I did some testing and searching and I'm not sure what could be the problem. I did test them on the test server that has the upcoming update and they are fine. So I hope the next update will fix it.
I could only speculate from your posts that starvation might be a cause. In that case, your log of the day where this happened might help you to find out what caused this. When a pet gets into serious danger of hunger, the master receives a warning.
It was unfortunate that you lost your first Tusker.
May your new companion bring you wonderful days.