Therio- Bovine- EED & Abortion in cattle 2

wilsbach's version from 2015-11-04 18:38


Question Answer
what is EPIZOOTIC BOVINE ABORTION aka and where is it usually an issue?“Foothill abortion”, Endemic in California & adjacent States between 500-7000 feet above sea level
what causes epizootic bovine abortion? how is it transmitted?Unknown infectious agent – tentatively Pajaroellobacter abortibovis, the vector is a tick: Ornithodoros coriaceus (Pajaroello Tick)
when does epizootic bovine abotion cause abortion?Only heifers or adult cows brought into the area are susceptible to the disease (Will only abort once, thereafter appear immune)
what are the clinical signs of epizootic bovine abortion?No clinical signs 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) with Petechial hemorrhage in conjunctive, oral cavity & tongue, Generalized lymphadenopathy, Severe ascites, Enlarged liver & spleen, and Small, grey inflammatory foci in heart & kidney
how can you try to treat/prevent Epizootic Bovine Abortion?Introduction of new breeding stock a year before breeding to allow them to attain immunity. Also, New modified live vaccine in the testing stages
where do Most environmental agents of mycotic infection come from? from soil, hay & poor-quality silage
how would you describe the abortions caused by mycotic agents?Usually late-term, sporadic abortions
what are the clinical signs 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)


Question Answer
what usually causes “Crooked Calf Disease” and why?poisonous plants because they stop fetus from moving-- joints dont develop properly and "lock up"
what are the 4 listed poisonous plants which can cause crooked calf dz/ multiple congenital contractures? Poison Hemlock, Lupines, Nicotiana glauca (tree tobacco), Locoweeds
does Poison Hemlock cause abortion?yes
do Lupines cause abortion?NO, cause "crooked calf dz" aka Multiple congenital contractures (MCC)
Multiple congenital contractures (MCC) is akacrooked calf dz
does Nicotiana glauca (tree tobacco) cause abortion?no, causes "crooked calf dz" aka Multiple congenital contractures (MCC)
do Locoweeds cause abortion?YES
which plant has the Toxic principle swainsonine?locoweeds
do Broomweeds cause abortion?YES (only green thing after winter-- cows often eat it then and then abort)
how do pine needles affect the pregnancy?CAUSE ABORTION in the LAST TRIMESTER. Dams also Often get RFM & metritis following abortion
what kind of pine needles cause abortions?Ponderosa pines, lodgepole pine & common juniper
which plant has the Toxic principle isocuprussic acid, and what does this toxin do?The pine needle abortion agents (juniper, ponderosa pine, lodgepole pine) Causes constriction of blood flow to placenta
Why is fescue a problem?toxicity caused by Ingestion of fungus-infected (Neotyphodium coenophialum) tall Fescue grass (Mostly Kentucky-31 cultivar)
what is Neotyphodium coenophialum, and what problems does it cause?If is the fungus which grows on tall fascue grass, and 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) cause peripheral vasoconstriction, and high temps (>89) make the problem worse
with what non-infectious agent do ergot alkaloids coincide? HOW do ergot alkaloids affect the cows?(tall fescue grass) (1) Cause 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 function, Reduced conception rates, Delayed puberty)
what are some clinical signs 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 function, Reduced conception rates, Delayed puberty
do ergot alkaloids/ fescue tox cause abortion?NO! just dec repro efficiency
sores on feet, heat exhausted, and repeat breeder cows might clue you in to what dz?fescue tox/ ergot poisoning
how would you treat fescue tox?Treatment not practical/economically feasible, however, would be Slow-release formulations of thiabendazole and ivermectin to reduce some of the vasoconstrictive effects, and Metoclopramide (to work as a Dopamine-receptor antagonist) (remember, dopamine dec prolactin and ergot alkaloids inc the 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 months, Interseed Fescue pastures with legumes, Do not overfertilize – exacerbates effects of ergovaline. Supplement with 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 cause 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 methemaglobin Which Results in hypoxemic stress in tissues including placenta = late-term abortion
around what time in gestation do nitrates cause 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 with around preg moms?prostaglandins....duh