Took a walk with the horse in the evening. Two weeks after having left the clinic she is so much better, I think she walks as fine as she hasn't done for years...
Also she looked quite happy to be out again and was as chirpy as can be. Makes me think this is worth the 2000 quid that I will pay for the vet bills.

P.S.: Last year, same tree, same kind of fog. Did not do this on purpose! Just happens to be we had the same weather last year and I cycled the same route...