Gravidity of Balinese cats
The ovaulation is normally induced ba the mating and takes place 24-50 hours after the mating. Often it takes more than one mating within 2-3 hours to produce enough hormons for inducing the ovulation. It is not possible to draw conclusions from the lenght of the heat to a successful mating. The sperms reach the eggs in the oviducts where fertilisation takes place in the two oviducts. After fecundation the eggs begin to devide and migrate slowly down to the uterine horns. They implant in the wall of the uterus after about 12-14 days as so called blastocystes.
The Blastocystes start to differentiate and develop to an embryo. All important organs start to develop. After 18 days, tight lacings of 1 to 1,5cm can be felt in the uterus (only by an experienced expert). After week 5 this disappears again.
After 20 days, the cats teats grow longer and rounder and begin to pink up. This is a first sign that the cat is gravid. (However pseudopregnancy shows the same signs). After 4 weeks the small embryos have a size of about 2,5 cm. Normally the cat is calm and relaxed during the first weeks of her pregnancy. Only in rare cases signs of indisposition occur.
Gradually, now the belly of the cat enlarges and the body weight increases. The development of the nipple area is starting too. The nutrition of the cat should be adapted to the increased need. Often kitten food is given, because this food is rich in energy.
The embryo is growing very quickly during this period and has a size of about 7 cm after 6 weeks. On and after day 32-35, the activity of the heart is already detectable with ultra sound.
The belly of the cat has now a remarkable size (at least if there are more than 3 kittens expected). The cat is sleeping a lot and should be kept calm and free of any stress. Large jumps can be dangerous now. A suitable box can already be prepared, in order to adapt the cat to the intended home of her kittens.
At day 50 the foetus starts with reflectory movements. This can be seen and felt by carefully touching the cat's belly. On day 45 at the earliest, the skeletons of the kittens are detectable with x-ray.
At the end of the gravity the cat often is very much attached to "her" person and always stays at her side. The cat often shows more tolerance towards other cats and starts to groom them. The gravid cat often searches around for a suitable home for her kittens.
The belly is now tight and full and starts to lower to the back. The nipple area is strongly developed, in the last 1-2 days the milk production can already start. In the last 1-2 days before delivery, the cat shows restlessness. The cat is going often to the litter box and the litter tray and often does not eat anymore. In many cats at 12-24 hours before birth, the boy temperature is decreasing for 1 degree Celsius .
Delivery initiates with first labours, normally after 63-65 days. (Variations between 59 and 72 days are possible). After birth the kittens have a size of about 14 cm. The weight varies between 60g and 120g. Kittens with a weight at birth below 60g often do not surive the first weeks. Kittens that are too large may make a Caesarean section necessary. The litter size is between 3-4 kittens. Especially the first litter of a cat is often smaller, but also larger litters (5-7 kittens) are quite often seen with orientals.