Hill Rise Rabbitry: Bucks or Does?

Young buck. Note the gap.

Young doe. Note the slit that leads directly to the anus.

Up until about a year ago, I thought that it was impossible to determine the sex of kits that were any younger than 10 days old. In many cases, it could be impossible until 5 or 6 weeks. A year ago, I came across an image and some information that changed that idea. It is actually possible to sex kits in the first 2--sometimes 3--days of life. The reason this works is that the hormones which trigger the doe's labor actually affects the kits as well, which causes their genitals to swell (it can also make their teats swell, too, even on males). I knew about this phenomenon in humans, but hadn't ever considered it for rabbits.

The image I originally saw had actually been passed around the internet quite a bit, but I finally managed to track down the original photographer, Moorcroft Stud Rabbits. With the original post, she said, "[Y]ou can see a distinct difference between the bucks 'gap' and the does running str[ai]ght into the anus."

Last spring, I decided to give it a try. These are my results from last year:

Tri# 6 (1 day old) - Doe (confirmed)

Tri#5 (3 days old) - Doe (confirmed)

Ott - Buck (confirmed)

Poppy - Buck? (confirmed)

Pee on buck makes it look like a doe.

I had several others, but I unfortunately forgot to write down whether they were confirmed. In some cases, I forgot to maintain the Sharpie marks I was using to distinguish them. One thing I did note was that if the kit pees, it makes it really hard to tell. So, if you're photographing these to have others help you, make sure that the parts are as dry as possible.

So, now we come to our latest litters. I'm not the best at this, so don't take the following determinations as gospel. I'll confirm or refute these when the kits are old enough to sex by the traditional method.