- Mixture of DNA from 2 different sources (ex. freemartin twins) o Exchange of cells during pregnancy where this happens - Ex. 2 different blood types

- Cattle and sheep - Early exposure: embryonic death, resorption - Later exposure: still birth, hydrocephalus, arthrogryposis

- effects rapidly dividing cells in pigs and dogs - 1st trimester: resorption - 2nd trimester: abortion/mummification - 3rd trimester: few effects

- Blind, micropthalmia - Abortion, stillbirth - CNS, renal and cardiac malformations

- Enzootic ataxia in sheep o Anemic o Infertility

- Cartilage and limb development

- Prolonged gestation - Goiter - hairless

10 – Teratology 2 Flashcards by Danielle Groenendijk

What is abnormal development influenced by?

Dose
Time
Duration of exposure
Species
*functional changes with no more abnormalities=3rd trimester
*if morphological damage=first trimester

How well did you know this?

Not at all

Perfectly

Male manifestations of abnormal development

Spermatogenesis
a. Ex. ergot at high dose
Testis (not a big issue)
Secondary sex traits
a. Ex. *mycotoxin (w/estrogenic properties)=infertility

How well did you know this?

Not at all

Perfectly

Female manifestations of abnormal development

Oogenesis/estrus
Early embryonic death
a. Ex. lead
Failure to implant
a. Ex. dairy cattle on high nitrogen diet (blood urea nitrogen is at high normal)
Abortion
a. Long list: hypoxic, sweet clover poisoning (dicoumarol), lead, plants
Prolonged gestation
a. Ex. iodine
Agalactia
a. Ex. ergot
Malformation
a. First trimester: 500!
Stillbirth
IUGR (inter-uterine growth retardation)
a. 3rd trimester
Mummification of fetuses

How well did you know this?

Not at all

Perfectly

What are some causes of abnormal development?

Genetic
Infectious
Nutritional deficiencies
Poisonous plants
Chemicals and drugs
Mycotoxins

How well did you know this?

Not at all

Perfectly

Genetic causes of abnormal development

Gene mutation
1. Autosomal (recessive, dominant, etc.)
1. Sex-linked (recessive gene)
1. Chromosomal abnormalities (not inheritable=self limiting)
*manifestations could be anything!

How well did you know this?

Not at all

Perfectly

Chimera

Mixture of DNA from 2 different sources (ex. freemartin twins)
o Exchange of cells during pregnancy where this happens
Ex. 2 different blood types

How well did you know this?

Not at all

Perfectly

Blue tongue virus

Cattle and sheep
Early exposure: embryonic death, resorption
Later exposure: still birth, hydrocephalus, arthrogryposis

How well did you know this?

Not at all

Perfectly

Bovine viral diarrhea

Cytopathic
o Abortion
o Early embryonic death
o Placentitis
o Infertility
o Malformation cerebellar hypoplasia
o Eye and jaw defects
Non-cytopathic
o Immunotolerance
*persistent infection

How well did you know this?

Not at all

Perfectly

Parvovirus

*effects rapidly dividing cells in pigs and dogs
1st trimester: resorption
2nd trimester: abortion/mummification
3rd trimester: few effects

How well did you know this?

Not at all

Perfectly

Feline Panleukopenia Virus

Usually death
Ataxia, oculovestibular problems due to cerebellar hypoplasia
o *DDx: in this course=mercury
Hydrocephalus

How well did you know this?

Not at all

Perfectly

Vitamin A deficiency

Blind, micropthalmia
Abortion, stillbirth
CNS, renal and cardiac malformations

How well did you know this?

Not at all

Perfectly

Vitamin E/Se deficiency

Cardiomyopathy
White muscle disease in cattle

How well did you know this?

Not at all

Perfectly

Cooper (malindome)

Enzootic ataxia in sheep
o Anemic
o Infertility

How well did you know this?

Not at all

Perfectly

Manganese deficiency

Cartilage and limb development

How well did you know this?

Not at all

Perfectly

Iodine deficiency

Prolonged gestation
Goiter
hairless

How well did you know this?

Not at all

Perfectly

Veratrum californicum (poisonous plant)

SHEEP (species)
agent: alkaloids cyclopamine, jervine
*reduce neuroepithelial cell mitosis/migration
*reduce chondrocyte proliferation

Lupines (poisonous plants)

*Crooked calf disease
Arthrogryposis
Cleft palate
Spinal curvature (torticollis, scoliosis)
Agent: alkaloid anagyrine

Tobacco (nicotiana) (poisonous plant)

Pigs: cleft palate, arthrogryposis
Agent: anabasine

**Vitamin A toxicity

Mechanism: interferes with neural crest cell migration
Fetal resorption
**Microphthalmia
Spina bifida
Heart, GIT, urogenital defects
*teratogenic at therapeutic dose
**one of the most potent!

Albendazole toxicity

Anti-helminthic
Mechanism: inhibits microtubule formation
Spina bifida
Bone, kidney defects

Organophosphate insecticides toxicity

Embryotoxic, fetotoxic
CNS: learning impairment and behavioural change
*Not as much developmental defects

Organochlorin insecticides (DDT, lindane) toxicity

Mechanism: estrogenic
No implantation
Resorption
Reduced CL formation and reduced progesterone
Reduced sperm
*very difficult to purchase (more if it has been stored and exposed animals)

Many other chemicals (fungicides, herbicides, antibiotics)

Not particularly teratogenic with some exceptions

Griseofulvin toxicity

Not species specific
Antifungal drug (ex. treat ringworm)
Reduced microtubule and mitotic spindle function (mitotic interference)
Abortion, resorption, bone, neural tube, cyclopia, anophthalmia (many systems but mainly CNS)

Cyanide toxicity

- Plant origin - Mechanism: effects energy and oxygen utilization - **Arthrogryposis (limb development needs movement, and there is less movement due to lack of energy) - *if too high=dead

Nitrates toxicity

- Plant origin (ex. drought problem=can get high nitrates) - Mechanism: *effects hemoglobin (oxidizes it) and get methemoglobin formation and anoxia - Abortion - *cows can adapt nitrate tolerance (fetus may not be able to adapt)

Mycotoxins toxicity

- Fungal metabolites - *increasing - Potent=microgram/kg range (not just mg/kg range!) o Fetus is so susceptible - Many effect rapidly dividing cells=ABORTION! o If having an abortion problem can ran a test panel (12 toxins)

Zearalenone (mycotoxins toxicity)

- US problem with corn crops - Estrogenic - INFERTILITY - *pigs more susceptible

Aflatoxin (mycotoxins toxicity)

- Liver toxin o Can not metabolize drugs, chemicals or nutrients - Rapidly dividing cells - *also carcinogenic - Extremely toxic! - *NOT a problem in Canada unless importing fed

Fumonisins (mycotoxins toxicity)

- ‘new’ - Rapidly dividing cells - Other organ systems: lung, liver - *horses and pigs o Horses: neurological component - May cause abortion and resorption of fetuses

Trichothecenes (mycotoxins toxicity)

- Many examples (will go over in a different lecture) - Cytotoxic - Affect rapidly dividing cells - *abortion - **#3 for occurrence in western Canada - *swine

Dicoumarol (mycotoxins toxicity)

- Abortion - Bleeding - *fetus is 3x more susceptible (mother may look normal) o Clotting time in mom, may be slightly increased - *cattle most susceptible - Horses are resistant=not very protein bond=leaves system quickly - Sheep=even higher protein bound=doesn’t even reach the fetus - Ex. in sweat clover bales (mold: coumarin to dicoumarol) - (can get it from milk)

Ergot (mycotoxins toxicity)

- *#1 problem in western Canada - Abortion - Vasoconstriction - *dozen different alkaloids that cause the effects - **species susceptibility o HORSES o Pigs and sheep (less) o Dairy (even less risk) - *agalactiae and prolactin and stimulation of milk production (ex. sheep with NO milk) o Lamb mortality is high (can’t bottle feed everything) - *growth retardation in 3rd trimester (not getting nutrients it needs, morphologically looks normal but just smaller)