El psychological pregnancy in bitches it is something that bitches that have not been spayed suffer, since it is something that happens after heat. It is a problem for them, so it is another reason why it is a good idea to sterilize them, since we are also saving them uterus infections, unwanted pregnancies and other problems.
But if we talk about psychological pregnancy, it is something that can occur as a legacy of survival in bitches. If another bitch dies, they would be able to breastfeed their young, so they would have milk anyway, and hence after heat, what they call psychological pregnancy can occur.
Some of the physical symptoms that we can see in them are those of abdominal swelling and bloating. The breasts also swell and milk appears on many occasions, and they may have mucoid vaginal discharge. If we notice any of these changes, we should take her to the vet. This is a hormonal imbalance that will also affect it psychologically, so we will see the dog more apathetic, and even more aggressive or annoying.
Sometimes these bitches too create a nest in which they consider that they will be comfortable during pregnancy. If they are outside they may dig a lot, and inside the house they may gather things in a place to lie there. These are too many changes not to take them into account if they occur in our dog.
In any case, faced with such a change, we must take her to the vet to estimate what we should do. And if we want to prevent this from happening, the best is always prevention. That is why sterilization is recommended in bitches, which gives them a much higher quality of life and avoids many of these diseases and changes.