Rumen Acidosis and Stasis in Cattle and Buffalo

Rumen acidosis is not an exotic disease; it is a direct result of how the herd is fed. When concentrate is raised too fast, or fibre is cut because berseem is expensive or rice straw is short, rumen pH falls below 5.5 and the fibre-digesting bacteria stop working. The result is lost rumination, bloat, diarrhoea with undigested grain, a drop in milk, and laminitis that appears weeks later. Early signs look like ordinary colic, so treatment is often delayed until the rumen has stopped completely.

How acidosis develops inside the rumen

The rumen is a precise fermentation system that works between pH 6.2 and 6.8. When a large load of starch and sugar arrives quickly, acid-producing bacteria switch to rapid fermentation and generate lactic acid, which lowers pH faster than ordinary volatile fatty acids. pH drops to 5.5 or below, fibre-digesting bacteria die, and toxins accumulate inside the rumen.

Common Egyptian triggers include the sudden switch from berseem to concentrate at the end of winter, raising maize or barley without a stepwise increase, grinding grain too finely, feeding concentrate before roughage, irregular feeding times and limited drinking water in hot weather. Fat, high-yielding cows are more susceptible, as is any animal eating mouldy feed.

Acute and subacute signs

In the acute form the animal stops eating completely, stands hunched or lies down, the left flank is distended, and the rumen sounds silent through a stethoscope. Rumination stops, chewing falls below 40 movements per bolus, grey diarrhoea with whole grain appears, followed by dehydration and a weak pulse. Without treatment the animal can die within one to three days from acidosis and dehydration.

Subacute acidosis is more common and far less obvious: a gradual fall in milk, intermittent feed refusal, mild bloating after meals, and soft manure with a sour smell. Two weeks later laminitis signs appear: lameness, heat in the foot and a separated white line on the hoof. The farmer blames the foot, while the problem began in the rumen.

Diagnosis and measuring rumen pH

Diagnosis starts with auscultation of the rumen and assessment of motility, then sampling rumen fluid by stomach tube or rumenocentesis, a step only a veterinarian should perform. pH is measured immediately with a meter, and a reading below 5.5 confirms the diagnosis. Manure can also be checked for undigested grain, and milk fat falls in subacute cases.

Differential diagnosis matters: simple bloat, rumen stasis from fever or mastitis, mycotoxin poisoning and oesophageal obstruction can all mimic acidosis. Sodium bicarbonate is therefore not given blindly before examination, because blind correction can hide the real cause and delay proper treatment.

Treatment and ration correction

Acute cases need fast veterinary intervention: transfer of rumen fluid from a healthy donor, intravenous fluids for dehydration, gut antibiotics when bacterial infection is suspected, and pain relief. Do not force feed; offer good straw or berseem once the animal stabilises. Sodium bicarbonate is used under veterinary supervision at a calculated dose, because excess causes alkalosis and interacts with intravenous fluids.

Prevention rests on gradual change: any increase in concentrate is spread over two to three weeks, with roughage offered first in the morning. Mix a uniform total mixed ration and add mineral and vitamin supplements from our livestock vitamins, and consider rumen yeast to improve stability. Constant clean water and shade in summer are essential; diagnostic supplies are listed under medical supplies and livestock and sheep.

• Raise concentrate over two weeks, never in a single day.
• Offer straw or berseem before concentrate in the morning.
• Avoid very fine grinding and mix the ration thoroughly.
• Provide clean drinking water at all times, especially in summer.
• Watch rumination daily and never ignore a sudden milk drop.
• Ask your veterinarian before giving bicarbonate or antibiotics.

Conclusion

Rumen acidosis starts in the ration and ends in the hoof and the milk pail. Gradual concentrate increases, adequate fibre, clean water and daily rumination checks protect the rumen and save losses that only appear months later.

This article is general guidance and is not a substitute for examining your animal by a licensed veterinarian. In emergencies, contact your vet immediately.