Sorry to come back to this, haven't been able to face coming on here for a while, been on a bad guilt trip, there were things I should have picked up on - she had a sore teat, I thought the other goat had stood on her, maybe panicking when she kidded ( didn't have a kidding date and missed it, was having to dash to a hospital appointment when I found she'd kidded so had to leave them together).
she wouldn't let the kid suck but would let me milk her, I tried the udderlyeze(?) milker on her but she had a sore round the top of the teat, I thought I'd caused that with the suction. then I saw the kid feeding off her, so I just presumed everything was OK and left them to it. Maybe the kids vigourous sucking brought the infection to a head, thats why there was blood there.
It was only later I remembered the dog running in the field, about 10 days before she kidded, they'd all panicked and gone through the electric fence, some forcing their way through the gate (I'd got there and opened it but too narrow for 2 goats at once) some scrambled over the drystone wall. I am guessing this was the cause, but as she'd kidded OK I'd forgotten that, but she could easily (probably) have bumped herself on the wall, though they all seemed OK when they'd calmed down.
Her sister has kidded, one female, but she isn't a patch on Abi.