Graduation thesis of animal husbandry

Diarrhea is a common disease in pigs with a high incidence rate, which can occur all year round, with an incidence rate of 50% ~ 60%.

1. Stop eating: Stop eating is the easiest way to treat pig diarrhea. Mainly used for a kind of diarrhea caused by poisoning, such as diarrhea caused by eating toxic moldy feed. First of all, stop eating, prevent toxic and moldy feed from entering the body, so that the poison can be quickly eliminated from the pig body, and avoid premature use of antidiarrheal drugs, resulting in closed-door detention. At the same time, we should choose the best antidote and treat it according to the cause. Common antidotes include pralidoxime, methylene blue, atropine and glucose.

2. Insect repellent method: This kind of diarrhea is mainly manifested as the symptoms of chronic diarrhea, such as emaciation, rough fur, listlessness, growth retardation, dysplasia, rough feces, and sometimes insects are discharged with feces. Microscopic examination of feces revealed a large number of eggs. When treating, we should choose the method of expelling worms, which will drive away diarrhea. Commonly used anthelmintics include trichlorfon, levamisole hydrochloride and alfredin.

3. Antibiotic therapy: This method is mainly used for a kind of diarrhea caused by pathogenic microorganisms. This kind of diarrhea has certain infectivity, the same clinical symptoms and the same pathological and anatomical characteristics. Pathogenic microorganisms can be detected by taking diseased materials for laboratory diagnosis. For diarrhea caused by Class I and II infectious diseases, comprehensive prevention and control measures such as isolation, blockade, disinfection and emergency vaccination should be taken while using antibacterial drugs, and satisfactory results have been achieved. Commonly used antibacterial drugs include sulfonamides, furans and antibacterial drugs.

4. Oral salt supplementation: No matter what causes diarrhea, pigs will lose a lot of nutrients such as water, salt and sugar, which will bring certain adverse consequences to pigs and even endanger their lives in serious cases. The death of piglets caused by dehydration is usually caused by the disorder of water and electrolyte, so rehydration is the key measure to reduce death. However, conventional intravenous infusion therapy is difficult to be used for the treatment of diarrhea because of its inconvenience. Oral rehydration salt is simple and economical, and has achieved remarkable effect in treating diarrhea of livestock and poultry. Oral rehydration salt is composed of sodium chloride, potassium chloride, sodium bicarbonate and glucose, which has the functions of supplementing water and electrolyte, regulating acidosis and supplementing nutrition. When in use, add 1 000 ~ 1 500 ml of water every 25 g, and you can drink or take it at will. The dosage is 50 ~ 80 ml for mild diarrhea, 80 ~ 100 ml for moderate dehydration, hypertonic dehydration 130 ml for total fluid volume.

(2) Diagnosis and treatment of piglet paratyphoid.

In the second half of 2003, a pig farmer in our city bought 2 16 piglets in three batches, and used 2 piglets for epidemic prevention 7 days after purchase. 165438+1In the middle of October,16, the newly purchased pig fell ill. By the beginning of 65438+February, 67 pigs became ill and 13 pigs died. Veterinarians treated with penicillin, streptomycin and sulfadiazine, and the effect was not satisfactory. After autopsy and bacteriological examination in our hospital, it was diagnosed as paratyphoid fever caused by salmonella. ?

1 clinical symptoms sick pigs are thin, with rough fur, pale skin and poor spirit, and like to fight hemorrhoids. His body temperature is 40 ~ 4 1℃, and there is purulent secretion in the corner of his eyes. Constipation occurred in the early stage of the disease, and there was a light green foul smell after diarrhea. After 1 week, purple spots appeared at the end of pig ears, neck and abdomen. ?

2 Pathological changes * * * Dissection of 2 dead pigs weighing about 25 kg showed blue-purple splenomegaly, mesenteric lymph node enlargement and gray-white medullary section; There are brown necrotic pseudomembranes of different sizes on the mucosa of the posterior segment of the large intestine, and ulcers can be seen when the pseudomembranes are torn open. Among them, 1 head liver showed scattered necrotic foci. No abnormalities were found in other organs. ?

Laboratory diagnosis (1) Smears of liver, mesenteric lymph nodes and heart blood of dead pigs were examined by Gram staining microscope, and small Gram-negative bacteria with blunt ends were found. (2) The dead pig liver was directly coated on ordinary agar and S.S. agar, and cultured at 37℃ for 24 hours, all of which grew in diameter. 2 mm？ Wet gray-white microcolonies. Small Gram-negative bacteria can be seen by examining typical colonies with a dyeing microscope. (3) The typical colonies were evenly coated on ordinary agar plates for drug sensitivity test. The results showed that the bacteria were highly sensitive to chloramphenicol, amikacin and ciprofloxacin. Susceptibility to sulfadiazine and oxytetracycline; Penicillin, ampicillin and streptomycin are hypoallergenic. (4) Random pairing? Eight heads? Blood samples of sick pigs were collected and antibodies against classical swine fever were detected by positive indirect hemagglutination test. Diagnostic solution was provided by provincial animal husbandry and veterinary station and produced by Lanzhou Veterinary Research Institute. All 8 serum antibodies are 3log? 2 and 4 logs? 2。 Combined with autopsy lesions, swine fever infection was excluded. ?

Preventive measures (1) Bury dead pigs, isolate sick pigs, and thoroughly disinfect pens.

(2) Inject amikacin into sick pigs, 65438 00 mg/kg? Weight intramuscular injection, twice a day, for 5 days.

(3) The whole group was mixed with norfloxacin, 65438 00 mg/kg body weight each time, 65438 0 days three times, and the soluble multivitamin 65438 0 weeks was added to the drinking water. According to the above method, all the piglets returned to normal except three pigs with severe symptoms died.

(3) Treatment of sow dystocia

Sows in dystocia should be rescued immediately. Midwives should cut their nails, wash their hands and arms with 0. 1% potassium permanganate solution or 2% lysol solution, disinfect them with alcohol, and then apply oil lubricant. The periphery of pig vulva can also be disinfected with Lysol solution or potassium permanganate solution with the above concentration. Midwifery instruments should also be boiled and disinfected. According to the different conditions of sow dystocia, symptomatic treatment is given.

For old and weak sows, pituitrin 10 ~ 30 units can be injected to promote uterine contraction and make piglets produce. If the fetus has not been delivered for about half an hour, the midwife can put her hand into the birth canal, massage the cervix, and slowly pull the fetus out with the contraction of the sow.

For dystocia caused by premature discharge of amniotic fluid, narrow and dry birth canal and large fetus, oil lubricant can be injected into the birth canal, and the midwife will put her hand into the birth canal and slowly pull the fetus out with the contraction of the sow.

For sows with dystocia caused by abnormal fetal position, the midwife can put her hand into the birth canal, push it into the hind limbs or forelimbs of the fetus and take out the fetus; If the sow's birth canal is dry, clean lubricant can be injected into it. If the fetal position cannot be corrected and caesarean section cannot or should not be performed, some parts of the fetus can be removed.

In the process of midwifery, we should try our best to prevent damage to the birth canal and infection. After midwifery, sows should be injected with antibacterial drugs to prevent infection. If the sow does not eat or has symptoms of dehydration, 500 ~1000 ml of 5% glucose saline and C0.5 g vitamin C should be injected into the ear vein to strengthen the postpartum care of the sow.

(d) Mixed infection of Toxoplasma gondii and swine pneumonia

From April to June, a disease characterized by persistent high fever and dyspnea occurred in a pig farm in Feixian County, Shandong Province. This disease is highly contagious and has a high mortality rate. In less than two months, 204 pigs became ill (accounting for 68% of the total number of pigs), 82 pigs died, and the mortality rate was 40%. After investigation and comprehensive diagnosis, it was finally diagnosed as a mixed infection of Toxoplasma gondii and porcine pneumonia. After treatment with antibiotics and sulfonamides, satisfactory results have been achieved. The diagnosis and treatment report is as follows. ?

The incidence of 1

There are 300 pigs in this farm, all of which are fattening pigs of 3 ~ 4 months old. At the beginning of April, the weather was rainy and rainy, and the pigs had symptoms such as cough, runny nose and fever. At that time, it was diagnosed as a cold, and the condition was controlled after treatment with antibiotics (mainly kanamycin). After April 1 1, You Zhu became ill. Kanamycin is still used after the onset, but the condition has not improved, but has become more and more serious. From April 1 1 to May 25th, there were 204 cases of * * *, and 82 cases died, with an morbidity rate of 68.5% and a mortality rate of 40%. It was diagnosed as mixed infection of Toxoplasma gondii and porcine pneumonia. After comprehensive treatment with antibiotics and sulfonamides in time, the disease was basically controlled in 2 days, and no pig died again. ?

2 Clinical symptoms

The temperature of sick pigs rises, generally at 40.5 ~ 42℃, showing heat leakage type. At the beginning of the disease, the mood is low, the appetite is poor, the gait is unstable, the conjunctiva is congested, and the urine is yellow. Except for a few pig diarrhea feces, most of them are dry feces with coal tar color. Some feces are attached with mucus, which shows cyanosis of mucosa, accelerated breathing, cough and rapid pulse. Some show obvious abdominal breathing; Some ears, neck and lower abdomen have erythema, and the finger pressure has subsided; Some people have bleeding spots on their skin. The sick pig was emaciated and the death time was 6 ~ 18 days. ?

3 Pathological autopsy

Four dead pigs and four seriously ill pigs were taken to autopsy. It was found that the sick pig was emaciated, the skin was blue, there were blood spots or bleeding spots under the skin, purple erythema on ears and limbs, and bleeding spots in various organs to varying degrees. Systemic lymph node swelling, congestion, hemorrhage, pulmonary hemorrhage, interstitial edema of different degrees. Some can see a small area of liver degeneration, a large number of foam-like mucus in the lungs and bronchi, and cellulose deposition in the pleura. Some pleural adhesions were accompanied by diseased lungs, pleural effusion and pericardial effusion, with a little more ascites; There are punctate hemorrhage and gray or yellow necrosis focus on the surface of liver, and there are bleeding spots in pericardium and epicardium; Bleeding and ulcer at the bottom of stomach; There is a bleeding point on the spleen. ?

4 laboratory diagnosis

(1) The pleural effusion, ascites, heart blood, lymph nodes, lungs, liver and spleen of sick pigs were smeared. After Gram-negative or Giemsa staining, microscopic examination showed Gram-negative, scattered oval, bipolar stained trophozoites and pseudomembranes.

(2) The mucus in the lungs and bronchi of sick pigs was taken aseptically, inoculated on sheep blood agar plate, and cultured at 37℃ for 24 h, and the bacteria grew well, forming light gray, round, smooth, moist and dewdrop-like colonies. There was no hemolysis around the colony. Pure cultures were taken from typical colonies and smeared. After staining and microscopic examination, scattered elliptic gram-negative bacilli were found. After pure culture at 37℃ for 24 h in several media, it was found that the strain did not grow on MacKangkai agar plate. Growing on serum agar plate, small colonies with light gray, dewdrop shape, smooth and shiny surface and neat edges were formed. When observed under 45-degree refraction, the colonies are blue-green, with golden light and narrow red and yellow bands at the edges. It is slightly turbid in broth medium, with thick sediment at the bottom of the tube and fungus ring on the surface.

(3) The pure culture of the isolated strain was used in various biochemical tests, and the results showed that the strain could decompose glucose, fructose, sucrose and xylose, producing acid but not gas; Non-fermented lactose, rhamnose, sorbose, inositol, primary gum; Can produce indigo matrix and h? 2S, M.R. and VP tests were all positive, and gelatin did not liquefy.

(4) The spleen and lymph nodes of sick pigs were ground into 1∶ 10 suspension containing PBS with pH 7.2, and then divided into two parts. 1 part does not add any antibiotics, 0.3ml；; Was injected intraperitoneally into each mouse. The second part was treated with penicillin and streptomycin (each 1 000 IU(μg)), and each mouse was intraperitoneally injected with 0.5 ml. All patients died within 72 hours. The blood, ascites and spleen of dying mice were smeared and stained under microscope, all of which were oval, bipolar staining bacilli and typical Toxoplasma gondii. Where are the second group of mice? 10~? 12 days. The ascites was smeared, stained and microscopically examined, and a large number of free Toxoplasma trophozoites were found.

(5) Blood was collected from the sick pig's anterior vena cava, and the serum was separated, and the fuel test was positive. ?

Combined with the incidence, clinical symptoms, pathological autopsy and laboratory examination, it was diagnosed as mixed infection of Toxoplasma gondii and porcine pneumonia. ?

5 preventive measures

(1) Carry out centralized isolation treatment on sick pigs, at the same time, improve feeding management, avoid crowding and cold, and eliminate factors that may reduce the disease resistance of the body. Sick and dead pigs are strictly handled and thoroughly disinfected.

(2) Penicillin (according to1.000 ~1.5000 iu/kg body weight) and streptomycin (according to 10 ~ 20 mg/kg body weight) can be used to enhance sulfanilamide 6 in sick pigs. Methoxypyrimidine injection (TMP 0.2 g and SMM 1.0 g are dissolved in 10 ml, which is 20 ~ 25mg/kg body weight based on the total amount of the two drugs) is injected into muscle 1 ~ 2 times a day, and oxytetracycline and SMM are mixed in the feed after 3 days.

(3) uninfected pigs can be mixed with oxytetracycline and SMM at a dosage of 500 mg/kg for 3-5 days. After taking the above control measures, the death of pigs stopped soon and the epidemic situation was controlled.