Pig farmers, remember: if a pig has bloody diarrhea and stops eating, never blindly give injections or drench it with medication! On many pig farms, bloody diarrhea keeps recurring, pigs get thinner the more they are treated, and there are sporadic deaths—not because the medication is ineffective, but because the condition has not been identified correctly, the medication does not target it, or the course of treatment has not been completed. Today, we’ll explain it all at once: how to accurately distinguish the 3 types of bloody stool caused by swine dysentery, ileitis, and gastric ulcers, plus practical plans to address them at the root—beginners can use them directly too!
Swine dysentery is caused by Brachyspira hyodysenteriae and occurs most frequently in growing and fattening pigs. It can occur throughout the year.
Typical signs: passing mucoid, bloody feces mixed with fresh blood and pale pink-white fragments of intestinal mucosa; a strong, foul odor in the pen. In acute cases, body temperature is 40～41℃ and death occurs rapidly. In chronic cases, body temperature is usually normal, with recurrent bloody diarrhea, progressive weight loss, and stunted growth; cases are usually sporadic. Postmortem findings are concentrated in the large intestine, which is dark red and filled with mucus and blood. No characteristic lesions are found in other organs.
First, quickly distinguish 3 types of bloody stool
Swine dysentery: bleeding in the large intestine, with fresh, mucoid, bloody stool containing fragments of intestinal mucosa and a pronounced foul odor
Ileitis: bleeding in the ileum (small intestine), with clay-like gray feces or blackish-red, tarry loose stools
Gastric ulcers: black, tarry feces, generally without diarrhea, often accompanied by vomiting, with no mucus or mucosal fragments; often triggered by feed ground too finely, stress, or excessive stomach acid
II. Treatment Plan Implementation
Injection (prioritize severely ill pigs that are not eating or have bloody stools)
Lincomycin + acetylmequindox, 3–4 days.
Use with caution in pregnant sows, piglets, and weak pigs. Do not use in combination with olaquindox. Lincomycin must not be mixed in the same syringe with florfenicol or macrolides, as this can cause antagonism.
Large-group feed mixing
Tiamulin + colistin, used consecutively for 7–10 days, provides a consistent effect in controlling ileitis; for severe bloody diarrhea, combine with dimetridazole to reduce the likelihood of recurrence.
Three. Key points for caring for sick pigs
For pigs that have stopped eating, prioritize injections; do not rely solely on administering medication mixed into feed
Add multivitamins + glucose + electrolytes to drinking water to prevent dehydration and exhaustion
For bloody stools and refusal to eat feed, fluids may be administered intraperitoneally (glucose + normal saline + multivitamins)
Lower the crude protein content of the diet and feed small amounts of easily digestible liquid food.
Promptly isolate sick pigs, treat manure through fermentation, disinfect pens regularly, and reduce stress.
IV. Why does bloody diarrhea keep recurring?
Porcine spirochetes can survive for a long time in moist manure, and recovered pigs may also shed the pathogen intermittently. Many farmers stop medication as soon as the feces look normal, before the pathogen has been completely eliminated.
Group transfers, high stocking density, temperature fluctuations, feed mold, and frequent feed changes are all major predisposing factors.
For sick pigs whose illness has lasted more than 7 days, that have persistently refused feed, and are extremely emaciated, consider culling them promptly after assessment to reduce ongoing sources of infection on the farm.
Five. Health care plan for high-risk periods (seasonal changes, group transfers, and pig groups with a history of illness)
Tiamulin + dimetridazole + multivitamin complex, mixed into feed and used continuously for 7 days; at the same time, suppresses spirochetes and Lawsonia. Antibiotics should only be used for limited periods; long-term inclusion is prohibited to avoid developing antimicrobial resistance.
Drinking water formula during stress: multivitamins + glucose + vitamin K3, K3 can enhance intestinal hemostasis and reduce the risk of death from severe bleeding.
Supporting management: Do not grind feed too finely; strictly control mycotoxins; implement rodent control; maintain all-in/all-out management; thoroughly disinfect and dry empty housing.
Six. Important reminders
Be sure to complete the full course of medication; do not stop taking it early.
If the sick pig continues to pass blood in its stool, refuses feed, becomes lethargic, or dies, contact a veterinarian promptly for an on-site diagnosis.
African swine fever and classical swine fever can also cause bloody stools. First rule out serious infectious diseases, then administer medication according to the symptoms!
In closing
Bright red mucus and bloody stools indicate bloody diarrhea, black loose stools indicate ileitis, and black dry stools indicate gastric ulcers. Use targeted injections plus a full course of medicated feed, and it will basically be cured in one treatment without recurring.
Swine bloody diarrhea is not a serious disease, but misdiagnosis, indiscriminate medication, or an insufficient course of treatment will inevitably cause it to develop into a stubborn chronic disease, resulting in many stunted pigs and undermining the pig farm’s growth.
This solution is the simplest and most reliable permanent fix, proven in real-world pig farm operations. Pig farmers are advised to save it for future reference and use it as a guide when their pigs pass blood, to avoid detours and unnecessary expenses!