Ruminal Tympany Tympany (Bloat, Hoven) • Normally, microbial fermentation continually generate a prodigious volumes of gas in the rumen that is eliminated by eructation or belching,. • Anything that interferes with eructation will cause major problems for a ruminant called ruminal tympany or, simply, bloat. • The disorder is perhaps most commonly seen in cattle, but certainly is not uncommon in sheep and goats. • Tympany is characterised clinically by: Elevated extended hunger fossa. Progressive Dyspnea and discomfort. Finally death due to respiratory failure.
Bloat: Contributing Factors 1. Animal factors: It may be hereditary in some spp.
2. Dietary factors. Substances
in the plant material make rumen fluid thicker and more viscous Grains (barley, wheat, soybeans) Particle size Rate of change
3. Microbial
Bloat: Contributing Factors 3. Microbial Foaming agents (polysaccharides) contained in rumen bacteria Fluctuations in rumen environment (grain feeding) = ↑ cell rupture Substances released by bacteria make rumen fluid thicker and more viscous
Pathogenesis • Bloat is the overdistension of the
rumen and reticulum with gases derived from fermentation. • Two types of bloat are observed, corresponding correspondin g to different mechanisms which prevent normal eructation of gas:
.1Frothy bloat) )primary tympany • In which gases are trapped in a stable,
persistent foam which is not readily eructated. • As quantities of this foam build up, the rumen becomes progressively distended and bloat occurs. • Bloat on pasture is frequently associated with "interrupted feeding" - animals that are taken off pasture, then put back on, or turned out on pasture for the first time in the spring. •
Pathogenesis • This type of bloat occurs most commonly in two settings: • Pasture bloat : Occurs on pasture, those containing alfalfa or clover that are rapidly digested in the rumen, results in a high concentration of fine particles that trap gas bubbles. Additiona Additionally, lly, some of the soluble proteins from such plants may serve as foaming agents. • Feedlot bloat Animals feed high levels of grain, especially when it is finely ground results in rapid digestion and an abundance of small particles appear to trap gas in bubbles. Additiona Additionally, lly, some spp. of bacteria that are a re abundant in animals on high concentrate rations produce an insoluble slime that promotes formation of a stable foam
(Free gas bloat (secondary tympany .2 • Occurs when the animal is unable to eructate er uctate free gas in the rumen ??. Obstructive bloat: The conditions that partially obstruct the esophagus )foreign bodies, abscesses, tumors or interfere with rumenoreticular motility )i.e. reticular adhesions, Vagus indigestion clearly can be involved. Posture bloat: Another cause of free gas bloat that in which a ruminant cannot eructate when lying on its back , and if a cow falls into a ditch and is unable to right itself, she will bloat rapidly. Ruminants that are to undergo surgery in dorsal recumbancy should be starved for 12 to 24 hours prior to surgery, to avoid posture bloat during surgery.
Pathogenesis • Regardless of whether bloat is of the frothy or free gas type, distention of the rumen compresses thoracic and abdominal organs. • Blood flow in abdominal organs is compromised,, and pressure on the compromised diaphragm interferes with lung function. function . • The cause of death is usually hypoxia due to pulmonary failure.
Diagnosis • History: History: Bloat is an acute disease with a short course, commonly manifest as sudden death, death, in unoticed animals. • Clinical signs: Diagnosis of bloat is typically simple, and the clinical picture largely reflects how long the condition has existed. • Palpation and percussion findings.
:Clinical Signs Signs include • Abdominal distension onto the left side. As distention continues, the entire abdomen may become distended. • Reluctance to move and cessation of feeding • Signs of distress: distress: anxiety and vocalization • Respiratory distress: distress: rapid breathing, neck extended with protruding tongue. • Staggering and recumbancy: recumbancy: once a animal with bloat is recumbant, death occurs rapidly. • Although bloat is primarily an acute disorder, chronic, recurrent forms are recognized in calves.
Free gas Tympany
Frothy Tympany assoc. Vagus indigestion
Dwarf with Bloat
Tympany in goat
Frothy tympany in goat
Tympany in camel
Post-mortem findings • Obvious distension of the rumen is certainly observed in animals that die of bloat, but also occurs rapidly after death from almost any cause in ruminants, and is not a useful diagnostic lesion. • Animals that die from bloat is ch. by congestion and hemorrhages in the cranial thorax, neck and head, and compression of the lungs. • Pressure from the distended rumen leads to congestion and hemorrhage of the esophagus in the region of the neck, while the esophagus in the thorax is pale. pale. • Bloat line :Demarcation between congestion and pallor seen in the region of the thoracic inlet • Usually, the liver is also pale because of displaced blood and interruption of blood supply.
Postmortem bloat
Bloat line
Treatment and Control • Bloat is a life threatening t hreatening condition and must be relieved with haste باستعجال. • For animals in severe distress, rumen gas should be released immediately by emergency rumenotomy. • Insertion of a large bore rumen trochar through trochar through the left flank into rumen is sometimes advocated, it is often complicated with peritonitis. • In less severe cases, a large bore stomach tube should be passed down into the rumen. • Free gas will readily flow out the tube, although it may need to be repositioned repeatedly to effectively relieve the pressure. • .
Treatment and Control • In the case of frothy bloat, antifoaming medications can be delivered directly into the rumen through the tube; with close observation to insure that the treatment is effective and the animal begins to belch gas, otherwise a rumenotomy may be indicated • Antifoaming agents to relieve frothy bloat include: Vegetable oils )corn, peanut or mineral oil, which are administered in 100-300 ml volumes to cattle. Effective commercial antifoam as polaxalene )a surfactant or alcohol ethoxylate )a detergent.
Trocer and canula
Frothy tympany Frothy R. content
Trocerization of left flank in camel
Control • Control of bloat relies on management coupled with medications, • Also, some of the techniques advocated may be applicable to small herds, but are too labor intensive to use with large herds. • Many of the techniques used are based on reducing the rate of fermentation that occurs in the rumen. • Examples of control strategies include:
Control 1. 2. 3. 4. 5.
Maintain pastures that have grasses mixed with legumes such as alfalfa Feed animals hay before turning t urning out on bloat-inducing pastures In feedlots, feed roughage such as straw or grass hay in addition to concentrate For animals on high grain rations, the grain should be cracked or rolled rather than finely ground Apply antifoaming agents prophylactically, either by drenching individual individual animals, incorporating into feed, or spraying on small pastures
Bloat: Preventive Measures Measures • Ionophores: Antibiotics feed additive (e.g
monensin (Rumenson ®), lasalocid (Bovatec®), and laidlomycin (Cattlyst) • It alter the flow of cations across cell membranes leading to reduction in G +ve bacteria which cause the bloat and other digestive problems associated with high carbohydrate diets.
• Surfactants: mineral oil ↓ activity for microbial bloat • Nutritional management: management: longstemmed grass hay, probiotics
