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Ruminal tympany, also known as bloat, is a disease of ruminant animals, characterized by an excessive volume of gas in the rumen. Ruminal tympany may be primary, known as frothy bloat, or secondary, known as free-gas bloat.[1]

In the rumen, food eaten by the ruminant is fermented by microbes. This fermentation process continually produces gas, the majority of which is expelled from the rumen by eructation (burping).[2] Ruminal tympany occurs when this gas becomes trapped in the rumen.

In frothy bloat (primary ruminal tympany), the gas produced by fermentation is trapped within the fermenting material in the rumen, causing a build up of foam which cannot be released by burping.[3] In cattle, the disease may be triggered after an animal eats a large amount of easily fermenting plants, such as legumes, alfalfa, red clover, or white clover.[1] Some legumes, such as sainfoin, birdsfoot trefoil and cicer milkvetch are not associated with causing bloat in cattle.[4] In feedlot cattle, a diet containing a high proportion of cereal grain can lead to primary ruminal tympany.[5] The main signs of bloat in cattle are distension of the left side of the abdomen, dyspnea (difficulty breathing) and severe distress. If gas continues to accumulate, the right side of the abdomen may also become distended, with death occurring in cattle within 3–4 hours after symptoms begin.[1]

In free-gas bloat (secondary ruminal tympany), gas builds up in the rumen and cannot escape, due to blockage of the esophagus.[1]


  1. Removal of gases through trocar or cannula
  2. Use stomach tube and remove the ruminal digesta
  3. Medi oral (antifoaming agent) 10ml+250ml warm water and drench to the animal. If antifoaming agent not available, vegetable oil can be used, 400–500ml per large animal
  4. Sodium bicarbonate
  5. Nux vomica
  6. Antihistamine is used to avoid lameness. One particular sign in acidosis is lameness. Because lactic acid accumulates in the coronary band, it causes irritation; histamine is released which causes lameness, so antihistamine is used to avoid it.[citation needed]

Cultural depictionsEdit

Thomas Hardy's novel Far from the Madding Crowd depicts a flock of sheep suffering from bloat, who are treated by Gabriel Oak with a trocar to release the gas.


  1. ^ a b c d Constable, PD; Hinchcliff, KW; Done, SH; Gruenberg, W (2016). "Chapter 8: Diseases of the alimentary tract - ruminants. Ruminal tympany (bloat)". Veterinary Medicine: A textbook of the diseases of cattle, horses, sheep, pigs and goats (11 ed.). Elsevier Health Sciences. pp. 473–482. ISBN 9780702070587.
  2. ^ Reese, William O (2013). "Chapter 12: Digestion and absorption". Functional anatomy and physiology of domestic animals (4th ed.). Wiley. pp. 359–420. ISBN 9781118685891.
  3. ^ Boden, Edward (2001). "Bloat". Black's veterinary dictionary (20th ed.). London: A & C Black. pp. 68–69. ISBN 9780713650624.
  4. ^ Majak, W; Hall, JW; McCaughey, WP (May 1995). "Pasture management strategies for reducing the risk of legume bloat in cattle". Journal of Animal Science. 73 (5): 1493–8. doi:10.2527/1995.7351493x. PMID 7665381. 
  5. ^ Cheng, KJ; McAllister, TA; Popp, JD; Hristov, AN; Mir, Z; Shin, HT (January 1998). "A review of bloat in feedlot cattle". Journal of Animal Science. 76 (1): 299–308. doi:10.2527/1998.761299x. PMID 9464911.