Teratology

Question 1

Define Teratology

Answer 1

Study of congenital defects/abnormal formations (Foetal “Monsters”

Question 2

What is a Teratogen

Answer 2

Agent/influence causing physical defects in developing embro/fetus

Question 3

What is Congenital

Answer 3

Present at birth

Question 4

What is Agenesis

Answer 4

Complete failure of development

Question 5

WHat is a syndrome

Answer 5

A group of typical, concurrent or not, symptoms and signs (not a single disease)

Question 6

What is Aplasia

Answer 6

partial failure of organ development or defective development / complete absence of a structure.

Question 7

What is Ectopia?

Answer 7

Displacement/malposition of an organ or tissue

Question 8

What is Palatoschisis

Answer 8

Cleft Palet

Question 9

What is Cheiloschisis

Answer 9

Cleft lip

Question 10

What is syndactyly

Answer 10

Fusion of 2 or more digits

Question 11

What is Amelia

Answer 11

absence of one or more limbs

Question 12

What is Polumelia

Answer 12

Extra limbs

Question 13

What would be a possibility if Hyperthermia during neural fold closure?

Answer 13

High risk of anencephaly (absence of brain)

Question 14

What are some defects due to foetal hypoxia?

Answer 14

Defects due to hypoxia include:
Asphyxial foetal death
Cerebral/adrenal/renal/hepatic anoxia-ischaemia  injury
Intra-uterine growth retardation (IUGR)
Meconium inhalation
↓ placental exchange area  hypoxia, can be due to:
Retroplacental haemorrhage
Pre-eclampsia (maternal hypertension & placental ischaemia)
Placental infarction, umbilical cord entanglement/twisting
↓ uterine blood flow e.g. smoking  low birth weight
Placental insufficiency e.g. twin pregnancies (esp. equids)

Question 15

What are some risks with Pestiviruses?

Answer 15

Bovine pestivirus (bovine viral diarrhoea virus) (BVDV)
Infection ~150d gestation results in cerebellar hypoplasia as seen in feline parvovirus
Much earlier gestation, but equivalent stage of development
Other possible terata with BVDV:
Pulmonary hypoplasia; alopecia
Retinal dysplasia/microphthalmia
CNS myelin deficiency
Ovine pestivirus (Border disease virus)
10-30d placentitis (death, resorption, mummification)
<80d: CNS hypomyelination, hairy fleece
Porcine pestivirus (classical swine fever virus)
Similar lesions to BVDV, including cerebellar hypoplasia

Question 16

What could an iodine deficiency during gestation lead to?

Answer 16

Foetal iodine deficiency can lead to congenital goitre (enlargement of the thyroid gland)
Lambs, goat kids & foals
Maternal diet deficient in iodine or due to ingestion of goitrogenic plants e.g. Brassica spp. (rape, kale)