Pregnancy Diagnostics

Question 1

General principles of detecting pregnancy

Answer 1

• Failure to return to oestrus
• Detection of protein/endocrinological changes
• Detection of foetus/foetal membranes
• Physical changes associated with dam
• Maternal changes secondary to endocrinological changes

Question 2

Failure to return to oestrus

Answer 2

• Not useful in bitches - oestrus cycle is 6-7 months (anoestrus for 3-4 months)
• Progesterone profile is the same in non-pregnant as pregnant bitch
• Dam may supress oestrus signs if she has young offspring
• Signs of oestrus may occur during pregnancy

Question 3

Detection of protein/endocrinological changes

Answer 3

• Pregnancy associated glycoprotein
• Lack of decline of progesterone a defined time after mating (not in bitches)
• Species specific pregnancy specific factors
  IFNT in cow/ewe
• Species specific gonadotrophin secretion
  eCG in mare from day 36
• Placental oestrogens (detect in urine/blood)
• Species-specific hormone changes
  Relaxin in bitches

Question 4

Detection of foetus/foetal membranes

Answer 4

○ Rectal palpation
○ Abdominal palpation
○ Ultrasound examination
○ Radiographic examination

Question 5

Maternal changes secondary to endocrinological changes

Answer 5

Absence of oestrus
Changes in cervical mucus
Vaginal wall thinning

Question 6

Examples of Pregnancy Diagnosis in Mare

Answer 6

Lack of progesterone decline after mating
Presence of eCG
Placental oestrogens
Ultrasound to view foetal membranes/conceptus
Rectal palpation - uterine enlargement after 21 days

Question 7

Examples of pregnancy diagnosis in the bitch

Answer 7

Relaxin increases around day 25
No difference in progesterone
Ultrasound to view conceptus/foetal membranes
Abdominal palpation - spherical appearance for day 28
Radiography - foetal mineralisation from day 45

Question 8

Examples of pregnancy diagnosis in the cow

Answer 8

• Transrectal ultrasound - from day 28
• Transrectal palpation - from day 35
• Transrectal detection of foetal membrane (membrane slip) - day 35-40
• Transrectal ballottment of foetus - from day 50
• Transrectal palpation of caruncles/cotyledons - from day 80
• Transrectal uterine artery fremitus - from day 85

Question 9

Accuracy of Rectal palpation in cows

Answer 9

+ Early testing
+++ Positive diagnosis accuracy
++++ Negative diagnosis accuracy

Question 10

Accuracy of Transrectal ultrasound in cows

Answer 10

++ Early testing
++++ Positive diagnosis accuracy
++++ Negative diagnosis accuracy

Question 11

Accuracy of milk progesterone in cows

Answer 11

+++ Early testing
++ Positive diagnosis accuracy
+++ Negative diagnosis accuracy

Question 12

Accuracy of early conception factor in cows

Answer 12

IFNT
++++ Early testing
+ Positive diagnosis accuracy
+ Negative diagnosis accuracy

Question 13

When can you feel the membrane slip in cows?

Answer 13

30-90 days

Question 14

When is a fetus palpable in a cow?

Answer 14

From 90 days

Question 15

When are placentomes palpable in a cow?

Answer 15

from 75 days

Question 16

Pregnancy diagnosis in the ewe

Answer 16

• (Early pregnancy factor – from day 2)
• Failure to be raddled - day 16-19
• (Elevated milk or plasma progesterone day 18-22)
• Transabdominal ultrasound - from day 30 onwards
  ○ Detection of fluid filled uterine horn
  ○ Later detection of cotyledons / carruncles
  ○ Slightly later examination used to increase accuracy and to determine the number of foetuses
• Foetal pulse detector with doppler ultrasound - from day 80
• (Palpation of caudal uterine artery – from day 80)
• (Detection of pregnancy cervical mucus – from day 80)
• Enlargement of abdomen and udder -from day 100
  Transabdominal ballottement of foetus - from day 100

Question 17

Pregnancy diagnosis in the sow

Answer 17

• Failure to return to oestrus - day 18-24
• Elevated plasma progesterone - day 22-24
• Elevated plasma oestrone sulphate – from day 25
• Transabdominal B-mode ultrasound - from day 20
  ○ Detection of fluid filled uterine horn
  ○ Detection of embryo later
• Foetal pulse detector with doppler ultrasound - from day 30
• (Transrectal uterine artery fremitus - from day 40)
  (Vaginal biopsy – from day 40)

Question 18

Pregnancy diagnosis in the mare

Answer 18

• Failure to return to oestrus - day 18-24
• (Elevated plasma progesterone day 18-20)
• Transrectal ultrasound from day 12 (15 common)
• Transrectal palpation from day 21
• Plasma equine chorionic gonadotrophin from day 60 – 120
• Transrectal ballottement of foetus from day 80
  (Plasma or urine oestrogen from day 150)

Question 19

Pregnancy diagnosis in the bitch

Answer 19

• NOT a lack of return to oestrus
• NOT elevated plasma progesterone
• Transabdominal ultrasound - from day 25
• Plasma relaxin - from day 25
• Plasma acute phase proteins - from day 35
• Abdominal palpation for discrete swellings - day 28
• Radiographic examination - from day 45
• Transabdominal ballottement of the foetus - from day 50