As I said
I am not a breeder but I have read a lot and done some research as issues that have been raised here. I love the breed and consider myself a breed fancier even though I do not breed. I am like you and love to learn all I can about a subject I am interested in and I am obsessed with yorkies so here goes...for what it's worth:
Generally speaking
the female should be larger than the male to reduce the risk of pregnancy complications. How far back do you know the genetics of your male? Are you in touch with his breeder and have you asked her about breeding him? She would be a good resource for you as only she will know what his parents and grandparents genetic histories are and you need to go at least that far back before you breed.
I would find a good mentor if I were you. Is your male's breeder reputable? If so, run your idea by her and get her opinion. Then I would
start looking for a "breed quality" female if you are even considering the possibility of breeding her in the future. I know you haven't made up your mind for sure and it is really too soon in your education about breeding yorkies to do that anyway, but you are smart to cover your bases w/o rushing to get her. I know you want a friend for Gizmo and that is good.
There is a lot to look for when searching for a breed quality female...mostly temperament, health,
genetics and the "frame" of the female as I mentioned in my previous post. If you are not considering showing the female or her offspring then you do not have to be as concerned with the YTCA breed standard but
if you want to produce good looking puppies as well as ones with good dispositions and ones that LOOK like the yorkie then you really need to study the breed standard and learn what a "perfect" yorkie is all the while realizing that there is no such thing as a perfect yorkie.
The breed standard is what show breeders and other breeders use in their quest to "improve the breed". It is nice to get a female with
at least a few champions in her lineage as close to the front of her pedigree as possible as at least this shows that the breeders of her ancestors were looking to
breed to the standard and, while this does not guarantee good quality pups, you have increased your odds of producing some. Are there any champions in your males pedigree?
You will pay more for a breed quality female and it will be harder to find because
a lot of good breeders will not sell a breeding female to just anyone. It takes establishing a relationship with you and a trust so that he/she knows you will only undertake this with the utmost caution and preparation and always with the best intersts of the female in mind.
A reproductive veterinary
specialist can examine the female and evaluate her pelvis and whether she would have an easy time delivering or not. I do not believe pelvic capacity an be accurately evaluated however until the female is full grown so if you want to be "sure" of getting a breed quality female it is best to
buy an adult dog who is at least 8 months to a year and has at least one heat I would guess. In this case, I would have a reproductive specialist evaluate her thoroughly before you make the purchase.
Here is a link to a website with veterinary articles on dystocia (difficult delivery) in dogs and how to minimize the risk.
http://www.intl.elsevierhealth.com/e-books/pdf/974.pdf Small breed dogs in particular seem to have a greater risk and problem with dystocia than other breeds. There is a survey on dytocia dicussed in this article done in South Wales and it was conducted in 12 veterinary practices. Of the 265 cases of dystocia 26% were yorkies, 8% were jack russell and 8% were welsh corgies. The only problem with the accuracy of the survey is that there was no information as to the numbers of these different breeds in the general dog population of the area so there may have just been more yorkies there.
In any case, the experinced breeders on here and elsewhere will tell you that
there is a high risk to breeding any yorkie female so it is very important if and when you decide to think seriously about breeding any female that you
do everything posssible to minimize this risk.
The study also said that 26% of the cases of dystocia were from females who were smaller than the breed average so this is why
it is important to make sure the female is at least the average breed size before considering breeding her. Only very very experienced breeders who know the lines of both male ad female intimately sould ever consider breeding anything under 5 lbs and 6 or 7 lbs is better.
No female yorkie under 4 lbs should ever be bred imo.
This is long enough and should get you started. Please do not feel stupid or be afraid to ask ANY question. Everyone here tries to be nice and do what is best for the breed so every question is a good one because you are trying to learn!!