Please help!

Two days ago my dog was fine then her necked rapidly swelled up and she laid on her side with her tongue out. I gave her some Benadryl and took her to the vet. By the time we arrived at the vet the swelling was gone and her vitals were fine. Vet said to give her Benadryl every 8 hours and watch her closely. She was fine that night, fine when I saw her in the morning, but then when my wife was downstairs it happened again. My wife took her back to the vet, same thing, swelling gone, vitals fine. Vet said if she was stung by a wasp it could be prolonged allergic reaction so my wife took her home. This morning the same thing, fine when I saw her but had the same reaction with the swelling and this time she was whimpering. I don't have any idea what this could be, any help would be appreciated.

Hello - if this is an allergy and your dog is continually meeting whatever chemical they are allergic to, this could be a real problem.  It sounds as though it may be a good idea to ask your vet about having anti-histamines in at home on an ongoing basis, just in case.  These may need to be prescribed for purpose.  It may also be that your vet thinks it's worth radiographing or examining the throat under GA in case there might be some underlying problem that you are not aware of.  When such an unusual idiosyncratic reaction is seen in a vets, it my be that there are specialists that your vet can contact who may have seen similar cases, in order to research other available investigations and treatments.  Please will you let us know how you get on?