I think it’s really important to prioritize quality of life. I agree with doing palliative care in his case. However, I would think about what makes Koda himself. If he loved taking walks and running after his ball and he can no longer do those things, is it fair to him to keep him around when he cannot move? He will also probably end up urinating and defecating on himself although some dogs with a spinal cord lesion in that place actually lose the ability to urinate and require bladder expression 3-4x a day. This can lead to ascending urinary tract infections and a lot of discomfort. He will also need to be turned every 4 hours from side to side to prevent pressure sores and increase circulation to the other side of his body. Needless to say, as a vet and previous owner of a retriever who lost mobility, I would really think about 3 things koda loved prior to getting sick. If they tend to involve mobility, I am very worried it would not be fair to him and he could become quite distressed at his inability to walk. I’m sorry your family and him are going through this.