Small Ruminants Flashcards
(265 cards)
What plant can cause “grass staggers” in sheep which lead to rabbit hopping rear limb gait, superexcitability, mustagmus and intentional head tremors (among other neuro/ataxic signs)
Canary grasses like folium, cano don and paspalum - genus phalaris
What in sheep can cause similar neuro and ataxic signs you would see if they ingested canary grasses (phalaris)
Hypomagnesemia - en happen when sheep graze lush pasture
What primarily causes bloat / rumen acidosis
Rich diets like alfalfa or forage , grain overload, those overeating or got into new feedstuffs, or those not adapted to the diet
What causes free gas bloat
Grain
What causes frothy bloat
Legume forage (alfalfa) more common, grain possible
What is the pathogenesis of rumen acidosis
Highly digestible chrbohudates like grain ingested in large amount ferment rapidly which drops the rumen ph, allows bacteria (lactobacillus) to further acidify the rumen which causes communal bacteria to die, osmotic pressure draws fluid into the rumen leading to systemic dehydration and shock - bacterial translocation happens due to damage rumen epithelium
What are clinical signs of bloat / rumen acidosis and when do they occur
Usually 6-36 hours after ingestion - colic, anorexia, neuro signs, abdominal distention (left), respiratory distress , toxemia, dehydration, diarrhea, death
How do you treat bloat
Orgogastric tube to relieve pressure - can give surfactant/oil, omen trouarization if in severe respiratory distress
How do you treat acidosis
Correct fluid/base disturbances and dehydration , NSAIDs for pain, rumen transfaunation, antimicrobials, thiamine supplementation
What clinical signs would you expect to see specific to an acidosis
Toxemia, dehydration, diarrhea, death
Define rumen transfaunation
Transferring when fluid with microbes + nutrients from a heathy animal to an animal with impaired rumen digestion
Why would thiamine supplementation help treat acidosis
Decreased thiamine allows for increased anaerobic metabolism which con worsen lactic acidosis - supplement thiamine to prevent
What comorbidities can occur due to rumen acidosis
Secondary polioencephalomalacia, liver abscesses, laminitis
What is polioencephalomalacia and what is often the cause in small ruminants
Thiamine deficiency causing bilateral neurologic signs - usually secondary to rumen acidosis and grain overload I can be due to diets that are low roughage high concentrate
How does a lack of thiamine lead to neuro signs (polioencephalomalacia)
Thiamine is necessary for ATP in the brain - without it, sodium and water accumulate leading to cerebral edema and necrosis of cerebral gray matter neurons
How does rumen acidosis lead to a thiamine deficiency
Thiamine produced by healthy rumen flora - with acidosis, thiamine producing bacteria go down and misfire using bacteria go up leading to deficiency
What are three possible differentials for a thiamine deficiency
Rumen acidosis, plant derived thiaminases ingested in bracken fern plants, or coccidia drug treatment with amprolium
What are clinical signs of polioencephalomalacia (a thiamine deficiency)
Bilaterally symmetric signs, central blindness, absent menace, intact PLR and palpebrals, opisthotonos, rigidity, nystagmus, head pressing, depression, recumbency
What is your top differential for bilateral neuro disease in small ruminants
Polioencephalomalacia - thiamine deficiency
What can help diagnose polioencephalomalacia in small ruminants post Morten
Edema and brain tissue that fluoresces under UV light
How do you treat polioercephalomalacia
Diane given slow IV or IM, Dexmethasone for edema
Define opisthotonos
Spasm of muscles casing backward arching of neck, back, etc
How can you differentiate between polioencephalomalacia and listeriosis in a small ruminant showing neuro signs
Polioencephalomalacia causes bilateral neuro signs , listeriosis cause, unilateral signs
What mostly causes listeriosis and when are uw more likely to see this
Spoiled or wet feed, improperly fermented silage, spoiled hay bales - most likely to see in winter