Dark red urine has many pathogenic factors! Etiology: insufficient phosphorus supply in diet leads to hypophosphatemia, which makes erythrocyte membrane brittle and hemolytic. Free drinking of calves is not restricted, or sudden binge drinking due to lack of water, or excessive water diversion due to hot weather can also be caused. Symptoms: Red urine is the most prominent clinical feature. In the first 1-3 days, the urine gradually changed from light red to red, dark red to purple brown, and then gradually subsided. Serious illness, depression, loss of appetite and reduced milk production; Anemia, pale mucous membrane with yellow staining, thin blood and decreased coagulation; Normal or slightly higher body temperature, shortness of breath and rapid heartbeat; Dry stool and dark urine. Differential diagnosis: 1. Nephritis is caused by the pollution of Corynebacterium renal and Escherichia coli. There are blood clots and pus in urine, and there are protein, epithelial cells, red blood cells, white blood cells and a large number of pathogenic bacteria in urine. 2. Leptospirosis is caused by leptospirosis infection. Young cattle are more likely to get sick and have more serious symptoms than adult cattle. Pregnant cows will miscarry and secrete bloody milk. Pathogens can be found in blood and urine. 3. The body temperature of cattle suffering from zoonotic diseases is elevated (heat leakage), and the lymph nodes on the body surface are highly swollen. A worm with a ring and a comma shape can be seen in red blood cells. This disease mainly occurs in summer and autumn. 4. Toxic hemoglobinuria Common poisons include mignonette, onion, nitrite and cottonseed poisoning. These substances usually cause obvious poisoning symptoms, such as no change in body temperature, obvious symptoms of digestive tract, and often accompanied by symptoms of nervous system. Treatment: intravenous injection of 20% sodium dihydrogen phosphate solution 300 ~ 500 ml, twice a day, severe cases can be cured in 2 ~ 3 days. Stop feeding phosphorus-deficient feed and take orally bone meal120 ~180g, 2 ~ 3 times a day. Continuous feeding 1 week. Or take 80 ~ 100g sodium bicarbonate daily for 3 ~ 4 days. For severe dairy cows, at the same time of treatment with phosphorus preparation, 1 ~ 2 liters of blood of healthy dairy cows were infused, and then glucose solution and physiological saline were given as adjuvant treatment. Prevention: the nutritional standard of diet should be supplied according to the needs of dairy cows, and full-price feed should be given; Phosphate fertilizer should be added to the soil lacking phosphorus; Properly control the amount of cruciferous feed and feed it in coordination with other feeds; In winter, 50 grams of bone meal or 500 ~ 1000 grams of wheat bran should be properly supplemented every day; Pay attention to the content of crude fiber in calf feed during lactation, and don't feed too much concentrate to promote rumen development and reduce the occurrence of this disease. Then there is the estrus of cows. If you say that you still don't get estrus under the condition of strengthening nutrition, try an aphrodisiac injection.