The normal gestation period of a Siamese cat is about sixty-five days, although this may vary a day or two either side. I like to use day two of the honeymoon as my conception date though with experience of my own girls I may modify this to suit the girl or line in question. I find it easy to remember, nine months pregnancy for humans, nine weeks pregnancy for cats. I have a useful tool on my website which I call my Feline Gestation Calculator, this may be of use when calculating when your girl is due to have her kittens so feel free to use it.
It can be a very exciting and very worrying time when awaiting newborn kittens and I hope some of the worry is taken out of the experience with the aid of this free online tool for working out when the kittens are due to be born. Unfortunately I find that my cats tend not to use a computer when deciding when their kittens are due but prefer to suit themselves. Hopefully though this article and my online feline gestation calculator should help narrow the time to within a couple of days when working out time off from work.
It is not unusual for a maiden queen to go as much as 67 days. If your cat has not given birth by day 72 I would recommend veterinary advice.
How can you tell if your cat is in fact pregnant?
I have written a separate article on this very subject with photographs and details of my experience on this subject. Again please feel free to read my article in helping you decide ‘Is my cat pregnant?’
Once your Siamese Queen has given birth to her Kittens it may be useful to compare their development with some of the kittens at Burnthwaites Siamese by looking at the online kitten diaries that are constantly updated on this website. I find this a useful point of reference when watching my kittens development.