Trevor Donovan is using his dog's heartbreaking death as a teachable moment ... he's here to tell you just how easy it is to stop dogs from suffering the same sad fate.
Trevor came on "TMZ Live" to tell us about his Dogbert's recent passing, and why the disease that killed him is totally preventable. His German shepherd suffered from degenerative myelopathy -- a progressive disease of the spinal cord -- and Trevor says the condition can easily be bred out of all types of dogs.
The last time we caught up with the "90210" alum, Dogbert was already dragging his hind legs ... and Trevor was pissed at the greedy breeders who were too cheap to get their pups tested.
Trevor's still calling for breeders to step up and shoulder some of the responsibility for ridding dogs of the disease ... and advocating for everyone to apply the $40 lab test.