Behaviourial Issues - 3 year old

by Matt
(Chicago, IL, USA)

I am hoping that assistance with some behavioral advice and/or resources for recent issues that have occurred in the past month with our Great Pyrenees can be provided. I very much appreciate any feedback and thank you for all that you do:

My wife & I adopted a Great Pyrenees rescue (2) years ago in August 2018, at the time of adoption the rescue group assumed his age at the time to be around (1) year old, which would make him about (3) years old now. The GP we adopted was a stray who was found abandoned in Arkansas with several health issues, including malnourishment. We nursed all ailments back to full health and he has done absolutely great and been a very happy dog with no behavioral issues at all until a couple incidents that occurred in the past month.

Unfortunately, within the past month our GP has aggressively growled and snapped at (3) different people. This was bizarre as he has been very social and interacted with a bunch of dogs/people with no issues in (2) years. While he has not bitten anyone and I know GP's tend to use their bark to deter and are known to not actually bite, these growling/snapping episodes have resulted in scary situations for both us and our friends that have been involved. To go along with this, the most recent incident occurred in the presence of a toddler, and while our GP did not show any aggression towards the toddler, we clearly do not want to risk further incidents, especially with children.

We are willing and open to listen to any suggestions and are fully committed to working to resolve these issues. We love our dog but are worried about these recent issues.
Thank you for your time and I am looking forward to hearing back from you.

Thanks,
Matt