Reproductive Toxicants and Induced Abortion Flashcards
Reproductive Toxicants:
Teratogens: 1. 2. 3. 4.
- Locoweed
- Poison Hemlock
- Lupines
- Tree tobacco
Reproductive Toxicants:
Abortion-Inducers: 1. 2. 3. 4.
- Locoweed
- Nitrates
- Ponderosa Pine
- Broomweed
Reproductive Toxicants:
Infertility-Causing:
1.
2.
3.
- Locoweed
- Fescue
- Insecticides (?)
Poison Hemlock:
Causes what?
Crooked Calf Syndrome = multiple congenital contractures
Poison Hemlock:
Causes Crooked Calf Syndrome if ingested when during gestation?
50-75 days into gestation
Lupines:
Two main ones?
Anagyrine and ammodendrine
Lupines:
Teratogenic effects:
1.
2.
- Severe limb and spinal deformities
2. Cleft palate
Lupines:
- Teratogenic effects occur if ingested when?
- Not teratogenic in what species?
- 40-70 days
2. Small ruminants
Tobacco:
Teratogenic effects?
Arthrogryposis of the forelimbs and curvature of the spine
Tobacco:
teratogenic effects occur if ingested when?
50-75 days into gestation
Locoweed
What are the two species of locoweed?
Astragalus and Oxytropis
Locoweed
What is the toxin?
Swainsonine
Locoweed
Clinical effects:
1.
2.
3.
- Neuro signs
- Abortion
- Fetal abnormalities - hydrops/arthrogryposis
Locoweed
___% of cattle grazing locoweed can abort
40%
Locoweed
Unique feature with cattle?
They get addicted.
Locoweed
Diagnosis via:
Circumstantial evidence
Locoweed
Relatively (small/large) economic loss
Large! More economic losses than any other plant
Ponderosa Pine:
Toxin?
Isocupressic acid
Ponderosa Pine:
___% abortion rate in cattle grazing pine needles
50%
Ponderosa Pine:
Abortion induced by what clinical effects:
1.
2.
3. Causes abortion if induced when?
- Vasoconstriction at caruncles
- Hemorrhagic placentitis
- > 3 days of gestation
Ponderosa Pine:
Diagnosis via:
history of ingestion + circumstantial evidence
Ponderosa Pine:
Feeding _____ reduces ingestion
corn silage
Broomweed and Snakeweed:
3 toxins:
mono and di-terpenes, saponins, oxygenated flavonol methyl esters
Broomweed and Snakeweed:
Toxicity varies according to:
1.
2.
3.
- Growing conditions
- Stage of growth
- Soil type
Broomweed and Snakeweed:
Clinical Effects:
1.
2.
- Abortion
2. Retained fetal membranes
Fescue:
Specific organism?
Festuca arundinacea infected with the fungus Neotyphodium coenophialum
Fescue:
Toxin?
Toxic alkaloids –> ergovaline
Fescue:
Causes what clinical effect (not the disease, but the effect)
peripheral vasoconstriction
Fescue:
Causes what disease in cattle?
Effects of this disease:
1.
2.
Summer Slump
- Decreased repro eff./infertility
- Decreased milk
Fescue:
Methods to prevent:
1.
2.
3.
- Rotate off of fescue in the summer
- Re-plant pastures
- Avoid seedhead grazing
Nitrates:
Nitrate accumulating plants: 1. 2. 3. 4. 5.
- Johnson grass
- Sudan grass
- oats
- wheat
- corn
Nitrates:
_____ increase toxic nitrate after ingestion –> what condition of the blood?
rumen microbes
methemoglobinemia
Nitrates:
Clinical effects:
1.
2.
3.
- Methemoglobiinemia
- Fetal hypoxia and death
- Late gestation abortions
Nitrates:
Diagnosis?
test ocular fluid of aborted fetus
Nitrates:
Prevention:
Test hay. >1% = toxic
Insecticides:
What kind of insecticies? What is their purpose?
Pyrethroid insecticides.
Combat pests in beef cattle operations
Insecticides:
Methods of application:
1.
2.
3.
- Topicals/Ear tags
- Back rubs
- Sprays
Insecticides:
- Pyrethroids are metabolized by the same group of enzymes that….
- Thus….
- Clear steroid hormones.
2. Potential for reproduction to be altered if sex steroid profiles are disrupted
Insecticides:
Effect on Bull fertility?
None!
Reasons to induce abortion:
1. 2. 3. 4. 5.
- Accidental breeding of young heifers
- Pregnancy in feedlot heifer
- Fetal maceration
- Fetal mummification
- Hydrops conditions
Dropsical Conditions:
1.
2.
- Hydrallantois
2. Hydamnios
Hydrallantois:
Definition?
Occurs when?
abnormal accumulation of allantoic fluid
during 5-20 day period of last trimester
Hydrallantois:
A (fetal/placental) dysfunction?
placental
Hydamnios
Definition?
Gradual accumulation of excessive amniotic fluid
Hydamnios
A (fetal/placental) dysfunction?
Fetal
Which is more common, hydrallantois of hydamnios?
Hydrallantois
Treatment methods for dropsical conditions:
1.
2.
3.
- Induce abortion
- Slow drainage of fluid over 24 hour period (making sure to replace lost fluid)
- constant monitoring via vaginal exam for relaxation of cervix
T/F: Although dangerous, dropsical conditions will most likely not require assistance during delivery
F, will most likely require assistance
Progesterone Sources in Cow:
___ origin for first 150 days of gestation
- Luteal
Progesterone Sources in Cow:
Between days 150-250, the ____ acts as an additional source
placenta
Progesterone Sources in Cow:
in the final month, _____ source declines and ____ source maintains
placental
luteal
Drugs to induce abortion:
- ______: a) b)
- ________: a)
- Prostaglandins. a) estrumate. b) lutalyse
2. Corticosteroids: a) dexamethasone
How does PGF cause abortion? Will occur when?
luteolysis. Any time it is given after day 5-6
How do Corticosteroids cause abortion?
reduce placental P4 production (no effect on CL)
Abortion Strategies: Cow
for days 5-150 of gestation?
1. ______ - result?
- _____ - result?
- Single injection of PGF - abortion in 5-7 days, fertie estrus 3-5 days later.
- Manually disrupt pregnancy - 3-4 weeks for abortion to occur
Abortion Strategies: Cow
For days 150-240 of gestation:
1. Strategy must….
remove ovarian AND placental P4 sources
Abortion Strategies: Cow
For days 150-240 of gestation
- Strategy?
- Efficacy of this strategy?
- Abortion how soon after?
- Combo of corticosteroids and PGF =
* *25 mg dex and 25 mg Lutalyse** - 95%
- 5 days
- Abortion after 120 days leads to _____ in 80% of cows treated.
- Clinical significance?
- retained fetal membranes.
2. usually lost within 7 days, usually not a problem
4% of heifers that have induced abortions will develop ______
fetal mummification
Acute toxic metritis is very (common/rare) as a side effect following abortion induction in cows
very rare
Induced Parturition - Cow
Indications:
1.
2.
3.
- Severe udder edema
- Vaginal prolapse
- Abnormal pregnancy
Induced Parturition - Cow
Drug strategy?
Give 25 mg dex & 25 mg PGF, but if its the final month of gestation one or the other on their own will usually induce parturition in 2-3 days
