My dog (two and a half) spend a day with a friend on Friday as we had to be in the city for the day. She had two long walks, seemed fine when she got home and yesterday morning. Early evening yesterday a friend called round with my dog's great pal, another young terrier. They played like mad and then my friend offered to take Vixdog out for a short walk with hers. While on the walk friend noticed Vixdog limping, by the time she got her back to us she was limping badly. My friend is very caring and careful, she hadn't noticed any sudden movement or squeak, or anything that might have led to the limp. At first we thought maybe she'd just had too much walking the day before, perhaps her paw was sore, perhaps her muscles etc. As the evening wore on she really looked in pain and wouldn't eat, so we took her to the OOH vet. He gave a painkiller jab, and thought she might need an x-ray on Monday. This morning her whole foot was badly swollen, and she looked really unwell and in pain- straight back to the OOH vet (we saw a different vet on call) who was baffled. She has a really high temperature, so she's had antibiotics, and more painkillers. The foot is hot and swollen, she is panting and her eyes look sticky and dull. Both vets (and DH and I) have looked gently all over the foot and there is no obvious puncture wound. It is a mystery- anyone had anything similar? We are in a rural area and she did briefly wade in the river as it runs into the sea yesterday. I wondered about Weever fish, but they are normally further out, and she surely would have squealed and swollen up right away? Vet asked if a cat could have bitten her, that is a no. An adder bite would have made her very ill very quickly. Spider? Anything else? I am really worrying, she isn't getting out of bed at all and looks very unhappy.