Spring pig arthritis health plan

　　In clinical practice during the Spring Festival, we often see pigs exhibiting symptoms such as swollen joints in the limbs, lameness, trembling, ataxia, difficulty standing, and sometimes hind limb paralysis, unable to stand up, etc., a type of lameness in pigs. Common causes of these diseases include swine erysipelas, Haemophilus parasuis, and swine streptococcosis.

　　I. Chronic Arthritis-type Swine Erysipelas

　　The pathogen of this disease is Erysipelothrix rhusiopathiae. Chronic arthritis-type swine erysipelas develops from acute or subacute types, and there are also primary cases.

　　1. Clinical symptoms. The main manifestations are inflammatory swelling of the limb joints (carpal and tarsal joints are more common than knee and hip joints), stiffness, and pain in the affected leg. Later, acute symptoms disappear, and joint deformation becomes the main symptom, resulting in lameness in one or two limbs or inability to stand up. Affected pigs have normal appetite but slow growth, weak physique, and emaciation. The course of the disease lasts for several weeks or months.

　　2. Prevention and control measures. Penicillin is the drug of choice, and can be administered intravenously at 20,000 units/kg body weight, while intramuscular injection of routine doses of penicillin is given twice daily until body temperature and appetite return to normal. Do not stop medication too early to prevent recurrence or transition to chronic disease. Daily, strengthen feeding management, keep pigsty equipment clean, and regularly disinfect with disinfectants. Simultaneously, vaccinate against swine erysipelas according to the immunization program, generally starting at 3 months of age. When swine erysipelas occurs, immediately isolate and treat the affected pigs, and deeply bury or destroy dead pigs. For pigs in the same group that have not yet fallen ill, use penicillin for drug prophylaxis. After the epidemic is extinguished and medication is stopped, carry out a thorough disinfection and inject the vaccine to consolidate the prevention and control effect. Cull chronic diseased pigs early to reduce economic losses and prevent the spread of bacteria.

　　II. Infectious Haemophilus parasuis Disease

　　The pathogen of this disease is Haemophilus parasuis. Affected pigs are mainly characterized by serous, fibrinous, and multiple serositis and arthritis, as well as high mortality. It is a conditionally pathogenic bacterium, and it can be isolated from the upper respiratory tract of approximately 85% of pigs in normal pig herds.

　　1. Clinical symptoms. In pig farms where this disease occurs for the first time, the onset is rapid, with the disease occurring within a few days of contact with the pathogen. High fever, lethargy, and screams (pain) during movement or standing up appear. Some pigs exhibit muscle tremors, paralysis, and convulsions due to meningitis. Affected pigs have swollen joints in the limbs, lameness, trembling, ataxia, cyanosis of visible mucous membranes, and lateral recumbency death. When bacteria invade through skin wounds or spread through the blood to the skin, it can cause local skin inflammation or necrosis. If the ear shell is affected, it can lead to ear shell necrosis.

　　Pigs that die from this disease have characteristic lesions mainly on one or more serosal surfaces, including the pleura, peritoneum, pericardium, meninges, and synovial membranes of joints. When arthritis occurs, the surrounding tissues of the joints are inflamed and edematous, the joint capsule is enlarged, the synovial fluid is increased and turbid, and contains yellowish-green fibrinous purulent exudate. Other macroscopic lesions include pulmonary, hepatic, splenic, and renal congestion and focal hemorrhage, and lymphadenopathy. Adhesion occurs between the peritoneum and abdominal organs, and the joint cavity has increased synovial fluid containing fibrinous flocculent material and accompanying damage to articular cartilage (roughened cartilage surface is visible).

　　2. Prevention and control measures. Most Haemophilus parasuis are sensitive to cephalosporins, tetracyclines, gentamicin, and potentiated sulfonamides, but resistant to erythromycin, aminoglycosides, spectinomycin, and clindamycin. Suksheng according to 3~5mg/kg body weight, daily 1 times, for 3 days is highly effective for this disease.

　　This disease is easily misdiagnosed, so prevention is crucial. Because Haemophilus parasuis is a conditionally pathogenic bacterium, improving feeding management can reduce the incidence of this disease. Reduce the movement of piglets, and advocate self-breeding and self-raising; commercial pig farms specializing in raising and transporting piglets should try to purchase piglets from the local area (because the serotype of this disease has obvious local characteristics); maintain clean and hygienic pig houses, good ventilation, protection from cold and heat, minimize the invasion of other respiratory pathogens, avoid mixing pigs of different production stages in one pen, and improve the disease resistance of pigs.

　　III. Swine Streptococcal Disease

　　Swine streptococcal disease is an infectious disease caused by streptococci. Acute cases are mainly characterized by hemorrhagic septicemia and meningitis, while chronic cases are mainly characterized by arthritis and purulent lymphadenitis; pigs of all ages are susceptible, but it is more common in growing pigs weighing 30-50 kg; it can occur throughout the year, but is more common in spring and autumn, often occurring as local epidemics.

　　1. Clinical symptoms. Divided into septicemic type, meningitis type, arthritis type, and purulent lymphadenitis type.

　　The arthritis type shows joint swelling, suppuration, and lameness. Post-mortem examination shows purulent arthritis, congestion and roughness of the synovial membrane of the joint capsule, turbid synovial fluid, and mixed with yellowish-white cheesy masses, and yellowish gelatinous edema in the subcutaneous tissue around the joint.

　　2. Prevention and control measures. Isolate sick pigs in time and treat sick and suspected pigs. There are many drugs sensitive to streptococci: ceftiofur, cephalexin, ampicillin, amoxicillin, etc. Suksheng, at 3-5mg/kg body weight, once daily for 3 days, is significantly effective for this disease.

　　IV. Arthritis Caused by Secondary Viral Diseases

　　After pigs are infected with viruses, their immunity decreases, especially during seasonal changes. This allows conditionally pathogenic bacteria to invade the animal's body, causing secondary bacterial infections (such as Haemophilus parasuis), inflammation, and joint swelling.

　　Preventive measures. Strengthen disinfection and isolate and treat suspected sick pigs. If the pathogen is identified, use high-immune serum for emergency vaccination and treatment. Simultaneously, use drugs for auxiliary treatment. Suksheng should be administered at a dose of 3-5mg/kg body weight, once daily for 3 consecutive days, as an auxiliary treatment. To prevent viral diseases, vaccination and immunization are necessary, along with good daily management of the pig farm. It is also recommended to implement a Suksheng three-shot or two-shot health plan for piglets to prevent disease.