RUMINAL TYMPANY

Abnormal distension of the rumen and reticulum due to excessive retention of fermentation gases.
Two forms:
- Primary Ruminal Tympany: Persistent foam mixed with rumen contents.
- Secondary Ruminal Tympany: Free gas separated from ingesta due to interference with eructation.

Gas bubbles in the rumen:
- Normally coalesce and separate from ingesta to form pockets of free gas.
- Ultimately eliminated by eructation.

Major problem for cattle on bloating forages (e.g., legumes) and feedlot cattle on high-grain diets.
Occurs shortly after grazing on bloating pastures, particularly when legumes are in the prebloom stage.
Mortality and morbidity rates are significant, leading to economic impact due to management costs.

Often occurs in individual animals due to physical obstruction affecting eructation.
Risk factors include reticular adhesions.

Production of foam that traps normal fermentation gases within the rumen.
Coalescence of gas bubbles is inhibited, raising intraruminal pressure.
Foaming qualities of soluble leaf proteins in leguminous plants and alfalfa hay contribute to the issue.
In feedlots, finely ground grain aids in producing frothy content.
Involves changes in ruminal microflora:
- Increase in encapsulated bacteria that produce slime, leading to stable foam.

Can result from esophageal obstruction, esophagitis, and ruminal acidosis among others.
Free gas may be released easily in feedlot situations.

In frothy bloat, gas bubbles fail to separate from rumen contents, impeding eructation and increasing volume of ruminoreticular contents.
Characteristic frothiness arises from inadequate gas bubble coalescence.
In free-gas bloat, gas can separate but cannot eructate due to esophageal or reticulorumen abnormalities.
Initial hypermotility occurs; ultimately leads to decreased motility and tone.

Sudden death or evident bloating shortly after exposure to bloat pastures, especially in beef cattle.
Initial signs may arise quickly, causing rumen distension, particularly in the left abdomen.
Discomfort characterized by frequent changes in stance, kicking at the abdomen, and rolling.
Symptoms of discomfort include increased respiratory rate, mouth breathing, and salivation; severe cases may exhibit projectile vomiting.
Later stages yield reduced ruminal contractions due to extreme distension, leading to limited gas release even with intervention.

Ruminal tympany is a primary consideration for cattle with abdominal distension.
Identify primary bloat through dietary conditions and froth presence via stomach tube.
Secondary bloat recognized through longer-term symptoms and potential esophageal obstruction.
Differentiate from vagus indigestion, tetanus, neoplasia, and postmortem diagnoses from other diseases.

Remove affected cattle from bloating pastures.
Severe cases may require emergency rumenotomy; less severe cases may utilize a stomach tube or trocar to relieve gas.
Use of antifoaming agents directly into the rumen can help reduce surface tension in gas bubbles, aiding eructation.

Implement grass-legume mixtures, delayed grazing until dew is gone, and pre-grazing hay feeding.
Strategic use of antifoaming agents and consider sustained-release options (e.g., monensin).
For feedlot bloat, utilize total mixed rations that include chopped roughage with grain.