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Created page with '* Like bloat, rumenal acidosis is associated with mismanagement of feeding and involves cessation or depression of [[Rumination - Anatomy & Physiology|rumenal movements…'
* Like [[Bloat|bloat]], rumenal acidosis is associated with mismanagement of feeding and involves cessation or depression of [[Rumination - Anatomy & Physiology|rumenal movements]] with development of a degree of tympany.
* More common in cattle and goats than in sheep due to differences in diet.
===Clinical===
* Animals display signs of abdominal discomfort, but usually recover if treated.
* Acute disease can result in death if acidosis is severe.
===Pathogenesis===
* Occurs following feeding of highly fermentable material, usually carbohydrate, in the form of concentrate or cereal
** e.g. in barley beef feeding systems.
* An overgrowth of Gram positive bacteria results, breaking carbohydrate down very quickly.
** Increased [[Volatile Fatty Acids - Anatomy & Physioogy|volatile fatty acid]] production decreases the [[The Rumen - Anatomy & Physiology|rumen]] pH to about 5.
*** [[The Rumen - Anatomy & Physiology|Rumen]] epithelium is damaged- ruminitis.
*** Osmotic effects of [[The Rumen - Anatomy & Physiology|rumen]] contents produce severe dehydration.
*** Death may ensue when the [[The Rumen - Anatomy & Physiology|rumen]] pH drops to 4.5 or below.
* Normal flora may invade the damaged wall of [[The Rumen - Anatomy & Physiology|rumen]] e.g. Fusiformis necrophorum.
** Results in areas with mushy necrotic papillae.
** Especially on pillars and ventral parts of [[The Rumen - Anatomy & Physiology|rumen]].
* Excess gas production may occur
** Concentrate does not contain soluble proteins, therefore foam does not develop.
** Only mild to moderate free gas bloat is likely- much of the rumenal distension which occurs with rumenal acidosis is due to fluid sequestration in the [[The Rumen - Anatomy & Physiology|rumen]].
===Pathology===
====Gross====
* Gross PM findings may be non-specific.
* Ruminal stasis/bloat leads to rumen distension
* [[The Rumen - Anatomy & Physiology|Rumen]] contents are porridge-like.
* Rumenitis may be present
** Normal flora invading wall of rumen may enter blood as thromboemboli and travel in the portal flow to [[Liver - Anatomy & Physiology|liver]]
** Focal abscesses are produced, which heal with sunken star-shaped scars.
* Overgrowth of Clostridia may cause endotoxic shock with widespread petechial haemorrhages.
====Histological====
* Microvesicles may be present in the epithelium of the [[The Rumen - Anatomy & Physiology|rumen]] papillae.
** Contain mainly [[Neutrophils - WikiBlood|neutrophils]]
* May be focal erosions/ulceration.
===Sequelae===
* Scarring- necrotised papillae are replaced by smooth epithelium closely adherent to sub mucosa.
* Has economic significance since many barley beef livers are condemned at meat inspection.
* More persistent organisms can invade [[The Rumen - Anatomy & Physiology|rumen]] wall producing chronic infection.
** These are often fungi, e.g. Mucor (see [[Forestomach Inflammation - Pathology#Mucormycosis|Mucormycosis]]).[[Category:Forestomach_-_Nutritional_Pathology]][[Category:Cattle]][[Category:Sheep]][[Category:Goat]]
* More common in cattle and goats than in sheep due to differences in diet.
===Clinical===
* Animals display signs of abdominal discomfort, but usually recover if treated.
* Acute disease can result in death if acidosis is severe.
===Pathogenesis===
* Occurs following feeding of highly fermentable material, usually carbohydrate, in the form of concentrate or cereal
** e.g. in barley beef feeding systems.
* An overgrowth of Gram positive bacteria results, breaking carbohydrate down very quickly.
** Increased [[Volatile Fatty Acids - Anatomy & Physioogy|volatile fatty acid]] production decreases the [[The Rumen - Anatomy & Physiology|rumen]] pH to about 5.
*** [[The Rumen - Anatomy & Physiology|Rumen]] epithelium is damaged- ruminitis.
*** Osmotic effects of [[The Rumen - Anatomy & Physiology|rumen]] contents produce severe dehydration.
*** Death may ensue when the [[The Rumen - Anatomy & Physiology|rumen]] pH drops to 4.5 or below.
* Normal flora may invade the damaged wall of [[The Rumen - Anatomy & Physiology|rumen]] e.g. Fusiformis necrophorum.
** Results in areas with mushy necrotic papillae.
** Especially on pillars and ventral parts of [[The Rumen - Anatomy & Physiology|rumen]].
* Excess gas production may occur
** Concentrate does not contain soluble proteins, therefore foam does not develop.
** Only mild to moderate free gas bloat is likely- much of the rumenal distension which occurs with rumenal acidosis is due to fluid sequestration in the [[The Rumen - Anatomy & Physiology|rumen]].
===Pathology===
====Gross====
* Gross PM findings may be non-specific.
* Ruminal stasis/bloat leads to rumen distension
* [[The Rumen - Anatomy & Physiology|Rumen]] contents are porridge-like.
* Rumenitis may be present
** Normal flora invading wall of rumen may enter blood as thromboemboli and travel in the portal flow to [[Liver - Anatomy & Physiology|liver]]
** Focal abscesses are produced, which heal with sunken star-shaped scars.
* Overgrowth of Clostridia may cause endotoxic shock with widespread petechial haemorrhages.
====Histological====
* Microvesicles may be present in the epithelium of the [[The Rumen - Anatomy & Physiology|rumen]] papillae.
** Contain mainly [[Neutrophils - WikiBlood|neutrophils]]
* May be focal erosions/ulceration.
===Sequelae===
* Scarring- necrotised papillae are replaced by smooth epithelium closely adherent to sub mucosa.
* Has economic significance since many barley beef livers are condemned at meat inspection.
* More persistent organisms can invade [[The Rumen - Anatomy & Physiology|rumen]] wall producing chronic infection.
** These are often fungi, e.g. Mucor (see [[Forestomach Inflammation - Pathology#Mucormycosis|Mucormycosis]]).[[Category:Forestomach_-_Nutritional_Pathology]][[Category:Cattle]][[Category:Sheep]][[Category:Goat]]