Hi Antique
If the little hog is underweight you will need to find a local carer who can over-winter it. But if it’s very tiny and still with the Mother, it’s possible it isn’t independant yet, so you might want to check with your local carer whether it should be left with the Mother until it’s independant. Hopefully Stef might see this and be able to give some advice about that – it’s not my area of knowledge. But I imagine the hoglet might do better staying with mother until weaned, if it isn’t already.
The important thing if using a hot water bottle is to make sure that the hog has room to get well away from it, if it gets too hot. Although it may not need it if it’s inside your house. But it sounds as if the hog really does need checking over if it’s dragging a leg and also the fact that it was out during the day rings alarm bells.
Good luck
