive to cold, so they can easily wait out the winter under the snow in the pasture. However, they do not tolerate direct sunlight, so under the influence of the rays they die after 3-4 days.

Description of disease

Sheep coenurosis most often affects young animals that have not reached one and a half years. The first victims of the disease are weak individuals who already have any chronic diseases. The main carriers of helminthiasis are dogs that live with flocks. Carnivorous wild animals also play a significant role in the spread of coenurosis. One affected individual is capable of throwing up to 10 million eggs daily with feces.

The action of the pathogen begins with its penetration into the body. Depending on the type of parasite, its habitat will also be determined. The causative agent that causes cerebral coenurosis lives in the spinal cord or brain. This type of disease is more common in sheep than in other animals or humans. The causative agent of serial coenurosis settles under the skin or in the muscles. This disease is dangerous for hares and rabbits. The causative agent of coenurosis Scriabin prefers to parasitize in the muscles of animals. This disease most often affects sheep.

Incubation period for disease development

Infection of sheep most often occurs in the pasture. They eat grass that has been infected with coenurosis pathogens and become ill. The incubation period for the development of the disease is 2 to 3 weeks. This time depends on the age of the animal, its immunity and the presence of chronic diseases. The adults are practicallynever suffer from coenurosis sheep.

In babies, the disease begins to manifest itself faster than in grown-up young animals. Pregnant ewes also become more susceptible to coenurosis. Sometimes weak animals die at the initial stage of the disease. If the individual died without any reason, then it is necessary to conduct a post-mortem examination of the tissues to establish the diagnosis. The disease has several types of pathogens, so the exact answer will be known after determining the structure of sheep coenurosis.

Transmission routes

The main carriers of the disease are canids and other carnivores. They shed cestode eggs in their faeces. The greatest danger is represented by dogs living with flocks.

Sheep are infected through water or food contaminated with coenurosis pathogen. Also, animals can get sick after communicating with their brethren, because helminth eggs can be found on their fur or on mucous membranes. The ultimate host, such as the wolf, cannot directly infect sheep. It can only excrete helminth eggs along with feces that other animals ingest.

Most often, infection occurs in pastures. Lambs and young sheep eat grass that contains the causative agent of coenurosis. Sometimes cattle become infected through straw bedding or infected barn soil.

Symptoms

Within 2-3 weeks after infection, the disease proceeds in a latent form. The symptoms of coenurosis of sheep begin to appear most quickly in lambs. They arebecome restless, afraid of the owner, grind their teeth. This condition usually persists for two to three days. After the babies have convulsions. Some lambs die at this stage in the development of the disease. If the animal survives, the symptoms disappear.

Again, the disease makes itself felt only after 2-6 months. The animal begins to behave frighteningly. The lamb can lower its head and rest against the corner of the barn or any other obstacle, in this position it stands for hours. This means that the pathogen hit the brain of the victim. On palpation of the head, thinning of the bones of the skull is felt, especially in the frontal lobe.

The animal can turn its head for several hours without stopping or throw it back and back away. Also, this disease is characterized by paralysis of the legs, a staggering gait, a disorder in coordination of movements.

Diagnosis

There are several ways to detect disease in livestock. One of the most accurate is the diagnosis of sheep coenurosis by ultrasound. With the help of the device, it is possible to see cestodes and their localization sites. Also, by the number of parasites, you can judge the degree of infection, these data will help you choose the best method of treatment. Unfortunately, not every doctor has an ultrasound machine, especially in remote settlements. In this case, the veterinarian uses other diagnostic methods.

The doctor can palpate the skull; in places of active helminth activity, it is usually thin. Pus with mucus impurities often flows from the nasal cavity of the animal. With coenurosis, whichpasses in a latent stage, the eyes of the lamb change. They can increase or decrease in size, become a different color. Hemorrhages appear in the whites of the eyes.

A good effect in identifying the disease is the use of the allergic Ronzhin method. It lies in the fact that the extract from the pathogen is injected into the skin of the upper eyelid. If it has become thicker, then this gives reason to suspect coenurosis in the animal. In this case, it is advisable to take cerebrospinal fluid for examination.

Patological changes

When cattle die from coenurosis, changes in the brain are found during post-mortem examination. On its surface, hemorrhages are visible, the hemispheres are dotted with winding passages that were formed by parasites. The cerebral ventricles are edematous, it is noticeable that excess fluid has accumulated in them.

On further examination, the specialist sees blisters that are up to 2 mm in size. It becomes noticeable that the brain is in the stage of decomposition. The bones of the skull are thin, they bend easily, sometimes holes form in them.

Treatment

Now there are several schemes for getting rid of the disease. The most effective veterinary specialists consider the surgical treatment of coenurosis in sheep. With this method, cysts that are filled with cestodes are excised. This method is effective for both livestock and humans. In order to remove the cysts, the doctor first performs a craniotomy. The operation continues until all places where parasites accumulate are destroyed.

If the surgicalintervention is impossible for some reason, then the veterinarian prescribes a scheme for the conservative treatment of coenurosis in sheep. The most commonly prescribed drugs are Albendazole, Fenbendazole, Praziquantel and others. Due to the action of drugs, the parasites die. Also, anti-inflammatory and anti-allergic drugs can be used in the scheme with drugs against helminths. In some cases, chemotherapy may be prescribed.

Prevention

Treatment of coenurosis in sheep is often difficult, so it is desirable to prevent the disease. Care should be taken in the choice of pastures. For the prevention of coenurosis in sheep, it is not advisable to walk them in places where contact with carnivorous predators is possible. Dogs kept with a flock should be treated for helminths in a timely manner. Such prevention will not hurt the sheep themselves.

In places where animals are kept, it is necessary to keep cleanliness, do not use dubious bedding or soil. If the cattle is sick, then you need to immediately show it to a veterinarian. If the doctor recommends euthanasia, then there is no need to self-medicate, this sheep is hopeless. All slaughtered individuals must be disposed of after going through the cremation procedure.

Danger to humans

Coenurosis in humans is rare, no more than 50 such cases have been described. Most often, farm workers, shepherds and owners of subsidiary farms become victims of the disease.

Symptoms appear in a person 3-7 days after infection, but with goodimmunity, the incubation period can stretch for 3-4 weeks. Usually it all starts with a headache attack, which may be accompanied by nausea or vomiting. Unpleasant sensations may also occur in the neck and spinal column.

A person can become depressed, he quickly gets tired, he loses the desire to do anything. Patients often experience excessive sweating. If at this stage you do not consult a doctor, then disorientation in space may occur. Later, the person begins to faint regularly. Epileptic seizures, convulsions, paralysis are possible.

Most often, the doctor prescribes surgical treatment to the patient to remove all foci of helminthiasis in the body. If the operation is impossible for some reason, then resorts to conservative therapy.