Pig farm veterinarians: interpreting the prevention and treatment of swine tapeworm disease
Maimo Veterinarian 2019.12.24
Taeniasis is a zoonotic disease, is a parasitic disease of tapeworm parasitism in the small intestine of the human body and causes a series of pathological changes, the public is familiar with the "pig cysticer tail cerstasis" is the larvae of the tapeworm, the larvae mainly parasitize the striated muscle parts of humans and animals, and its number can even invade the heart, brain, eyes and other important organs to cause serious harm. This paper summarizes the practical and efficient comprehensive prevention and treatment methods for the reference of the industry in combination with long-term veterinary clinical practice.
Keywords: Tapeworm pig middle host Clinical symptoms Diagnosis prevention and control measures
Pathogenic
The causative agent is tapeworm and its larvae (cysticercosis), an adult of which is a large tapeworm of the genus Bandaceae; mature larvae are oval-shaped, translucent cysts, filled with fluid in the cyst cavity, the wall of the capsule is a membrane, there is a small milky white nodule (head knot) on the wall, four round suction cups on the head knot, and two rows of hooks (about 25-50 small hooks) on the apical protrusion at the front. Generally speaking, the disease is conditional, because the incidence of infection of pig cysticercosis is through the history of circulating development inside and outside the body, pigs and wild boars are important intermediate hosts, canines, cats and camels may also be intermediate hosts, of which humans are also important intermediate hosts (terminal hosts); adults live in the small intestinal segment of humans, eggs or pregnancy nodes are excreted with feces after contaminating the breeding environment or dietary source, and are further developed into mature larvae with infectious force after being accidentally ingested by pigs; pig cysticercosis can survive in pigs for several years. After reaching a certain age, it will be calcified and die; humans will eat uncooked pork at high temperature, which if it contains infected viable porciniers, it will provide the oocyst with the nutritional environment needed for further development, which will develop into mature eggs after about 48 days, and form infectious eggs or pregnant sections excreted with feces after 50 days. It can be seen that the source control of the disease lies in the elimination of the source of infection "sick pigs" and "feces with insects (egg sacs, pregnancy joints)", including the feces excreted by people infected with pig cysticercosis, which should also be properly and harmlessly disposed of.
Popular features
There is no obvious seasonality in the incidence of this disease, but it is most high under the environmental conditions of high temperature and high humidity and pollution index exceeding the standard, so the spring and summer of long rain and sunshine are relatively high. The incidence of infection in the pig herd is related to the degree of environmental pollution of the pig house, the feeding management method, especially the health habits of the breeding management personnel and the health habits of the pig herd, the cleaning and disinfection disposal of the pig farm (house, barn) is not implemented in place is the direct cause of the high incidence of the disease, human and animal feces pollution of the breeding environment and diet source is the most important reason, pigs have pica, like to lick manure is the most susceptible to infection. The disease is mostly sporadic and regionally endemic, and its incidence and severity are directly proportional to the number of local taeniasis-affected animals (humans, cats, dogs and other intermediate hosts). Under natural conditions, pigs are highly sensitive and susceptible animals, cysticercles can survive in pigs for 3-5 years, wild boars, dogs, cats can also be infected, and humans are the only terminal host (can also be used as intermediate hosts).
Clinical symptoms
In the early stage of the disease, due to the movement of hooked larvae in the pig body, it has a mild to moderate pathogenic effect due to the movement of hooked worms in pigs, which has a mild to moderate pathogenic effect. Because the cysticercosis parasitism site is different and shows different symptoms, when parasitized in the brain, it can destroy the integrity of the brain, will cause epilepsy, convulsions, angle arch reversal, ataxia and other neurological symptoms, at this time the animal body's defense ability is significantly reduced, serious directly lead to death; when parasitizing the eye, it can cause visual impairment, shame or blindness; when parasitizing the respiratory system (lungs, trachea and bronchi) can cause dyspnea, swallowing difficulties, breathing rales, etc.; parasitize the leg muscle groups can cause movement disorders, Difficulty walking, inflexibility, lameness and paralysis. The overall visual examination can see that the growth and development of the diseased pigs are significantly inhibited, progressive wasting and anemia, and the late stage of the disease is severely malnourished, and abnormal changes in body shape will occur, such as "spindle shape, gourd type, lion head" and so on. Main view of dissection changes: most or local muscle group tissue contains cysticercosis, in the brain, liver, spleen, lungs, eyes and lymph, adipose tissue can also be found in the cysticer larvae live, early onset of cysticercosis outside the cell infiltration phenomenon, and then gradually fibrous changes, up to half a year later cysticer death and gradual calcification, so at this time the lesion tissue can be seen in the gray-white or gray-yellow hard nodules.
About diagnostics
There are no obvious pathological abnormalities in the early stage of the disease, so the diagnosis is more difficult, and only when there are more capsular cysticercosis on the superficial surface of the tongue, the slightly raised nodules can be seen, some need to be palpated to perceive, and some negative infections have no obvious symptoms. The disease can be differentially diagnosed by immunological examination methods such as carbon agglutination reaction, enzyme-linked immunosorbent assay, allergy reaction, cyclic precipitation test, and convective immunoelectrophoresis. In the health quarantine inspection of pork products, the focus is on the myocardium, tongue muscle, limb muscles and other tissues, and the disease can be diagnosed by finding that there are live clumps of clumps of cysticercosis or calcified tissue.
Preventive control
In view of the fact that the disease belongs to the zoonotic disease, so the control of the source of infection should be aimed at the two major categories of positive infection of people and animals, mainly to strengthen publicity and education work, health, official veterinary and food and drug safety supervision and other departments should work closely together, carry out extensive mass prevention and control actions, vigorously create a social atmosphere of group prevention and control, and do a good job in "tracking and inspection, symptomatic deworming, quarantine inspection, isolation and control, supervision and rectification" and other related control work. The main measures include: actively surveying patients infected with tapeworm in the area, effectively deworming treatment for patients, and strict harmless disposal of their excrement; strengthening the quarantine inspection of pigs entering and leaving the country and the quarantine of urban and rural pig slaughter (carcass quarantine), properly disposing of the positive individuals and unqualified pork products detected to prevent the formation of a circular chain of infection between humans and livestock; strengthening the daily management of the pig herd, trying to achieve the separation of livestock and manure, scientifically planning and laying out pig houses and adjusting the pig herd, so as to minimize the incidence of infection in the pig herd Pig farms (households) and free-range households of moderate scale in agricultural and pastoral areas should manage toilets, pig manure, and pig herds, strictly prevent pigs from licking human and animal manure, and should change the backward appearance of livestock-toilet applications, so that people have toilets, pigs have special pens (houses, fences), and do not use toilet rings; it is strictly forbidden to eat raw pork or uncooked pork, and develop good hygiene habits; early training of pigs to develop good habits of fixed-point excretion, fixed-point lying position, and fixed-point feeding; pig houses regularly carry out cleaning and disinfection work, and maintain cleaning, drying, and ventilation for a long time. A benign and livable environment with sufficient light.
treat
Currently commonly used allergens are praziquantel and propylthiazole. Praziquantel, according to 30-60mg / kg internal administration, 1 dose / day, even 3d; propietimidazole, according to 30mg / kg internal administration, 1 dose / day, even 3d, the interval between each dose is at least 24h, it is recommended that the morning pigs on an empty stomach when feeding the effect is better.
