Our expert says:
Something must have scared him at that moment and this can be a once off situation. You need to take measures to ensure that he knows both of you are boss. If you had a very well disciplined dog this is unlikely to happen. I would seek the advice of a behaviourist to help you re-inforce your dominance over the dog.
I think putting the dog to sleep at this stage is a bit drastic but you should do as discussed above.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.