Wolves do not heal properly. Upon being given any type of meat (uncooked, rotten, and cooked) they enter breed mode, regardless of their health. You can tell this by the state of their tail. Sometimes, when you exit the game and reopen it, the tail goes back to the highest position, but the dog still is on low health (you can tell it by the whimpering sound effects, and they also die pretty easily), however, this doesn't always happen. This makes wolves very annoying to deal with in this beta.
Thank you for your report!
We're actually already tracking this issue under MCPE-65604 so I've requested this report be resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki