Reproductive Toxicants Flashcards
What plants are teratogens?
Locoweed
Poison hemlock
Lupine
Tree tobacco
What plants can cause abortions??
Locoweed
Nitrates
Ponderosa pine
Broomweed
When does poison hemlock cause teratogenic effects?
50-75days in gestation
What syndrome does poison hemlock (conium maculatum) cause?
Crooked calf syndrome
Multiple congenital contracture
What teratogenic effects do lupine effects?
Severe limb and spinal deformities
Cleft palate
Ingestion of lupine between _________ days causes severe limb and spinal deformities?
40-70
T/F: lupine are not teratogenic in small ruminants
True
What teratogenic effects does tobacco plant have?
Arthrogryposis of the forelimbs and curvature of the spine
Ingestion between 50-75 days
What are the species of locoweed?
Astragalus
Oxytropis
What affects can locoweed have on reproduction?
Neurologic signs
Abortion
Fetal abnormalities — hydrops/arthrogyroposis
Up to 40% of grazing cattle may abort
What is the toxic principle in ponderosa pine?
Isocupressic acid
What does ponderosa pine cause in cattle that graze the pine needles?
50% abortion rate
—> vasoconstriction at caruncles
—> hemorrhagic placentitis
—> >3days of ingestion
What plant contains mono and di-terpenes, saponins , and oxygenated flavonoids methyl esters?
Broomweed or snakeweed
Ingestion of broom week causes what in the pregnant cow?
Abortion and retained fetal membranes
What fungus can infect fescue and causes peripheral vasoconstriction ?
Neotyphodium coenophalium
What is another name for the decreased reproductive efficiency and infertility/ decreased milk production cased by fescue toxicosis?
Summer slump
What plants accumulate nitrates?
Johnson grass Sudan grass Oats Wheat Corn
When are you most likely to see nitrate toxicity and what are the clinical manifestations?
Drought periods
Fetal hypoxia and death
Late gestation abortions
How can you confirm nitrate toxicity?
Test ocular fluid of aborted fetus
T/F: nitrates cause a methemoglobinemia leading to fetal hypoxia and death
True
Common product used in beef cattle operations to prevent flies, ticks and lice?
Pyrethroid insecticides
— applied topically as back rubs, sprays, or ear rages
How are pyrethroids metabolized ?
By the enzymes that clear steroid hormones
—> has potential to disrupt sex steroid profiles (if used in correct dosages, there is no evidence that it causes harmful effects on bull fertility)
What are indications for induced abortion in cattle?
Accidental breeding of young heifers
Pregnancy in feedlot heifer
Fetal maceration
Fetal mummification
Hydrops
What are the dropsical conditions?
Hydrallantois
—abnormal accumulation of allantoic fluid during 5-20day period of last trimester
Hydamnios
—gradual accumulation of excessive amniotic fluid
—fetal dysfunction
How can you treat dropsical conditions?
Induce abortion
Slow drainage of fluid (24hr period)
Constant monitoring of dam (vaginal exam for relaxation of cervix, delivery will likely require assistance)
What are the sources of progesterone in the cow during gestation?
Luteal — during first 150days of gestation
Placenta — 150-250days
During final month P4 from placenta declines and CL maintains pregnancy again
What drugs can induce abortion?
Prostaglandins (cause luteolysis)
—estrumate
—lutalyse
Corticosteroid (reduce placental P4 production)
—dexamethasone
What is the best choice for inducing abortion during day 5-150 of gestation?
PGF
Single dose will cause abortion in 5-7days, fertile estrus occurs 3-5days later
What is the best method of inducing abortion during day 150-250 of gestation?
Corticosteroids AND PGF
—> disrupt both placental and luteal P4
Abortion after day 120 leads to ________ in 80% of cows
Retained fetal membranes
What are indications for induced parturition in the cow?
Severe udder edema
Vaginal prolapse
Abnormal pregnancy (hydrops)
How can you induce parturition?
Give dexamethasone or PGF ALONE in final month of gestation —> parturition will occur in 2-3days
