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Dogs first evolved around 12,000 years ago. They’re one of only about a dozen animals that have ever shared a close relationship with humans. Today they vary dramatically in size, shape, colour, and behaviour. No other species shows such a range of individual characteristics. But regardless of their size, the gestation period for dogs is the same, about 63 days.
At just over 2 weeks since our Golden Retriever conceived, she’s already a quarter of the way through her pregnancy. Inside her uterus an amazing process is underway. The embryonic ball of cells turn in on themselves in a process called gastrulation. As the cells continue to divide and multiply they need instructions, a trigger to tell them what type of cells they should become, and whereabouts in the embryo they should go. Gastrulation is one of the greatest wonders of nature!
At 3 weeks since conception, the embryos are about the size of a pea. Our dog is now showing outward signs of her pregnancy. But even dogs who are not pregnant can sometimes exhibit such signs. This odd behaviour sometimes referred to as pseudo, or phantom pregnancy, goes back to the dog’s distant past, for these embryos, along with every dog on the planet, all descend from the grey wolf.
Clip from the documentary “Animals in the Womb”.
Watch it here – https://youtu.be/XaZW7bbmc9I