Integrated Control of Toxoplasma gondii Complicated with Eperythrozoonosis in Swine

Since autumn, many pig farms in the suburbs of Luohe City, Henan Province have distributed an infectious disease with elevated body temperature, anorexia, blood stasis under the limbs, ear tips and abdomen, skin cyanosis, dyspnea, neurological symptoms in piglets, and reduced reproductive performance in sows. After epidemiological investigation, combined with clinical symptoms, pathological examination and laboratory tests, it was diagnosed as Toxoplasma gondii complicated with eperythrozoonosis. The relevant diagnosis and comprehensive prevention and control are introduced as follows.

1Prevalence and incidence

Since the middle of September, 320 pigs have developed the disease in more than 20 pig farms, with an incidence rate of 20% ~ 50%. The body temperature suddenly increased, showing a missed heat type. Blood stasis occurred in the ears, limbs and abdomen at the later stage of the disease, with a mortality rate of 40% ~ 50%. First, several sick pigs appeared one after another in a pen or several pens, and then gradually spread to the surrounding areas, spreading to the whole group, sometimes sporadically.

２clinical symptoms

Piglets and fattening pigs: pale skin, anemia and jaundice symptoms. Body temperature rises to 40-42℃, missed for 7 ~ 10d, the sick pig is depressed, can drink water, appetite is reduced to waste, accompanied by constipation or diarrhea, hind limb weakness, walking and swaying. As the disease progresses, the skin of the ears, nose, hind limbs and lower abdomen appears purplish red spots or hemorrhagic spots. Severe breathing difficulties, foaming at the mouth and suffocation. Most pigs over 5 months old can endure, but they often have symptoms such as cough, dyspnea, hindquarters paralysis, torticollis, and epileptiform spasms.

Pregnant sows and breeding boars: sick pigs with high fever 40~42℃, is a missed heat type, depressed, reduced food or appetite, like drinking water. Dung dry and with mucus, urine yellow. Nasal fluid flow, nasal lens dry, conjunctival flush. Dyspnea, mostly abdominal breathing or canine sitting breathing, accompanied by cough. Some sick pigs have hind limb paralysis and weakness, walking shaking, and ataxia. Severe cases in the ears, nose, abdomen and the inside of the limbs have bleeding or purple spots. After the onset of pregnancy sows, normal appetite, mainly for hind limb weakness, like lying, a few days later, hind limb paralysis, abortion or stillbirth.

3pathological changes

Pulmonary interstitial edema, with large amounts of yellowish clear fluid or jelly-like material coming out of the open lung. There is a large amount of mucinous foam in the trachea and bronchi. The spleen is enlarged, brownish red, scattered with hilly hemorrhagic spots. Thickening of pericardium, large volume of light yellow or blood red fluid in pericardium and thoracic cavity, clot in cardiac cavity. The liver is enlarged, and the surface has a needle tip to miliary hemorrhage or gray-white necrotic foci. The kidney becomes soft, with bleeding points or gray-white necrosis points, and the capsule is not easy to peel off. The bladder was slightly bleeding. Bleeding at the bottom of the stomach, with a superficial ulcer. There are bleeding spots in the large intestine. Systemic lymph node enlargement, congestion and bleeding or necrotic foci, section juicy, purplish red.

４Laboratory diagnosis

４．１isolation and culture of bacteria

The heart, liver, spleen, lung and lymph nodes of dead pigs were inoculated on common nutrient agar plate and blood nutrient agar plate respectively, 37C after 24h observation, no bacterial growth.

４．２direct smear method

Take high fever pigs (41~42℃) ear tip blood smear and lung hilar lymph node contact of dead pigs were stained by Giemsa and then examined by microscope. Typical toxoplasma trophozoite was found, with blunt round at one end and sharp at the other end. Cytoplasm was light blue, and nucleus was purplish red to blunt round at one end. At the same time, round, oval, pink or purple red on the surface or edge of red blood cells, with strong refractive index.

４．３intraperitoneal inoculation in mice

Take lung, liver, lymph nodes and other disease materials, grind them and add 10 times of normal saline (penicillin 1 per ml000IU and streptomycin 100mg), after 3０００Centrifuge for 10min at r/min, and inoculate the supernatant into the abdominal cavity of mice, 0.5-1.0mL for each mouse. Daily observation, 4 days after the mice appeared by coarse hair, respiratory symptoms, after death of peritoneal fluid and viscera for smear, with Giemsa staining after microscopic examination, visible a large number of toxoplasma trophozoites.

5Treatment measures

５．１Treatment of toxoplasmosis

① Insect resistance: the whole group is mixed with sulfanilamide -6-methoxine, the first dose is 50-100 mg/kg body weight, the maintenance dose is 25-50 mg/kg body weight, 1-2 times a day for 5 days. Severe pigs are injected intramuscularly with sulfanilamide -6-methoxine, 0.1 g/kg body weight, once a day for 5 days, and the dose is doubled for the first time. ② Cooling: intramuscular injection of aminopyrine, once a day for 5 days. ③ Control of secondary infection: intramuscular injection of cefazolin sodium, 20 mg/kg body weight, twice a day for 5 days. At the same time in the feed to add compound neomycin preparation. ④ symptomatic treatment: for patients with long course of disease and weak constitution, 200mL of 25% glucose solution and 5mL of vitamin C injection are supplemented once a day to enhance the disease resistance of pigs.

５．２Treatment of Eperythrozoonosis

Rice is injected intramuscularly at a weight of 11 mg/kg. Group sick pigs can be treated with 200g of arsanilic acid per ton of feed for 2 weeks. For pregnant sows, 180g of arsanilic acid was added per ton of feed for one week in a row, and then the adjusted dose was 90g of arsanilic acid per ton of feed for one month in a row. Iron can be injected intramuscularly into anemic pigs.

6comprehensive prevention and control measures

６．１Toxoplasmosis

① The pig farm carries out rodent control work, prohibits cats and dogs, and strictly prevents cat feces from contaminating the shed, forage, feed and drinking water. The discarded slaughtered materials must be cooked before they can be used as feed. Cats and dogs are the important carriers and excretes of the disease. The occurrence of the disease may have a great relationship with the free access of cats and dogs to pig farms. ② Establish and improve the management system of livestock houses. The pig house can be disinfected regularly with 1% lye, 3% fire lye, 5% plant ash or 1% ~ 3% lime water to ensure the cleanliness and hygiene of the pig house and sports ground and prevent the occurrence of the disease. ③Strengthening quarantine of pigs, timely detection and elimination of pigs with insects, purification of pigs, which is the fundamental way to reduce the incidence of the disease. The incidence of pig farms should strengthen the observation of pigs, pay attention to the pig's appetite, feces and body temperature changes, such as the discovery of abnormalities should be immediately isolated, timely treatment.

６．２Eperythrozoonosis

① Strengthen feeding management, do a good job in enclosure feeding hygiene, eliminate stress factors, expel ectoparasites, and pay attention to the cleaning and disinfection of medical equipment. ② 200g of arsanilic acid was added to each ton of feed for pigs. Sows are added 90g of arsanilic acid per ton of feed from the 21st to the 105 day of pregnancy to ensure safety.

7Conclusion

(1) Toxoplasmosis and eperythrozoonosis are infectious diseases that have only begun to spread in this city in recent years, and the simultaneous occurrence of the two diseases is an important reason for the difficulty of clinical treatment and repeated treatment.

(2) At present, the prevalence of eperythrozoonosis in pig farms is the main reason for the lack of purification of sows, and the low immunity caused by congenital eperythrozoonosis of piglets creates conditions for the occurrence and spread of various diseases.

(3) Taking effective measures to prevent the occurrence of eperythrozoonosis and eliminating pigs with subclinical eperythrozoonosis is the key measure to improve the resistance of pigs and prevent the occurrence of various diseases.