Thank you everyone - the vet administered a cocktail of drugs to cover many eventualities yesterday afternoon. As he put it we must look at symptoms and approach "with a straight bat" not coloured by previous experience...so...we are hoping it is a straight forward viral infection...very high temp (over 40 degrees at first) elevated heart rate and breathing but good mucus membrane colour and capillary refill. Grass sickness was mentioned but heart rate has lowered and as temp decreases she is eating very well. Late last night her temp was 37.5 and this morning 37.8...the cocktail of drugs will work for 24 hours so I must take vitals all over weekend and if temp spikes again vet will come out and make further decisions. So fingers crossed your vibe action has helped!