Zazzy worries

Zazzy cut her right front foot between the pads, it was a slice that took a while to heal because putting weight on the foot (and when she bounces around I guess that is quite a significant amount of pressure!) kept opening it up again. Unlike my other two who would have been on three legs and worrying about it, she didn't notice it at all. She is a very good girl and lets me fiddle around cleaning it as much as I want, and never tried to remove bandages, however I couldn't make any bandage strong enough to stay on her for more than a couple of minutes when I took her out, even when keeping her on a lead. I guess I underestimated her exuberance and joy for life, which she shows by bounding around, and restricting her exercise just made her bounce more around the house..... Anyway the cut seemed to be healing at last. Then yesterday I had an awful shock because when I woke up, my beautiful exuberant dog could hardly move. Her hind legs could not carry her weight, and she lay on her side on the ground with all four legs stretched straight out in front of her. I gathered her up in my arms and rushed her to the vet. By the time I eventually got to see the vet, she could stand and walk a bit. Frustratingly, the vet could not find anything wrong. The only unusual thing that has happened to her is the cut foot, so I wondered whether infection might have caused this response. Typically for Zazzy, she really made me laugh as she had her temperature taken for the first time, which obviously caused her some surprise as the thermometer was (ahem) inserted. Instead of the usual scrabbling/running away response the vet normally gets, she said Zazzy just turned her head to look at her with profound distain and disappointement. Her temperature was 102.5. Zazzy is on antibiotics and had an anti-inflammatory injection. I will take her to the osteopath as well to have her back checked out. She seemed pretty much back to normal by the evening although I will keep her as quiet as I can for a few days, until she has had her back checked, just in case she has had a back trauma, even though I can't see how or when that could have happened. Since cutting her foot she has been made to take it easy. Any suggestions from anyone who has seen something similar would be welcome!