Rumen Impaction in Cattle

Rumen Impaction

• Rumen impaction is the accumulation of indigestible materials in the rumen, leading to distension of the rumen and passing of scanty or no feces.
• Indigestible foreign bodies (IFB) such as polythene bags, metallic objects, fibers, and hair balls can cause rumen impaction.
• IFB are more common in females than males, and 91.02% of cases occur in adult cattle.
• Clinical signs of rumen impaction include pale mucous membrane, absence of rumination, and reduced ruminal motility.
• Complete cessation of rumination, impacted rumen, atony, and reduced rumen motility are also observed.
• Rumen impaction can cause depression, anorexia, reduced milk yield, abdominal distension, and loss of defecation.
• Blood biochemical changes, such as highly significant decreases in hemoglobin, PCV, and total erythrocytic count, with leukocytosis and normocytic normochromic anemia, hypoproteinemia, and hypocalcemia, may be observed in some cases.

Impaction of the Abomasum

• Impaction of the abomasum develops in pregnant beef cows during cold winter months when cattle have decreased water intake and are fed poor-quality roughage.
• The cause of dietary abomasal impaction is due to consumption of excess roughage low in both digestible protein and energy.
• Impaction with sand can occur if cattle are fed hay or silage on sandy soils, or root crops that are sandy or dirty.
• Outbreaks may affect up to 15% of all pregnant cattle on individual farms when the ambient temperature drops to -2°C or lower for several days.
• The pathogenesis is related to diet, and the abomasum becomes impacted, leading to sub-acute obstruction of the upper GI tract.
• Ions of hydrogen and chloride are continually secreted into the abomasum, resulting in alkalosis with hypochloremia.
• Varying degrees of dehydration develop, and fluids are not moving beyond the abomasum into the duodenum for absorption.
• Sequestration of potassium ions in the abomasum results in hypokalemia.

Clinical Findings and Lesions

• Complete anorexia, scant feces, moderate distension of the abdomen, weight loss, and weakness are usually the initial signs of dietary abomasal impaction.
• Body temperature is usually normal but may be subnormal during cold weather.
• A mucoid nasal discharge tends to collect at the external nares and on the muzzle.
• The heart rate may be increased, and mild dehydration is common.
• The rumen is usually static and distended with dry contents, but it may contain excess fluid if the cow has been fed finely ground feed.
• The pH of the ruminal fluid is usually normal (6.5-7).
• Protozoal activity in the rumen ranges from normal to a marked reduction in numbers and activity.
• The impacted abomasum is usually in the right lower quadrant on the floor of the abdomen.
• Deep palpation and strong percussion of the right flank may indicate the presence of a large, firm mass (impacted abomasum).

Diagnosis and Treatment

• Clinical diagnosis of dietary abomasal impaction is based on the nutritional history, clinical evidence of impaction, and laboratory results.
• The challenge is to recognize the cases of dietary abomasal impaction that will respond to treatment and those that will not.
• Medical treatment usually requires a confirmed diagnosis via right-side laparotomy.
• In cows that are treated, the metabolic alkalosis, hypochloremia, hypokalemia, and dehydration should be corrected.
• Lubricants can be used in an attempt to move the impacted material.
• Balanced electrolyte solutions are infused IV continuously for up to 72 hours at a daily rate of 80-120 mL/kg.
• Mineral oil can be administered at 4 L/day for 3 days.
• Dioctyl sodium sulfosuccinate (DSS) can be injected once into the abomasum during standing right flank laparotomy at 60-100 mL of a 25% solution for a 450-kg animal.