Yeah Chief does that. He has added lip curling to the routine as of late and we are trying to break this altogether because it scares people. We know he loves the attention and it is a happy noise caused by excitement for lovins but we feel it is necessary in our case.
Our Fiona does that rumble sometimes when getting loved on, but she is a little squirrely (adopted and developed some bad habits from previous owners) so we have been handling that aspect of her personality with kid gloves. Our other 8 Rotties (throughout time) did not have this rumble.
Our family loves to get on the floor and wrestle with our boy Yoda.
We say to him like in WWE Wrestling...."Let's get Ready to Rumble"....our boy know's when it's play time it's so funny him rolling around the floor.
He loves to grab our hand or arms,the kids lay all over him he loves it.
Yoda gets louder & louder & we laugh so much.
Play time is a great bonding time for us all.
I know some people not familiar with the Rottie breed don't know how to take the Grumble, they think they are being savage.
Far from the truth, they are awesome dogs.
Some of our friends are scared of our dog,they think when Yoda is playing he is going to attack us.
We are forever trying to teach people about this breed of dog.
It's a shame that we only see these dogs in the news for all the negative things that may happen.
It's hard convincing some people what good dogs we have.
That Grumble sure does make us laugh.