Coenurosis most often affects sick and weakened animals. At first, the disease proceeds imperceptibly for a person, the symptoms appear a little later. The consequences of the epidemic of coenurosis in the flock are catastrophic. Mortality from this disease is very high, so it is important to apply preventive measures in time.
History of the disease
Coenurosis of sheep has been known to humanity for a long time. The disease affects livestock and is popularly called chickenpox. The disease is most often found in ungulates, but in the literature there is a description of coenurosis of sheep in humans. For the first time, a 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 more often detected in children than in adults.
Nowadays, the disease is found 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, sheep coenurosis is recorded in the Caucasus and Volga regions. Most often, epidemics arise in the countries of Central Asia, since 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 regimen for sheep coenurosis.
Pathogen
The disease is caused by a parasite from the Taeniidae family. The causative agents of sheep coenurosis are cestode larvae that look like water bubbles. Their size varies from the size of a pea to a chicken egg. The cestode walls have two layers, they are thin and almost transparent. On the inner shell, tapeworms can be seen that fit snugly together. The proboscis of their heads are equipped with chitin hooks.
The main carriers of pathogens are canids and other carnivores, which, together with feces, bring out cestode eggs. They fall on grass and soil, where sheep and goats swallow them. Once in the body, parasites along with the bloodstream begin to move. They are carried to all internal organs and tissues. Pathogens tend to enter the spinal cord or brain, as they die in other places. After 3 months, censuses will be formed here.
If a carnivore eats a brain or spinal cord that suffers from sheep coenurosis, tapeworms will stick to its intestines. Sections will grow from them soon, and in 2-3 months the parasite will reach full development. Cestodes are able to parasitize in carnivores for about 6 months, but sometimes they do this for a year.
The eggs of the parasites are insensitive to cold, so they can easily wait out the winter under snow in the pasture. However, they do not tolerate direct sunlight, therefore, under the influence of rays they die in 3-4 days.
Description of the disease
Coenurosis of sheep 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 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.
The incubation period of the disease
Infection of sheep most often occurs in the pasture. They eat grass that has been infected with causative agents of coenurosis, and become ill. The incubation period for the development of the disease is from 2 to 3 weeks. This time depends on the age of the animal, its immunity and the presence of chronic diseases. Adults almost never suffer from sheep coenurosis.
In babies, the disease begins to manifest faster than in young growth. Scooby brightens also become more susceptible to coenurosis. Sometimes weak animals die at the initial stage of the disease. If an individual died without any reason, then a post-mortem examination of the tissues is necessary to establish a diagnosis. The disease has several types of pathogens, so the exact answer will be known after determining the structure of sheep coenurosis.
Transmission ways
The main carriers of the disease are animals of the canine and other carnivores. They spread cestode eggs along with feces. The greatest danger is dogs living in flocks.
Sheep infection occurs through water or food contaminated with the causative agent of coenurosis. Also, animals can get sick after communicating with brothers, because helminth eggs can be kept on their wool or on mucous membranes. The final host, such as the wolf, cannot directly infect sheep. It can only secrete helminth eggs along with feces that other animals swallow.
Most often, infection occurs on pastures. Lambs and young sheep eat grass, which contains the causative agent of coenurosis. Sometimes cattle become infected through a straw bed or infected soil in a stable.
Symptoms
Within 2-3 weeks after infection, the disease proceeds in a latent form. The fastest symptoms of sheep coenurosis begin to appear in lambs. They become restless, afraid of the owner, grinding their teeth. Usually this condition persists for two to three days. After the babies have cramps. Some lambs die at this stage of the disease. If the animal has survived, then the symptoms disappear.
Once 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 struck the victim’s brain. On palpation of the head, thinning of the bones of the skull is felt, especially in the frontal lobe.
An animal can twist its head for several hours without stopping, or throw it back and back away. Also for this disease is characterized by paralysis of the legs, a staggering gait, a disorder of coordination of movements.
Diagnostics
There are several ways to detect a disease in livestock. One of the most accurate is the diagnosis of sheep coenurosis by ultrasound. With the help of the apparatus, it is possible to see the cestode and the places of their localization. Also, by the number of parasites, one can judge the degree of infection, these data will help to choose the optimal treatment method. 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 activity of helminths, as a rule, it is refined. From the nasal cavity of the animal often comes pus with impurities of mucus. With coenurosis, which takes place in a hidden stage, the lamb's eyes 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 given by the use of the allergic Rongin method. It lies in the fact that the extract from the pathogen is introduced into the skin of the upper eyelid. If it has become thicker, this gives reason to suspect coenurosis in the animal. In this case, it is advisable to take a cerebrospinal fluid for examination.
Pathological changes
When cattle die from coenurosis during a pathological study, changes in the brain are found. Hemorrhages are visible on its surface, the hemispheres are mottled with winding passages that formed parasites. The cerebral ventricles are swollen, it is noticeable that excess fluid has accumulated in them.
With further investigation, the specialist sees bubbles having a size of up to 2 mm. It becomes noticeable that the brain is in a state of decomposition. The bones of the skull are thinned, 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 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 carry out the removal of cysts, the doctor first makes a craniotomy. The operation continues until all places of accumulation of parasites are destroyed.
If surgery for some reason is not possible, the veterinarian will prescribe a regimen for the conservative treatment of sheep coenurosis. The most commonly prescribed drugs are Albendazole, Fenbendazole, Praziquantel and others. Due to the action of drugs, parasites die. Also in the scheme with preparations against helminths, anti-inflammatory and anti-allergic medicines can be used. In some cases, chemotherapy may be prescribed.
Prevention
Treatment of coenurosis in sheep often causes difficulties, therefore, it is advisable to prevent the disease. Care should be taken when choosing 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 in time for helminths. Such prevention does not hinder the sheep themselves.
In places of keeping animals it is necessary to observe cleanliness, not to use dubious litter or soil. If the cattle is sick, then you must immediately show it to a veterinarian. If the doctor recommends euthanasia, then you do not need to self-medicate, this sheep is hopeless. All killed individuals must be disposed of after having undergone the cremation procedure.
Danger to humans
Coenurosis in humans is rare, no more than 50 such cases are described. Most often the victims of the disease are farm workers, shepherds and owners of farms.
Symptoms appear in a person 3–7 days after infection, but with good immunity, the incubation period can stretch for 3-4 weeks. Usually it all starts with an attack of headache, which may be accompanied by nausea or vomiting. Unpleasant sensations can also occur in the neck and spinal column.
A person can become depressed, he quickly gets tired, he has no desire to do anything. Patients often experience excessive sweating. If you do not consult a doctor at this stage, then disorientation in space may occur. Later, a person begins to faint regularly. Epileptic seizures, convulsions, paralysis are possible.
Most often, the doctor prescribes surgical treatment for the patient to remove all foci of helminthiasis in the body. If surgery for some reason is not possible, then resorting to conservative therapy.