In animals, we do various methods for diagnosis for pregnancy. There are mainly 6 methods in which clinical method is most used in cattle/buffalo. While sonography method mainly used in horse and other small animal.
  • Managemental method
  • Abdominal ballottement
  • Clinical method
  • Transrectal ultrasound
  • Radiography
  • Laboratory method

1. Managemental method

This is based on the history of service by a bull or artificial insemination and non-return to estrous. This is not a reliable method.

The animal apparently may not return due to various reasons other than pregnancy.

2. Abdominal ballottement

We can diagnose pregnancy by external palpation of abdomen
  1. Possible to some extent in cows during late gestation (7 months onward)
  2. Palpation of fetuses through the abdomen is possible in sheep and goat only beyond 4 months of pregnancy
  3. In bitches beyond day 55 it is easy to diagnose pregnancy by the palpation of the fetuses

3. Clinical/per-rectal method

  1. This method is most practical and most reliable
  2. Pregnancy is diagnosed by per-rectal examination of the animal and the anatomical changes in the reproductive organs like ovaries, uterus, uterine artery and palpation of fetus is taken as the indicator of pregnancy.
In per-rectal method this organ palpate
  • Cervix
  • Uterus
  • Ovaries
  • Placentomes
  • Amniotic vesicle
  • Fetal membrane slip
  • Palpation of fetus



4. Ultrasound method

There are different types of machines available. The most commonly used machines today are B-mode real-time, meaning that they produce an acoustic image in real time.

They usually range from 3.5 - 7.5 MHz With greater MHz you see more detail but have less depth penetration.

There is more depth penetration with lower MHz, but less detail.

5. Radiography

Sheep and goat, fetuses are visible by day 70 of gestation

Bitches fetal skeletons are visible by the sixth week of pregnancy
 
Fetal skulls are visible by day 45 and the entire fetal skeleton is visible by the end of seventh week of gestation.

Fetal skeletons begin to calcify only after the sixth week in sows and hence radiography should be performed only after this time for pregnancy diagnosis in sows.



6. Laboratory method

The blood or milk progesterone level is used as an indicator of pregnancy in this method. 

Other method also used Such as:-
  1. Progesterone hormone assay
  2. Based on oestrogen 
  3. Cuboni test
  4. Mucin test(vaginal mucosa test)
  5. Phenolsulphonic acid test(Urine test in mare)
  6. Barium chloride test(Urine test in cow)