Pregnancy Diagnosis in Bitches
1. Nagargoje Shital Dhanaji
MVSc Scholar, Division of Physiology and Climatology
ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly (U.P).
2. Dr.Manojkumar Pande
MVSc Scholar, Division of Vetterinary extension
COVAS,Parbhani (MH).
3. Dr.Vijay Panchal
MVSc Scholar, Division of LPM,
MVC,Mumbai (MH).
Introduction:
In canine gestation period lasts in 65 ± 1 day. To all the animals this is a very crucial time. During gestation pregnant bitches always needs extra care and management. Following conception, the animals require not only extra attention from their owners but also veterinary medical supervision of the bitch and foetuses to avoid or diagnose diseases promptly. For the proper care of bitches the pregnancy diagnosis is very important.
Methods of Pregnancy diagnosis:
Pregnancy can be identified by fallowing methods-
Palpation (examination by the veterinarian day 28-35)
Vaginal cytology
Hormonal diagnosis [A serum relaxin test (after day28)]
Ultrasound examination
Radiography after 44 day
Abdominal palpation:
It can be done with the greatest accuracy between days 25 and 35.
Obesity or a stressed abdominal wall makes it more difficult to palpate.
The embryonic vesicles can be distinguished during this period as distinct round structures 1–3 cm in diameter.
After day 35, the gestational sacs are big enough to begin to invade each other, making it even more difficult to palpate distinct sacs.
Nevertheless, palpation cannot be used to differentiate uterine swellings associated with uterine disease from the normal development of the uterus associated with pregnancy.
The uterine swellings enlarge after day 35, resulting in a confluence, rendering the palpation of the pregnancy even more inaccurate.
It is the most effective clinical laboratory method for the management of bitch breeding, control of the oestrous cycle and diagnosis of pregnancy but not for the estimation of the date of whelping.
Ultrasonography:
The ultrasonography is one of the principal imaging techniques use for veterinary practice.
It is an excellent way to diagnose pregnancy early on Day 19 after breeding to 21 days post-LH peak in the bitch, which is very sensitive, specific imaging method.
If the LH peak is unknown, Ultrasonography for pregnancy detection should be performed at approximately 30 days after the last known breeding. It is an accurate, safe for animal, puppies and the operator.
USG can be used for prediction of the parturition date, detecting foetal resorption, foetal abnormalities, developmental stages of the foetus, Viability of the puppies, detection of heartbeats, Interpretation of Postpartum uterine involution in the bitches, to diagnose and manage reproductive disorders of the uterus.
Foetal heartbeats are first detected 23 to 25 days after the LH peak or 16 days after the onset of cytological diestrus.
Foetal heart rates that are below 130 beats per minute indicate poor puppy viability, and the pregnancy requires intensive monitoring. Normal foetal heart rates at term are often greater than 200 beats per minute.
Radiography:
By day 45 of pregnancy, it can be used to diagnose pregnancy after foetal mineralisation has begun.
Before day 45, only a soft tissue density in the caudo-ventral abdomen can be observed, which is indicative of pregnancy but can’t be differentiated from other causes of uterine enlargement (pyometra, mucometra, etc.).
After day 45, evaluation of which bones are calcified may help to determine the stage of pregnancy, but there are considerable variability and individual variance, making radiograph a less than ideal method of gestational ageing.
Radiography is a reliable method for determining foetal numbers but may underestimate the litter size in very large litters.
Radiography will also enable the foetal skeleton to be evaluated for signs of foetal death (i.e., foetal skeleton collapse, or uterine gas).
Due to the mobility of the uterine horns, radiography does not assess the foetus presentation.
In the bitches, elevations of progesterone are not distinctive whether a bitch is pregnant or not. However, the levels of progesterone can be used to indicate a failure of ovulation.
Prolactin levels in pregnant bitch increases; however, there is no commercial test available.
Relaxin is not produced in non-pregnant bitches at all; therefore its appearance can then be used to diagnose pregnancy. Relaxin seems to be the only hormone observed specifically for pregnancy in carnivores and is produced by the foeto-placental unit.
Relaxin is best measured after days 19–21 of pregnancy by radioimmunoassay or enzyme-linked immunosorbent assay techniques; however, there may not be enough relaxin produced in early pregnancy to register as positive on the test, resulting in a false negative.
Further care should be taken when interpreting positive tests, because relaxin can still be developed even after foetal death, resulting in a false-positive test. It is not as accurate as ultrasonography.
If during the appointment, the bitch is found to be non-pregnant, a medical workup will be examined for the failure of conception.
This is a good time to remind that they are exposed to any infectious disease or not.
The bitch should remain in the setting of home, kennel, or cattery and should not share residential or exercise areas with animals either in competition or training. This includes shared areas for exercise even if direct contact is prevented.
