I wonder if anyone can shed any light on a reaction my daughter's dog suffered recently. She is a borzoi 11 months old.

Last week she showed signs of some agitation, unwillingness to be touched on the shoulders. Then she developed spots almost all over her body but mainly on the back and shoulders. They looked a bit like measles and broke open readily. They caused her intense pain and anxiety trying to escape from the irritation. Fortunately they have eased with steroid injections and piriton.

There were 3 possible causes.

1.Ticks were found 14 weeks before and removed.

2. Treatment with Frontline was given 10 days before

3. She was at the groomers 3 days before and washed, shampooed and groomed. I do not know what the shampoo was at the moment.
any suggestions gratefully received!

We can all offer explanations for what's going on but at the end of the day, my advice has to be see your vet.   He should be able to do a skin scrape, if he can't diagnose immediately.   Yes to anti-inflammatories at leas to calm it all down.

She has been to the vet, once the 1st day before the spots erupted and twice a day for the next 2 days.
I am asking if anyone can shed any light on causation.

Could it be a contact dermatitis? Some of plants around can give nasty reactions e.g. giant hogweed althoigh I hope it's not that as the after affects are prolonged especially in sunlight.  Frontline is possibility but woild of expected a faster reaction. Otherwise maybe the shampoo. On off as I hope it is are hard to track

I'd think it was either the Frontline OR an allergic reaction to some ingredient used by the groomer. 

Perhaps you could find some incredibly natural shampoo etc products and give them to the groomer to use, next time, and also find an alternative to spot-on products... if Billy No Mates and natural sprays aren't enough, maybe Bravecto...?

Just for anyone who might be interested, the treatment of steroids and piriton has worked and the pustules are no longer causing her irritation. They are healing up gradually. A suggestion from my trainer was that it may have been the combination of Frontline followed by the shampoo, since both had been used before without issue.

My pure breed golden retriever had a litter of 8 pups 1 was about 8 months old broke out all over her face neck and chest area the vet said it was similar to chicken pox didn't know the cause they went away after a week but left very mild scarring she was the was the only one to come down with that affliction did not cause any health issues later on is very rare most vet's have never seen it.   You could always search the Merck Veterinary Manual I believe it is available to view online for free I warn you it is very large just describe what you put as your topic it will show you (make sure you use canine,feline ect exact animal) otherwise it may come up bulvine) hope this helps