Ruminal tympany (Bloat)
It is the over-distension of the rumen with gases which may be either frothy or free gas. The disease is characterized by change in silhouette of the abdomen, elevation of the left flank region, respiratory distress and death.
Etiology: Primary ruminal tympany (Ffrothy bloat) occurs in animals when they eat excess quantity of leguminous feed. Leguminous feed has the quality of foaming due to the soluble leaf proteins present in the legumes. The stable foam traps the normal gases of fermentation in the rumen. The cause of grain bloat is uncertain. Finely ground grains promote frothiness of the rumen contents which change the number and proportion of the ruminal protozoa and bacteria. Some species of encapsulated bacteria, which increase in number may be responsible for production of slime resulting in a stable foam formation. Flow and composition of the saliva has a definite role in ruminal tympany. Some animals, which secrete less saliva, are more susceptible to bloat than non-susceptible ones. This increased susceptibility to bloat may be short term due to the change in the microflora of the rumen. Dispersed gas bubbles in the rumen inhibit eructation while in normal animal gas bubbles separate from the rumen contents to form pockets of free gas and are removed by eructation. Frothiness of the rumen contents, therefore, is caused by incomplete coalescence of the gas bubbles.
Secondary ruminal tympany (free gas bloat)
Physical obstruction to eructation caused by a foreign body lodged in the esophagus, stenosis or pressure from outside due to the enlargement of the lymphnode leads to development of free gas bloat. In secondary ruminal tympany, gas bubbles coalesce and separate from the ruminal contents, however the animal is not able to eructate because of certain abnormalities in the esophagus or reticulorumen.
Clinical signs: There may be sudden death in some animals. There is distension of the left paralumber fossa. Mouth breathing is observed which indicates dyspnoea. Animal may get up and lie down and may kick at the belly. There is protrusion of the tongue, extension of the head and salivation. Heart and respiratory rates are increased while the ruminal movements are decreased or absent.
Diagnosis: History of the case, particularly primary bloat, and response to treatment may lead to the diagnosis. Passage of a stomach tube will be of much help in revealing obstruction in esophagus.
Treatment: It depends on whether the bloat is primary or secondary. Animals should be removed from the source of pasture responsible for bloating. In severe cases, rumenotomy is indicated to relive the animal from dyspnoea. A stick may be put (tied) in the mouth so that there is continuous movement of tongue which is helpful in production of saliva and expulsion of the gases. Antifoaming agents are given to reduce the foam and rumen pH should be corrected. Synthetic non-ionic surfactants like dimethacone, silicone, poloxalene, etc. may be given once or twice daily depending on the severity of the case. In free gas bloat, passage of the stomach tube can relieve the patient but in frothy bloat the tube may be plugged. Antifoaming agents can also be administered through the tube. For the treatment of less severe cases, 150 to 200 g sodium bicarbonate dissolved in 1 liter water may be given orally to correct ruminal pH and reduce the gas formation.