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Therio - Bovine - EED & Abortion in Cattle 2

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drraythe's version from 2017-09-10 02:14

EPIZOOTIC BOVINE ABORTION + MYCOTIC AGENTS OF ABORTION

Question Answer
What is EPIZOOTIC BOVINE ABORTION aka & where is it usually an issue?“Foothill abortion”, Endemic in California & adjacent States btwn 500-7000 feet above sea level
What czs Epizootic Bovine Abortion? How is it Xmitted?Unknown infectious agent – tentatively Pajaroellobacter abortibovis, the vector is a tick: Ornithodoros coriaceus (Pajaroello Tick)
When does Epizootic Bovine Abortion cz abortion?Only heifers or adult cows brought into the area are susceptible to the Dz (Will only abort once, thereafter appear immune)
What are the CSs of Epizootic Bovine Abortion?No CSs in affected animals, just Late term abortion storms
How does the abortus appear in a case of Epizootic Bovine Abortion?Fresh fetus (not lysed, not mummified) w/:
Petechial hemorrhage in conjunctive, oral cavity & tongue
Generalized lymphadenopathy
Severe ascites
Enlarged liver & spleen
Small, grey inflammatory foci in heart & kidney
How can you try to treat/prevent Epizootic Bovine Abortion?Introduction of new breeding stock a yr before breeding to allow them to attain immunity. Also, New modified live vaccine in the testing stages
Where do most environmental agents of mycotic Infxn come from?From soil, hay & poor-quality silage
How would you describe the abortions czd by mycotic agents?Usually late-term, sporadic abortions
What are the CSs of mycotic abortion like in the cows (moms)Usually none
Most commonly mentioned mycotic agent of abortion?Aspergillus fumigatus & other spp
What is the pathology of the aborted fetus/placenta like for mycotic agents?Severe Placentitis, Necrosis of cotyledons + leathery thickening of intercotyledonary space. There might also be fetal skin lesions in 25% of cases
If there are fetal skin lesions from a mycotic abortion, how do they appear?Raised circumscribed plaques resembling ringworm, in Areas around eyes, head, shoulders, back & sides
What is the best way to prevent mycotic abortions?Improved ventilation in barns, Don’t’ feed moldy hay/silage (esp. preg animals)
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NON-INFECTIOUS CZS OF ABORTION

Question Answer
What usually czs “Crooked Calf Dz” & why?Poisonous plants bc they stop fetus from moving-- joints don’t develop properly & "lock up"
What are the 4 listed poisonous plants that can cz crooked calf dz/ Multiple Congenital Contractures?Poison Hemlock, Lupines, Nicotiana glauca (tree tobacco), Locoweeds
Does Poison Hemlock cz abortion?Yes
Do Lupines cz abortion?NO, cz "crooked calf dz" aka Multiple Congenital Contractures (MCC)
Multiple Congenital Contractures (MCC) is akaCrooked Calf Dz
Does Nicotiana glauca (tree tobacco) cz abortion?No, czs "crooked calf dz" aka Multiple Congenital Contractures (MCC)
Do Locoweeds cz abortion?YES
Which plant has the Toxic principle swainsonine?Locoweeds
Do Broomweeds cz abortion?YES (only green thing after winter-- cows often eat it then & then abort)
How do pine needles affect the pregnancy?CZ ABORTION in the LAST TRIMESTER. Dams also often get RFM & metritis following abortion
What kind of pine needles cz abortions?Ponderosa pines, Lodgepole pine & common juniper
Which plant has the toxin Isocuprussic acid, & what does this toxin do?The pine needle abortion agents (Juniper, Ponderosa pine, Lodgepole pine)
Czs constriction of blood flow to placenta
Why is fescue a problem?Toxicity czd by Ingestion of fungus-infected (Neotyphodium coenophialum) tall Fescue grass (Mostly Kentucky-31 cultivar)
What is Neotyphodium coenophialum, & what problems does it cz?If is the fungus which grows on tall fescue grass, & it produces Ergot alkaloids (esp ergovaline)
Which non-infectious agent can be exacerbated by hot weather?The ergot alkaloids produced by the fungus (Neotyphodium coenophialum) cz peripheral vasoconstriction, & high temps (>89F) make the problem worse
W/ what non-infectious agent do ergot alkaloids coincide? HOW do ergot alkaloids affect the cows?(Tall fescue grass)
(1) Cz peripheral vasoconstriction (worse if temp >89*) (Slobbering, open-mouthed breathing, reduced avg. daily gain; spend daylight hours in the shade/in water)
(2) Decreased reproductive efficiency (Decreased circulating prolactin, Acts like dopamine agonist, Decreased intensity of estrus, Increased EED, Altered CL Fxn, Reduced conception rates, Delayed puberty)
What are some CSs of summer slump/fescue foot?Slobbering, open-mouthed breathing
Reduced avg. daily gain
Spend daylight hours in the shade/in water
Decreased intensity of estrus
Increased EED, Altered CL Fxn
Reduced conception rates
Delayed puberty
Do ergot alkaloids/ fescue tox cz abortion?NO! Just dec repro efficiency
Sores on feet, heat exhausted, & repeat breeder cows might clue you in to what dz?Fescue tox/ ergot poisoning
How would you treat fescue tox?Tx not practical/economically feasible, however, would be slow-release formulations of Thiabendazole & Ivermectin to reduce some of the vasoconstricting effects, & Metoclopramide (to work as a Dopamine-receptor antagonist) (remember, dopamine dec prolactin & ergot alkaloids inc the action on the dopamine receptor, so we wanna antagonize that)
How can you help prevent fescue tox?Renovate Fescue pastures (Herbicide & re-plant)
Rotate cattle off Fescue during hot summer mos
Intercede Fescue pastures w/ legumes
Do not over fertilize – exacerbates effects of ergovaline
Supplement w/ corn (Allows efficient forage digestion & reduces toxic effects of Fescue)
What are some sources of pre-formed nitrates that cows would have access to?Fertilizer or nitrate-accumulating plants eg. Sudan grass, Oats, Wheat, Corn, Pigweed & Johnson Grass
Why do pre-formed nitrates cz abortion?Ruminants have nitrate-reducing bacteria in the rumen, which Allows conversion of NO3- to NO2- (nitrite). The NO2- oxidises the normal ferrous iron (Fe2+ ) in hemoglobin to the ferric state (Fe3+) forming methemoglobin Which Results in hypoxemic stress in tissues inclduding placenta = late-term abortion
Around what time in gestation do nitrates cz abortion?Late term abortion due to hypoxemic stress
If the fetus appeared to have died from hypoxemic stress, what agent might you suspect?Nitrates (converted to methemoglobin in rumen)
Which pharmaceutical should you exercise caution w/ around preg moms?Prostaglandins....duh
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