Tortoises are well known for being chilled out pets, taking every day as it comes and never going at full speed. Most people and perhaps most animals would view them as harmless and their tough exterior is just for self-defence. However, as described in the Russian Tortoise cheat sheet (You can visit them here) that dogs and tortoises do not mix well.
From the reptile forums, one owner said “The dog’s natural instinct is to toss the tortoise around and play with it – while he’s doing this he will be puncturing the tortoises internal organs which in turn will kill him. “
As should be the case with any incident where a dog is introduced to another animal, you simply don’t know if they will snap and do something silly or aggressive, our advice to you is to NEVER let these two mixes under any circumstances, no matter how much trust you have in your dog.
If you have one or the other and thinking of adding a new pet to the house, please take our advice and think again.
You can also follow this Reddit discussion on some real life experiences of dogs and tortoises mixing. Most did not end well!