Common Diseases Causing Persistent High Fever in Pigs and Their Prevention and Treatment Methods

(1) Swine fever: The pig's body temperature rises to 40-42°C and does not subside persistently; appetite decreases or the pig stops eating, mental depression, shivering, lying prone and sleepy, huddling together or burrowing into straw; when standing and walking, the back is arched and the waist bent, limbs are weak, movement is slow, gait is unsteady and swaying, conjunctiva is red with purulent discharge, first constipation, then diarrhea; at the base of the ears, abdomen, inner sides of the limbs and other areas there are purplish-red bleeding spots that do not fade under finger pressure. Lesions: systemic lymph nodes are enlarged with peripheral hemorrhage, showing a red-and-white mottled marble-like appearance; the kidneys become pale with pinhead-sized bleeding spots on the surface; the spleen is enlarged and hemorrhagic, with hemorrhagic infarcts protruding from the surface at the edges; in chronic cases, button-like ulcers appear on the mucosa of the ileocecal junction of the large intestine.

Prevention and treatment: (1) Strengthen routine management and improve environmental hygiene. (2) Carry out regular preventive vaccination; to eliminate interference from maternal antibodies, the vaccine dose can be increased (2-4 doses per pig). In swine fever epidemic areas or threatened areas, a large dose (8-10 doses per pig) of swine fever vaccine should be used for timely vaccination. Increasing the vaccine dose is the best way to eliminate maternal antibodies and is also an effective measure for preventing and treating atypical swine fever. (3) When swine fever occurs in a herd, sick pigs should be promptly isolated and disinfected along with the pigs; in the early stage of the disease, anti-swine fever serum can be used for treatment, generally injected once daily for 2-3 consecutive times.

(2) Swine influenza: The incubation period is 2-7 days. The pig's body temperature suddenly rises to 40-41.5°C, reaching as high as 42°C, with reduced eating or complete refusal to eat, mental depression, muscle and joint pain, often lying on the ground unable to rise, rapid breathing, paroxysmal spasmodic coughing, dry and hard feces, and mucous discharge from the eyes and nose.

Prevention and treatment: (1) When the pig has a fever, use antipyretic and analgesic drugs: intramuscular injection of 30% analgin 3-5 milliliters, or oral aspirin 2-4 grams. (2) To control secondary infection, intramuscular injection of 2% aminopyrine 10 milliliters, or penicillin 50,000 units per kilogram of body weight.

(3) Swine pasteurellosis: Body temperature can rise to 41-42°C, with difficulty breathing, mouth open and gasping, sitting in a dog-sitting posture, coughing, congestion of visible mucous membranes, inflammation of the conjunctiva with purulent eye discharge. Red spots appear on the skin behind the ears, on the neck, abdomen, and inner sides of the limbs. The mortality rate is about 70%.

Prevention: Inject swine pasteurellosis vaccine regularly and on schedule, strengthen feeding management, and improve the pig's disease resistance.

Antibiotics with relatively good therapeutic effects include gentamicin, followed by penicillin and ampicillin.

(4) Swine streptococcosis: Suckling pigs are most severely affected, mostly showing the septicemic form. The body temperature of sick pigs rises to 41-43°C, conjunctiva is congested and red, with tearing, coughing, difficulty breathing, and purplish-red patches on the body surface. Movement is uncoordinated, and the hindquarters are inflexible. Sick pigs with arthritis show swollen and painful joints and lameness; sick pigs with purulent lymphadenitis show swelling of the lymph nodes under the jaw, in the neck, and in front of the thigh.

Prevention: Keep the pig pen clean and dry, and disinfect regularly. Penicillin has a relatively good effect in treating this disease, at 50,000-80,000 units per kilogram of body weight, twice daily for 3 consecutive days.

(5) Swine toxoplasmosis: Similar to swine fever and influenza. The pig's body temperature rises to 40-42°C. Sick pigs are mentally depressed, with reduced appetite, and in severe cases appetite is completely lost. There are petechial spots on the head, ears, and lower parts of the limbs. The hind limbs are weak and powerless, walking is unsteady, the pig prefers to lie down, and there is coughing. In severe cases, a dog-sitting posture appears. White foam flows from the mouth. Pregnant sows may abort.

Prevention and treatment: For sick pigs with relatively severe symptoms, use sulfa-6-methoxypyrimidine and sulfadiazine, each at 0.07 grams per kilogram of body weight, mixed with 100-150 milliliters of 10% glucose, and injected intravenously, generally 2-3 times. For pigs with milder symptoms, sulfa-6-methoxypyrimidine at 0.07 grams per kilogram of body weight is injected intramuscularly once, with the first dose doubled, twice daily, and recovery can be achieved after 3-5 consecutive days.

(6) Infectious pleuropneumonia: The body temperature of sick pigs can reach 42°C or higher, with extreme difficulty breathing, in a dog-sitting or lying-on-the-side posture, abdominal breathing, coughing, bloody red foam flowing from the mouth and nose, and cyanosis of the abdomen and ear tips.

Prevention and treatment: This disease is highly sensitive to penicillin, ampicillin, long-acting oxytetracycline, and others, among which long-acting oxytetracycline is the most sensitive.

(7) Pseudorabies: The body temperature of sick pigs rises to 41-42°C, with typical neurological symptoms, difficulty breathing, and occasional vomiting and diarrhea; peritoneal congestion with occasional small bleeding spots; enlarged kidneys with scattered bleeding spots and cyanosis of the ear tips.

Prevention: There is no specific drug for this disease; focus on strengthening routine management and ensuring proper vaccination.